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Hydro-system related mortality and in-lake behaviour of migrating adult sockeye salmon in the Seton-Anderson… Roscoe, David William 2009

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HYDRO-SYSTEM RELATED MORTALITY AND IN-LAKE BEHAVIOUR OF MIGRATING ADULT SOCKEYE SALMON IN THE SETON-ANDERSON WATERSHED, BRITISH COLUMBIA. by David William Roscoe B.Sc., The University of Lethbridge, 2006  A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in The Faculty of Graduate Studies (Forestry) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver)  July 2009  © David William Roscoe, 2009  ABSTRACT Pacific salmon carry out long distance spawning migrations from ocean feeding grounds to natal freshwater streams. Because many salmon rivers are dammed, fishways are required to enable individuals to pass through dams and reach upstream spawning areas. However, many fishways are ineffective, preventing or delaying upstream passage, suggesting a need to monitor and evaluate these facilities. I conducted a literature review of studies evaluating the effectiveness of fishways to assess what taxa and life-stages have been studied, the questions asked during evaluation, and how these varied by time or geographic location. The majority of studies focused on adult fishes (68%) and the order Salmoniformes (58%). Many studies evaluated exogenous mechanisms of passage failure, such as environmental or structural factors (69%). Few studies examined endogenous (i.e. physiological) factors or postpassage consequences, information that is necessary to understand passage failure and inform mitigation strategies. A field study was carried out to evaluate the impact of a dam and fishway on the spawning migrations of sockeye salmon in the Seton-Anderson watershed in British Columbia. I used acoustic telemetry, non-lethal biopsies, and an experimental approach, releasing fish either up- or down-stream of the dam and comparing behaviour and mortality between the two groups. Fishway passage efficiency was 80% and most failure was associated with failing to locate the entrance. Attraction to the fishway entrance varied with water discharge volume from the dam, with the longest delays and highest failure rate at the highest discharge. Fish released downstream of the dam suffered higher mortality in lakes upstream of the fishway (27%) compared to fish released downstream of the dam (7%), suggesting post-passage consequences that reduce survival. Sockeye migrating through two thermally stratified lakes upstream of the dam were used as models to investigate the hypothesis that temperatures selected by sockeye salmon are related to an individual’s reproductive status and energy reserves. As predicted, I found that energy and estradiol were positively related to thermal experience.  ii  Sockeye salmon with low energy and advanced reproductive status may have selected cooler temperatures in order to reduce metabolic energy expenditure and avoid overripening of gametes.  iii  TABLE OF CONTENTS ABSTRACT...........................................................................................................................................ii TABLE OF CONTENTS..................................................................................................................... iv LIST OF TABLES ................................................................................................................................ v LIST OF FIGURES.............................................................................................................................. vi ACKNOWLEDGEMENTS................................................................................................................vii CO-AUTHORSHIP STATEMENT ..................................................................................................viii CHAPTER 1: Introduction ................................................................................................................... 1 General introduction and background .................................................................................... 1 Thesis overview and objectives .............................................................................................. 4 References ................................................................................................................................ 7 CHAPTER 2: Effectiveness monitoring of fish passage facilities: historical trends, geographic patterns, and future directions ................................................................................. 13 Introduction ............................................................................................................................ 13 Methods .................................................................................................................................. 16 Results .................................................................................................................................... 17 Discussion .............................................................................................................................. 20 Conclusions ............................................................................................................................ 32 References .............................................................................................................................. 42 CHAPTER 3: Fishway passage and post-passage mortality of up-river migrating sockeye salmon in the Seton River, British Columbia ...................................................................... 55 Introduction ............................................................................................................................ 55 Methods .................................................................................................................................. 57 Results .................................................................................................................................... 62 Discussion .............................................................................................................................. 65 References .............................................................................................................................. 77 CHAPTER 4: The effect of dam spill discharge on attraction of sockeye salmon into the Seton Dam Fishway, British Columbia............................................................................. 83 Introduction ............................................................................................................................ 83 Methods .................................................................................................................................. 84 Results .................................................................................................................................... 88 Discussion .............................................................................................................................. 89 References .............................................................................................................................. 96 CHAPTER 5: Do levels of reproductive hormones and gross somatic energy influence thermoregulatory and migration behaviour of adult sockeye salmon migrating through stratified lakes?......................................................................................... 100 Introduction .......................................................................................................................... 100 Methods ................................................................................................................................ 102 Results .................................................................................................................................. 108 Discussion ............................................................................................................................ 111 References ............................................................................................................................ 125 CHAPTER 6: Conclusions ............................................................................................................... 131 References ............................................................................................................................ 135  iv  LIST OF TABLES Table 2.1. Terms describing general research question types from summary of fish passage facility evaluations................................................................................................35 Table 2.2. Classification of 96 journal articles concerning fish passage facility evaluations in terms of taxa and life-stage studied and types of general research questions included..............................................................................................................................36 Table 2.3. Summary of categorization of 96 peer-reviewed articles about fish passage facility evaluations carried out in three geographic areas. Articles were categorized in terms of taxa, life stage and general research questions studied........................................39 Table 3.1. Location and detection efficiency of acoustic telemetry receivers used to track Gates Creek sockeye migrations in 2007...........................................................................72 Table 3.2. Results of two-way ANOVA comparing blood biochemistry, energy and length between male and female sockeye salmon sampled immediately after capture from the fishway (‘control’) or sampled following 5-hour recovery period in a net-pen (‘net pen held’). Means (± SE), sample sizes and P-values are shown.....................................73 Table 3.3. Fate of Gates Creek sockeye salmon captured from Seton Dam Fishway and released either up- or downstream of the dam...................................................................74 Table 5.1. Range of values of mean, 5th percentile (T5) and 95th percentile (T95) temperatures experienced by 24 sockeye salmon during migration through lakes to spawning areas.................................................................................................................117 Table 5.2. Parameter estimates (slope or intercept) and probabilities (in parentheses) from regressions predicting travel speed or measures of temperature experience using GSE and sex (males and females) for sockeye salmon migrating through Seton Lake, Portage Creek and Anderson Lake..................................................................................118  v  LIST OF FIGURES Figure 2.1. Number of peer-reviewed journal articles concerning fish passage facility evaluations by year. All studies were conducted in one of three geographic areas shown.................................................................................................................................40 Figure 2.2. Percentage of fishway evaluation articles published in different time periods that included four types of research questions...................................................................41 Figure 3.1. Map of the Seton-Anderson watershed in Southwestern British Columbia, Canada showing the location of hydroelectric facilities on the Seton River and the spawning channel at Gates Creek......................................................................................75 Figure 3.2. Map of Seton River showing 4 release locations of telemetered sockeye salmon in 2007...................................................................................................................76 Figure 4.1. Map showing the Seton-Anderson watershed and the location of the Seton Dam near Lillooet, British Columbia, Canada where sockeye salmon tagged with telemetry transmitters were tracked to study passage behaviour in 2005 and 2007. Insets show the location of the study site in Canada (upper left) and details of the layout of Seton dam and fishway (bottom right)...............................................................................94 Figure 4.2. The percentage of individuals that successfully entered the fishway, called the attraction efficiency, and the mean delay (± S.E.) below the dam before entering for sockeye salmon at the Seton Dam in British Columbia, Canada.......................................95 Figure 5.1. Map of Seton-Anderson watershed showing locations of telemetry receivers (numbers), spawning channel and some hydroelectric facilities.....................................119 Figure 5.2. Map of the lower Seton River and surrounding area showing location of 4 sites (letters) where telemetered sockeye salmon were released after tagging................120 Figure 5.3. Water temperature at various depths in Seton and Anderson lakes in 2007. Temperature was measured hourly at numbered receiver stations (see Figure 5.1) and values are means from August 16 – September 5............................................................121 Figure 5.4. Box plots of temperature experience of 24 fish while migrating through Seton Lake, Portage Creek and Anderson Lake........................................................................122 Figure 5.5. Thermal history of 3 exemplar sockeye salmon during migration in the Seton-Anderson watershed in British Columbia, Canada................................................123 Figure 5.6. Plots of significant relationships between in-lake travel speed and temperature experience, and gross somatic energy and hormones of adult sockeye salmon migrating through lakes near spawning areas..................................................................124  vi  ACKNOWLEDGEMENTS Thanks to Scott Hinch for support and guidance throughout this degree and for providing the opportunity to carry out exciting research. Thanks to my parents for continuing to support me in a number ways and encouraging me in everything I do. Thanks to Jessica for emotional support, patience, love, and understanding. I thank Steven Cooke and David Patterson for their input and guidance at all stages of this research. John Richardson also provided very helpful comments as a committee member. Thanks to my lab-mates for valuable feedback, peer support and good company. A number of people helped carry out field and lab work for this research. Andrew Lotto was instrumental in planning logistics and conducting fieldwork. Marika Gale and Ken Jeffries helped with fieldwork. I thank Northern St’at’imc Fisheries for help with logistics and field assistance, particularly Bonnie Adolph, Elijah Michel and Terry Adolph. Thanks also to Harry and Lance O’Donaghey of N’quatqua First Nation for retrieving transmitters and data loggers on spawning grounds. The Canadian Department of Fisheries and Ocean’s Fraser River Environmental Watch Program played a key role in this research, by conducting physiological assays, assisting with fieldwork and providing additional temperature data. In particular, I thank David Patterson, Jayme Hills, D’Arcy McKay, Vanessa Ives, Taylor Nettles and Merran Hague. The field study in this thesis was funded by BC Hydro’s Bridge-Coastal Restoration Program with additional funds from a NSERC Strategic and Discovery grants to Scott Hinch. I also thank Craig Orr and the Watershed Watch Salmon Society for contributing funds to this project. I was supported financially during my studies with a NSERC postgraduate scholarship and additional funding from the Faculty of Forestry and BC Hydro – thanks.  vii  CO-AUTHORSHIP STATEMENT I held primary responsibility for all field work, data analyses and writing manuscripts. Acknowledgement of co-authors in chapters 2-5 reflects their contribution to the studies as follows: Chapter 2: S. Hinch helped conceptualize the study and contributed to preparation of the manuscript. A version of this chapter has been accepted for publication and is ‘in press’ in Fish and Fisheries. Chapter 3: S. Hinch, S. Cooke and D. Patterson helped design the study and contributed to interpretation and preparation of the manuscript. A version of this chapter has been submitted for publication. Chapter 4: S. Hinch helped design the study and contributed to interpretation and preparation of the manuscript. Chapter 5: S. Hinch, S. Cooke and D. Patterson helped design the study and contributed to interpretation and preparation of the manuscript. A version of this chapter has been submitted for publication.  viii  CHAPTER 1: Introduction General introduction and background Migration has been described as the persistent and directed movement of an organism between habitats, with energy specifically allocated to these movements, often with a subsequent return journey (Dingle, 1996). A well-known example illustrating all of these elements is provided by the life-histories of anadromous Pacific salmon (Oncorhynchus spp.). Pacific salmon are born in freshwater streams or lakes but migrate to the ocean to feed and grow, presumably taking advantage of the higher productivity in the ocean environment (Gross et al., 1988). After a variable amount of time at sea, depending on species, individuals migrate back into freshwater, returning to spawn in their natal stream, a process referred to as ‘homing’. Long distance migrations are a costly and risky endeavour (Dingle, 1996). The spawning migrations of Pacific salmon returning to natal streams pose a number of physiological and energetic challenges to migrants (Hinch et al., 2006). Salmon must remodel their osmoregulatory systems in order to maintain homeostasis while moving from saltwater to freshwater environments (Clarke and Hirano, 1995; Shrimpton et al., 2005). Entry into the river is also associated with introduction to a suite of freshwater parasites (Macdonald et al., 2000; Jones et al., 2003), which are a major cause of pre-spawn and en route mortality (Gilhousen, 1990). Migrants travel long distances (over 1000 km from the river mouth in many cases), may ascend considerable elevations, and in some cases must swim through constricted areas with turbulent and fast flows that are difficult to pass (Ricker 1987; Hinch and Bratty, 2000). Because salmon cease feeding prior to entering the river and die after reproducing, all migration and spawning activities are fuelled using only stored energy reserves. During the course of this journey, salmon are simultaneously undergoing endocrinological and morphological changes associated with reproductive development and maturation. Clearly, spawning migrations are a challenging phase of salmon life-history and consequently many individuals die before reaching spawning areas (Quinn, 2005).  1  Environmental conditions have large influence on the migration biology of Pacific salmon (Macdonald, 2000; Quinn, 2005). Water temperature is known to be particularly important, as it regulates many aspects of migration including rates of travel (Goniea et al., 2006; Crossin et al., 2008; Keefer et al., 2008), physiological condition (Hinch et al., 2006; Crossin et al., 2008) and en route mortality (Gilhousen, 1990; Macdonald et al., 2000; Keefer et al. 2008). Given the importance of temperature it is not surprising that salmon are known to behaviourally thermoregulate. For instance, a study of sockeye salmon in Lake Washington found that fish spent the majority of their time in the hypolimnion at 9-11˚C, rarely occupying warmer or cooler areas (Newell and Quinn, 2005). Adult migrating Weaver Creek sockeye (Fraser River, BC) which entered the Fraser River during peak summer temperatures and volitionally occupied the hypolimnion of a lake upstream of spawning grounds had much higher survival than those that held in the river prior to spawning (Mathes et al., in press). However, previous research has only documented the existence of behavioural thermoregulation and no studies have examined physiological factors that underlie individual variation in thermal behaviour. Human activities have added further challenges to the migrations of adult Pacific salmon. For instance, migrants may be caught by a number of fisheries including those of commercial, recreational or subsistence sectors in the marine, coastal or river environment. Climate change due at least in part to humans has and will continue to alter environmental conditions that migrants encounter (Morrison et al., 2002; Ferrari et al., 2007). Because Pacific salmon populations migrate at precise times across years (Groot and Margolis, 1991), and are adapted to conditions during these times (Hodgson and Quinn, 2002), migration during abnormal temperatures or flow conditions result in high levels of mortality (Macdonald 2000; Cooke et al., 2004; Farrell et al., 2008). Perhaps the single greatest impact to many rivers has been the construction of large dams for water storage, diversion or hydroelectric generation (Dynesius and Nilsson, 1994; Nilsson et al., 2005). Dams have a number of detrimental effects on aquatic ecosystems, including altered hydrology, temperature regimes, and flow of  2  sediment and nutrients (Richter et al., 1997). However, the most notable effect of dams on fish migrations is that they restrict or prevent the movements to upstream habitats. At many dams, fishways or other passage facilities have been constructed to enable fish to move past the barrier (Clay, 1995). However, a growing body of literature suggests that fishways do not always perform as well as anticipated (Castro-Santos, 2009). A proportion of fish within a population may fail to pass a fishway (Bunt et al., 2000; Karpinnen et al., 2002; Aarestrup et al., 2003) and certain species may be unable to pass at all (Schwalme et al., 1985; Mallen-Cooper and Brand, 2007). Even fish that successfully pass a fishway may first suffer long delays (Laine et al., 2002; Thorstad et al., 2003; Naughton et al., 2005). In order to mitigate the impacts of barriers on fish populations, fishways need to permit safe passage without delays that are likely associated with fitness costs (Castro-Santos et al., 2009). Most previous studies evaluating fishway performance document usage by certain species or quantify the proportion of individuals in a population that pass a fishway, termed the passage efficiency (e.g. Bunt et al., 1999). A number of studies have assessed how environmental factors such as discharge (Bunt et al., 2001; Naughton et al., 2007), or structural features, such as the size or location of the entrance (Bunt, 2001; Baumgartner and Harris, 2007), affect passage. However, the vast majority of studies evaluating fishway effectiveness do not consider post-passage effects or monitor behaviour and survival after passage (Roscoe and Hinch, 2009). Such information is necessary to ensure dams and fishways do not continue to have deleterious effects on fish populations. There is a growing body of research examining physiological or energetic variables underlying behaviour and mortality of migrating Pacific salmon (reviewed in Hinch et al., 2006). Of all species of Pacific salmon, sockeye salmon (Oncorhynchus nerka) have been studied the most and have often been used as model species. For instance, Fraser River sockeye salmon that entered the river abnormally early in the year had lower levels of somatic energy and were more reproductively advanced compared to fish that entered later in the year (Cooke et al., 2006a). Faster rates of up-river travel are  3  also correlated with low levels of energy (Hanson et al., 2008) and more advanced reproductive status (Crossin et al., 2008). Several studies have linked physiological status at capture to subsequent fate. Fish that die before reaching spawning areas often exhibit indicators of stress (e.g. elevated plasma cortisol, glucose, and lactate; Cooke et al., 2006b), low levels of energy and advanced reproductive status (Cooke et al., 2006a; Young et al., 2006) compared to fish that successfully reached spawning grounds. Thus, the use of non-lethal physiological biopsies combined with telemetry to track behaviour and fate has emerged as a powerful approach to better understand migration biology and address conservation issues concerning Pacific salmon (Cooke et al., 2005; Cooke et al., 2008). Physiological tools also show great promise for evaluating and mitigating the consequences of fishways and other hydropower infrastructure on fish (Hasler et al., 2009). For instance, electromyogram telemetry has been used to document energy use of anadromous salmon during passage through dam tailraces and fishways (Gowans et al., 2003; Brown et al., 2006; Enders et al., 2008; Pon et al., 2009a). Research on sockeye salmon in the Seton River, a tributary of the Fraser River, British Columbia, found that indices of physiological stress (i.e. plasma cortisol, metabolites, and ions) measured after fishway ascent did not differ among periods of different water discharge volumes from the dam (Pon et al., 2009b), but that fish that failed to pass the fishway had higher levels of plasma sodium, suggesting that they were more physiologically stressed than successful fish (Pon et al., 2009a). A study of the reproductive migrations of northern pike (Esox lucius) reported that measures of plasma lactate and glucose were indicative of moderate stress following passage of a Denil-style fishway (Schwalme et al., 1985). However, only a few previous studies evaluating fishway passage have incorporated physiological or energetic analyses, although they are powerful means of assessing consequences of passage and mechanisms of failure.  Thesis overview and objectives This thesis examines behaviour, physiology and fate of sockeye salmon during the final portion of the spawning migration, once they have reached their natal watershed,  4  and the impacts dams and fishways can have on these migrations. There were three main objectives. The first objective was to review the literature in order to assess the way that previous research has scientifically evaluated fishways or other passage facilities. The second objective was to assess the impact of a dam and fishway on migration behaviour and mortality of a population of sockeye salmon. Thirdly, sockeye salmon migrating through large, thermally stratified lakes upstream of a dam were used as a model to investigate the relationship between thermoregulatory behaviour and physiology of individual fish. Here, I briefly summarize how these objectives were achieved and are presented in the subsequent chapters of this thesis. Chapter 2 is a quantitative literature review of studies evaluating the effectiveness of fishways and other passage facilities. The review assesses what taxa and life-stages have been studied, the questions asked during evaluations, and how these varied by time or by geographic region. As such, the review puts into context my field study of the effectiveness of a fishway for sockeye salmon (Chapters 3 and 4), and suggests priorities for future research on fish passage. In Chapter 3, I report the findings of an evaluation of the impact of a dam and fishway on mortality of up-river migrating sockeye salmon in the Seton River, British Columbia. Since previous research at the Seton dam indicated that passage through the dam tailrace and fishway may be difficult and some fish fail to pass (Pon et al., 2009a), the main hypothesis was that the fishway has post-passage consequences that affect subsequent behaviour and survival. I used acoustic telemetry and an experimental approach, releasing some fish upstream of the dam, and transporting and releasing other fish downstream of the fishway, and compared behaviour and mortality between release groups. Non-lethal physiological biopsies were taken from tagged fish at the time of capture to evaluate the effects of handling and transportation, and to aid in interpretation of subsequent behaviour and fate. Chapter 4 assesses the effects of water discharge on fishway entrance and passage behaviour of sockeye salmon at the Seton River Dam. Water velocity and discharge are  5  known to be important cues stimulating upstream migration of salmonids and attraction into fishways. However, the vast majority of fishways have not been evaluated in terms of how operational water discharge levels affect fish passage. The analysis synthesizes data from my study at Seton dam in 2007 with data from a previous telemetry study at this locale (Pon et al., 2009a) in order to assess changes in fishway attraction efficiency and entrance delay across a broad range of water discharges. The goal of this study was to help guide future adaptive management experiments and inform operational procedures at Seton Dam Fishway. In Chapter 5, I investigate the hypothesis that temperatures selected by sockeye salmon while migrating through thermally stratified lakes are related to an individual’s reproductive status and energy reserves. Fish were caught from the Seton Dam Fishway, non-lethally biopsied, fitted with an acoustic telemetry transmitter and archival thermal logger, and tracked through two lakes near spawning areas using a fixed array of telemetry receivers. Levels of reproductive hormones and gross somatic energy were related to temperature experience and other in-lake behaviours (travel rate, circling, and holding). I predicted that fish that were more reproductively advanced and had lower levels of energy would select cooler temperatures and travel faster and more directly compared to less mature fish with high energy levels. This study is the first to examine physiological factors underlying thermoregulatory behaviour in wild adult salmon. In my conclusion (Chapter 6), I synthesize the findings of my studies concerning fishway passage, discuss limitations of my research and suggest implications of the results for fisheries management and future studies of salmon migration.  6  References Aarestrup, K., M.C. Lucas, and J.A. Hansen. 2003. Efficiency of a nature-like bypass channel for sea trout (Salmo trutta) ascending a small Danish stream studied by PIT telemetry. Ecology of Freshwater Fish 12:160-168. Brown, R.S., D.R. Geist, and M.G. Mesa. 2006. Use of electromyogram telemetry to assess swimming activity of adult spring Chinook salmon migrating past a Columbia River dam. Transactions of the American Fisheries Society 135:281-287. Baumgartner, L.J. and J.H. Harris. 2007. Passage of non-salmonid fish through a Deelder lock on a lowland river. River Research and Applications 23:1058-1069. Bunt, C.M. 2001. Fishway entrance modifications enhance fish attraction. Fisheries Management and Ecology 8:95-105. Bunt, C.M., C. Katopodis, and R.S. McKinley. 1999. Attraction and passage efficiency of white suckers and smallmouth bass by two Denil fishways. North American Journal of Fisheries Management 19:793-803. Bunt, C.M., Cooke, S.J. and McKinley, R.S. 2000. Assessment of the Dunnville Fishway for passage of walleyes from Lake Erie to the Grand River, Ontario. Journal of Great Lakes Research 26:482-488. Bunt, C.M., B.T. van Poorten, and L. Wong. 2001. Denil fishway utilization patterns and passage of several warmwater species relative to seasonal, thermal and hydraulic dynamics. Ecology of Freshwater Fish 10:212-219. Castro-Santos, T., A. Cotel, and P.W. Webb. 2009. Fishway evaluations for better bioengineering: An integrative approach. in A. Haro, K.L. Smith, R.A. Rulifson, C. M. Moffit, R.J. Klauda, M. J. Dadswell, R.A. Cunjak, J.E. Cooper, K.L. Beal, and T.S. Avery, editors. Challenges for diadromous fishes in a dynamic global environment. American Fisheries Society Symposium, Bethesda, MD (in press). Clarke, W.C. and T. Hirano. 1995. Osmoregulation. Pages 317-378 in C. Groot, L. Margolis, and W.C. Clarke, editors. Physiological ecology of Pacific salmon. University of British Columbia Press, Vancouver. Clay, C.H. 1995. Design of Fishways and Other Fish Facilities, 2nd edition, Lewis Publishers, Boca Raton. Cooke, S.J., S.G. Hinch, A.P. Farrell, M.F. Lapointe, S.R.M. Jones, J.S. Macdonald, D.A. Patterson, M.C. Healey, and G. Van Der Kraak. 2004. Abnormal migration timing and high en route mortality of sockeye salmon in the Fraser River, British Columbia. Fisheries 29:22-33.  7  Cooke, S.J., G.T. Crossin, D.A. Patterson, K.K. English, S.G. Hinch, J.L. Young, R.F. Alexander, M.C. Healey, G. Van Der Kraak, and A.P. Farrell. 2005. Coupling noninvasive physiological assessments with telemetry to understand inter-individual variation in behaviour and survivorship of sockeye salmon: Development and validation of a technique. Journal of Fish Biology 67:1342-1358. Cooke, S.J., S.G. Hinch, G.T. Crossin, D.A. Patterson, K.K. English, M. Shrimpton, G. Van Der Kraak, and A.P. Farrell. 2006a. Physiology of individual late-run Fraser River sockeye salmon (Oncorhychus nerka) sampled in the ocean correlates with fate during spawning migration. Canadian Journal of Fisheries and Aquatic Sciences 63:1469-1480. Cooke, S.J., S.G. Hinch, G.T. Crossin, D.A. Patterson, K.K. English, M.C. Healey, J.M. Shrimpton, G. Van Der Kraak, and A.P. Farrell. 2006b. Mechanistic basis of individual mortality in Pacific salmon during spawning migrations. Ecology 87:1575-1586. Cooke, S.J., S.G. Hinch, A.P. Farrell, D.A Patterson, K. Miller-Saunders, D.W. Welch, M.R. Donaldson, K.C. Hanson, G.T. Crossin, I. Olsson, M.S. Cooperman, R. Thomson, R. Hourston, K.K. English, S. Larsson, J.M. Shrimpton, and G. Van Der Kraak. 2008. Developing a mechanistic understanding of fish migrations by linking telemetry with physiology, behavior, genomics and experimental biology: An interdisciplinary case study on adult Fraser River sockeye salmon. Fisheries 33:321338. Crossin, G.T., S.G. Hinch, S.J. Cooke, D.W. Welch, D.A. Patterson, S.R.M. Jones, A.G. Lotto, R.A. Leggatt, M.T. Mathes, J.M. Shrimpton, G. Van der Kraak, and A.P. Farrell. 2008. Exposure to high temperature influences the behaviour, physiology, and survival of sockeye salmon during spawning migration. Canadian Journal of Zoology 86:127-140. Dingle, H. 1996. Migration: The biology of life on the move. Oxford University Press, Oxford. Dynesius, M. and C. Nilsson. 1994. Fragmentation and flow regulation of river systems in the northern third the world. Science 206:753:762. Enders, E.C., C.J. Pennell, R.K. Booth, and D.A. Scruton. 2008. Energetics related to upstream migration of Atlantic salmon in vertical slot fishways. Canadian Technical Report of Fisheries and Aquatic Sciences 2800:v+22p. Farrell, A.P., S.G. Hinch, S.J. Cooke, D.A. Patterson, G.T. Crossin, M. Lapointe, and M.T. Mathes. 2008. Pacific salmon in hot water: applying aerobic scope models and biotelemetry to predict the success of spawning migrations. Physiological Biochemistry and Zoology 81:697-708.  8  Ferrari, M.R., J.R. Miller, and G.L. Russell. 2007. Modeling changes in summer temperature of the Fraser River during the next century. Journal of Hydrology 342:336-346. Gilhousen, P. 1990. Prespawning mortalities of sockeye salmon in the Fraser River system and possible causal factors. International Pacific Salmon Fisheries Commission Bulletin 26. Gowans, A.R., J.D. Armstrong, I.G. Priede, and S. Mckelvey. 2003. Movements of Atlantic salmon migrating upstream through a fish-pass complex in Scotland. Ecology of Freshwater Fish 12:177-189. Groot, C. and L. Margolis. 1991. Pacific salmon life histories. Unviersity of British Columbia Press, Vancouver. Gross, M.R., R.M. Coleman, and R.M. McDowall. 1988. Aquatic productivity and the evolution of diadromous fish migration. Science 239:1291-1293. Hanson, K.C., S.J. Cooke, S.G. Hinch, G.T. Crossin, D.A. Patterson, K.K. English, M.R. Donaldson, J.M. Shrimpton, G. Van der Kraak, and A.P. Farrell. 2008. Individual variation in migration speed of upriver-migrating sockeye salmon in the Fraser River in relation to their physiological and energetic status at marine approach. Physiological and Biochemical Zoology 81:255-268. Hasler, C.T., L.B. Pon, D.W. Roscoe, B. Mossop, D.A. Patterson, S.G. Hinch, and S.J. Cooke. 2009. Expanding the “toolbox” for studying the biological responses of individual fish to hydropower infrastructure and operating strategies. Environmental Reviews 17:179-197. Hinch, S.G., and J. Bratty. 2000. Effects of swim speed and activity pattern on success of adult sockeye salmon migration through an area of difficult passage. Transactions of the American Fisheries Society 129:598-606. Hinch, S.G., S.J. Cooke, M.C. Healey, and A.P. Farrell. 2006. Behavioral physiology of fish migrations: Salmon as a model approach. Pages 239-295 in K. Sloman, S. Balshine, and R. Wilson, editors. Fish physiology volume 24: Behavior and physiology of fish. Elsevier Press, New York, NY. Hodgson, S. and T.P. Quinn. 2002. The timing of adult sockeye salmon migration into fresh water: adaptations by populations to prevailing thermal regimes. Canadian Journal of Zoology 80:542-555. Jones S.R.M., G. Prosperi-Porta, S.C. Dawe, and D.P. Barnes. 2003. Distribution, prevalence and severity of Parvicapsula minibicornis infections among anadromous salmonids in the Fraser River, British Columbia, Canada. Diseases of Aquatic Organisms 54:49-54.  9  Karppinen, P., T. Maekinen, J. Erkinaro, V. Kostin, R. Sadkovskij, A. Lupandin, and M. Kaukoranta. 2002. Migratory and route-seeking behaviour of ascending Atlantic salmon in the regulated river Tuloma. Hydrobiologia 483:23-30. Keefer, M.L., C.A. Peery, and M.J. Heinrich. 2008. Temperature-mediated en route migration mortality and travel rates of endangered Snake River sockeye salmon. Ecology of Freshwater Fish 17:136-145. Laine, A., T. Jokivirta, and C. Katopodis. 2002. Atlantic salmon, Salmo salar L., and sea trout, Salmo trutta L., passage in a regulated northern river - fishway efficiency, fish entrance and environmental factors. Fisheries Management and Ecology 9:65-77. Macdonald, J.S. 2000. Mortality during the migration of Fraser River sockeye salmon (Oncorhynchus nerka): A study of the effect of ocean and river environmental conditions in 1997. Canadian Technical Report of Fisheries and Aquatic Sciences 2315. Macdonald, J.S., M.G.G. Foreman, T. Farrell, I.V. Williams, J. Grout, A. Cass, J.C. Woodey, H. Enzenhofer, W.C. Clarke, R. Houtman, E.M. Donaldson, and D. Barnes. 2000. The influence of extreme water temperatures on migrating Fraser River sockeye salmon (Oncorhynchus nerka) during the 1998 spawning season. Canadian Technical Report of Fisheries and Aquatic Sciences 2315:39-57. Mallen-Cooper, M., and D.A. Brand. 2007. Non-salmonids in a salmonid fishway: What do 50 years of data tell us about past and future fish passage? Fisheries Management and Ecology 14:319-332. Mathes, M.T., S.G. Hinch, S.J. Cooke, Crossin, G.T., D.A. Patterson, A.G. Lotto and A.P. Farrell. 2009. Effect of water temperature, timing, physiological condition and lake thermal refugia on migrating adult Weaver Creek sockeye salmon (Oncorhynchus nerka). Canadian Journal of Fisheries and Aquatic Sciences, in press. Morrison, J., M. Quick, and M.G.G. Foreman. 2002. Climate change in the Fraser River watershed: flow and temperature projections. Journal of Hydrology 263: 230-244. Naughton, G.P., C.C. Caudill, M.L. Keefer, T.C. Bjornn, L.C. Stuehrenberg, and C.A. Peery. 2005. Late-season mortality during migration of radio-tagged adult sockeye salmon (Oncorhynchus nerka) in the Columbia River. Canadian Journal of Fisheries and Aquatic Sciences 62:30-47. Naughton, G.P., C.C. Caudill, C.A. Peery, T.S. Clabough, M.A. Jepson, T.C. Bjornn, and L.C. Stuehrenberg. 2007. Experimental evaluation of fishway modifications on the passage behaviour of adult Chinook salmon and steelhead at Lower Granite Dam, Snake River, USA. River Research and Applications 23:99-111.  10  Newell, J.C., and T.P. Quinn. 2005. Behavioral thermoregulation by maturing adult sockeye salmon (Oncorhynchus nerka) in a stratified lake prior to spawning. Canadian Journal of Zoology 83:1232-1239. Nilsson, C., C.A. Reidy, M. Dynesius, and C. Revenga. 2005. Fragmentation and flow regulation of the world’s large river systems. Science 308:405-408. Pon, L.B., S.G. Hinch, S.J. Cooke, D.A. Patterson, and A.P. Farrell. 2009a. Physiological, energetic and behavioural correlates of successful fishway passage of adult sockeye salmon (Oncorhynchus nerka) in the Seton River, British Columbia. Journal of Fish Biology 74:1323-1336. Pon, L.B., S.G. Hinch, S.J. Cooke, D.A. Patterson, and A.P. Farrell. 2009b. A comparison of the physiological condition of migrant adult sockeye salmon and their attraction into the fishway at Seton River dam, British Columbia under three operational water discharge rates. North American Journal of Fisheries Management, in press. Quinn, T.P. 2005. The behavior and ecology of Pacific salmon and trout. University of Washington Press, Seattle. Richter, B.D., D.P. Braun, M.A. Mendelson, L.L. Master. 1997. Threats to imperiled freshwater fauna. Conservation Biology 11:1081-1093. Ricker, W.E. 1987. Effects of the fishery and of obstacles to migration on the abundance of Fraser River sockeye salmon (Oncorhynchus nerka). Canadian Technical Report of Fisheries and Aquatic Sciences 1522. Roscoe, D.W., and S.G. Hinch. 2009. Effectiveness monitoring of fish passage facilities: historical trends, geographic patterns and future directions. Fish and Fisheries, in press. Schwalme, K., W.C. Mackay, and D. Lindner. 1985. Suitability of vertical slot and Denil fishways for passing north-temperate, nonsalmonid fish. Canadian Journal of Fisheries and Aquatic Sciences 42:1815-1822. Shrimpton, J.M., D.A. Patterson, J.G. Richards, S.J. Cooke, P.M. Schulte, S.G. Hinch, and A.P. Farrell. 2005. Ionoregulatory changes in different populations of maturing sockeye salmon (Oncorhynchus nerka) during ocean and river migration. Journal of Experimental Biology 208:4069-4078. Thorstad, E.B., F. Okland, F. Kroglund, and N. Jepsen. 2003. Upstream migration of Atlantic salmon at a power station on the River Nidelva, Southern Norway. Fisheries Management and Ecology 10:139-146.  11  Young, J.L., S.G. Hinch, S.J. Cooke, G.T. Crossin, D.A. Patterson, A.P. Farrell, G. Can Der Kraak, A.G. Lotto, A. Lister, M.C. Healey, and K.K. English. 2006. Physiological and energetic correlates of en route mortality for abnormally early migrating adult sockeye salmon (Oncorhynchus nerka) in the Thompson River, British Columbia. Canadian Journal of Fisheries and Aquatic sciences 63:10671077.  12  CHAPTER 2: Effectiveness monitoring of fish passage facilities: historical trends, geographic patterns, and future directions.1 Introduction Connectivity of watersheds is crucially important to fishes and other aquatic organisms. Fragmentation of aquatic habitat by anthropogenic barriers is frequently associated with extirpation or extinction of fish species (Nehlsen et al., 1991; Slaney et al., 1996; Sheer and Steel, 2006;) and with severe negative consequences at the ecosystem level (Fahrig, 2003; Nilsson et al., 2005; Layman et al., 2007). To enable fish to pass some barriers, various designs of fishways or fish ladders have been developed – these are reviewed elsewhere (Clay, 1995; Odeh, 1999). Where fishways were not or could not be built, fish may be carried over the barrier by elevators (lifts) or locks (Travade and Larinier, 2002), or simply moved around a dam by trap-and-truck operations (Muir et al., 2006). Recently, the use of “nature-like” fishways, which mimic natural side channels, has become popular, particularly in Europe (Parasiewicz et al., 1998). Within the last 50 years fishways and other passage operations, hereafter referred to collectively as fish passage facilities, have become increasingly sophisticated and efficient, their design a product of collaboration between hydraulic engineers and biologists (Odeh, 1999; Castro-Santos et al., 2009). However, despite advances in fish passage technology, a large number of fishways still prevent or delay passage of both target (Bunt et al., 2000; Aarestrup et al., 2003; Naughton et al., 2005; Caudill et al., 2007) and non-target species (Haro and Kynard, 1997; Mallen-Cooper and Brand, 2007; Parsley et al., 2007). Thus, the presence of a fishway alone certainly does not guarantee that the fish are able to surmount the barrier to their movement. The fact that fishways often do not perform as intended points to the need to monitor and evaluate effectiveness after construction, and modify them as needed. Indeed, others have highlighted the need for evaluation of efficiency of fishways after 1  A version of this chapter has been accepted for publication. Roscoe, D.W. and S.G. Hinch. 2009. Effectiveness monitoring of fish passage facilities: historical trends, geographic patterns, and future directions. Fish and Fisheries, in press. 13  installation (Odeh, 1999). But although there is an extensive body of literature concerning passage at fishways, the number of studies is vanishingly small when compared to the thousands of fishways in existence worldwide; the vast majority of fishways or methods of fish transfer have never been evaluated. For instance, a survey of non-federal hydroelectric projects in the United States found that only 34 of 280 projects had measures in place to allow upstream passage, and more than half of these had not been evaluated (Cada, 1998). Among fishways that have been studied, the approach and evaluation criteria vary widely, but the type of evaluation should ultimately depend on the goals and purpose of the facility. To effectively evaluate fishway performance, studies should directly address clearly defined passage objectives. These vary among countries. The European Water Directive Framework considers free passage and undisturbed migration of fish as a key component to restoring and managing watersheds (European Commission, 2000; Weyand et al., 2005). In the United States, hydropower licensing requires that fishways ensure safe and timely movement of fish past hydropower projects (Odeh, 1999). The ultimate goal for habitat compensation programs in Canada has been termed No Net Loss (NNL), where restoration efforts legally must result in no decrease in fish producing capacity (Quigley and Harper, 2006). In the case of fish passage at barriers, to achieve NNL a fishway would need to not just allow passage of target species, but allow unhindered passage of all life-stages of all species without subsequent effects on reproductive success. A recently proposed concept for the objective of passage facilities is the idea of ‘transparency’ of the dammed reach to the movements of native species (Castro-Santos et al., 2009). A ‘transparent’ fishway would allow entry and up- or down-stream passage of the fish without delay, energetic costs, stress, disease, injury or other fitness associated costs. Thus, one concept in common between the ‘transparency’ principle and NNL criteria is that passage occurs while minimizing fitness costs, which is ultimately what is important in order to mitigate the effects of barriers on fish populations. Although transparency, or passage with zero effects on reproductive success (i.e. fitness) are useful conceptual objectives, these goals may not always be achievable under  14  economic and biological constraints, and fitness is typically not easy to quantify in field studies. Instead, monitoring and evaluation of restoration efforts, often called effectiveness monitoring, at fish passage facilities has typically focused on simpler measures of performance. The most basic studies simply observe which species successfully use a fishway. Mark-and-recapture or telemetry tools are often used to estimate proportions of fish passing a facility (e.g. Bunt et al., 1999; Pompeu and Martinez, 2007). Many studies have attempted to characterize how environmental factors affect fish passage. Given the diversity of facility designs, evaluation criteria and sitespecific issues, the results from many studies are difficult to apply to other passage facilities. Furthermore, when planning effectiveness monitoring it can be difficult to identify relevant study questions and evaluation criteria. Therefore, it would be useful to characterize what types of effectiveness monitoring have been done, what findings are applicable across sites, and what knowledge gaps remain regarding passage at fishways. Since expansion of hydroelectric power generation is likely to create even more barriers in waterways in the near future (Demirbas, 2007; Yuksel, 2007), there may be an even greater need to provide safe, effective passage for fishes. Indeed, with many freshwater and diadromous fish stocks in peril, and large scale perturbations such as climate change continuing to threaten fish populations (Xenopoulos et al., 2005; Brander, 2007), unhindered fish passage at barriers may be crucially important to the conservation of freshwater ecosystems. It is, however, important to note that the barrier effect is only one of many impacts of dams on fishes. Dams can significantly alter up- and downstream habitats and so unhindered passage at barriers does not ensure pre-barrier fish abundances or biodiversity if surrounding habitats are no longer suitable. Nonetheless, connectivity of river corridors has been identified as a prerequisite to good ecological condition in managed watersheds (Weyand et al., 2005). Although there have been previous summaries of design and technical considerations for fishways (Clay, 1995; Odeh, 1999; Larinier, 2002), this is the first review of how passage facilities have been scientifically evaluated. First, we reviewed and categorized literature concerning evaluation of fish passage facilities to identify the  15  major questions addressed, and the taxa and life-stages studied. Second, we analyzed trends in fish passage publications to evaluate whether the number of studies conducted and the focus of research changed over time, or varied by geographic region. Lastly, knowledge gaps in the evaluation of fish passage facilities are discussed in terms of how they are limiting our ability to adequately monitor and manage fish resources and what future research steps may be needed.  Methods We conducted a literature search for peer-reviewed journal articles pertaining directly to evaluations of fish movements past dedicated fish passage facilities (passage at culverts or natural obstructions are not included). Review articles that included new fishway evaluation data and modelling or experimental studies that specifically evaluated a real passage facility were also included. Although many evaluations of fish passage facilities are published only in government or technical reports, our search was limited to peer-review journals for two reasons. First, studies published in scientific journals are more likely to be broadly framed in terms of biological responses, and are therefore more likely to be applicable across sites. Second, these articles represent the body of knowledge that is widely available to researchers, whereas technical reports may not be readily available to the public. The literature search was conducted using two commercial academic search engines, ISI Web of Knowledge and Aquatic Sciences and Fisheries Abstracts (ASFA), and combinations of the search terms “fishway”, “fishpass”, “fish bypass”, “fish”, “dam” and “passage”. These keywords were chosen to encompass both up- and down-stream passage. The search included articles as early as was covered by the databases (from 1965 but with some earlier records) up to June of 2008. All articles that met the criteria were entered into a database, and categorized in terms of fish taxa (order) and life-stage studied, geographic location and general type of research questions (Table 2.1). Initially, we evaluated three types of research questions: (1) efficiency questions quantified the proportion of individuals able to pass a fishway, or qualitatively assessed which species in a community were able to pass; (2) mechanism questions examined factors that affected passage, such as environmental variables, physical structures or behaviours expressed during passage; and (3) consequences  16  questions quantified post-passage effects on individual fish. To analyze temporal and regional trends in the way fishways are evaluated, we used Chi-square contingency analysis to compare the frequency of research questions, life-stages, and taxa studied among time periods and geographic locations. For comparisons in which expected values of a category were less than five, Fisher’s exact test was used instead of a Chi-square test. A significance level of 0.05 was used - Bonferroni corrections were made when there were multiple comparisons. During the review process, we discovered a very small but unique set of papers that examined physiological aspects of passage which involved questions of efficiency, mechanism and consequence. We thus created a fourth research question category, physiology, to be used in our analyses which involved questions of ‘endogenous’ issues such as physiological stress, ionoregulation and reproductive state. There was some inherent overlap between physiology questions and both mechanism and consequences questions but because there were so few studies involved, we could not create additional sub-categories for analyses. We discuss how the inclusion of this new category may have affected our broader analyses and interpretations.  Results The literature search identified 96 articles reporting on evaluations of fish passage facilities (Table 2.2). Salmoniformes was the most studied order of fish. Fifty-eight percent of studies included salmonids and 45% of studies concerned salmonids exclusively. Non-salmonid orders were included in 55% of studies, and 30% of studies concerned the entire local fish community. In terms of life-stages studied, 68% of articles studied adults, 17% studied juveniles, and 16% studied more than one life-stage. Categorization of articles in terms of research questions revealed that 97% of articles studied efficiency, 72% of articles studied a mechanism of passage or failure, 14% of articles studied consequences of passage and 7% of articles studied physiology. The number of articles published on the evaluation of fishways increased over time (Figure 2.1). Seventy-six percent of articles were published in the last ten years  17  (1999-2008), and 20% of all studies were in 2007 alone. To assess whether the way fishways have been evaluated has changed over time we used Chi-square and Fisher’s Exact tests to compare the frequency that different taxa, life-stages, and general research questions were studied among the following six time periods: 1960-1979, 1980-1989, 1990-1994, 1995-1999, 2000-2004, 2005-2008. These time periods did not differ significantly in the percentage of studies that included salmonids, non-salmonids or the entire local fish community (P=0.59, P=0.48 and P=0.30, respectively). Life-stage studied, which could be adults, juveniles or more than one life-stage, did not differ significantly among time periods (P=0.71). The frequency of mechanism, consequences, and physiology questions was not different among time periods (all P > 0.05; Figure 2.2). However, the frequency of efficiency questions was not equal among all six time periods (P=0.0018). All but one of the studies from the latest five time periods included efficiency questions but 50% of the four studies from the earliest time period (19601979) did not (Figure 2.2). Thus, in general, the way that fishway evaluations were studied did not change significantly over time. To analyze regional trends in fishway evaluations, the studies were divided into three groups based on geographic location: North America, Europe, Australia/South America. Although there are fish passage facilities in other parts of the world not represented by these three groups, our search did not uncover peer-reviewed articles evaluating passage facilities in other locations. A worldwide summary of fishways is given by Clay (1995). Table 2.3 summarizes the classification of passage facility evaluations by geographic location. There were significant differences in fishway evaluations among geographic locations. Of the total number of studies, 52% were from North America, 30% were from Europe and 18% were from South America or Australia. Not surprisingly, the taxa studied varied by geographic location. Of the 50 articles from North America, 66% included salmonids and 60% studied only salmonids. A majority of the studies were from the North-Western United States (n=33), and of these 88% concerned salmonids. Other taxa studied in the Northwest included Petromyzontiformes (n=3), Clupeiformes  18  (n=2), Cypriniformes (n=1) and Scorpaeniformes (n=1). Most of the non-salmonid studies were from the East coast of the United States, where Clupeiformes was the most studied order (78% of 9 studies). Salmoniformes was also the focus of European fishway evaluations and was included in 79% of studies, being the only taxa studied in 45% of reports. The frequency of studies including salmonids was not different between North America and Europe (P=0.30). However, European articles studied the entire fish community more often (39%) than did North American studies (4%; P=0.0002). The most commonly studied non-salmonid orders in Europe were Cypriniformes (n=11) and Perciformes (n=6). Studies from South America and Australia studied the entire community more often than did European studies (P=0.0002). In fact, all but one of the articles from South America and Australia evaluated passage by the entire fish community (Table 2.3). In South America, articles focused mostly on migratory fishes of the orders Siluriformes and Characiformes. Australian studies covered diverse fish taxa including Cypriniformes, Osmeriformes, Perciformes and Clupeiformes, as well as some other aquatic organisms such as crustaceans. The frequency of studies dealing with different life-stages was not equal among geographic locations (P=0.0009; Table 2.3). In particular, life-stages studied in North American articles were significantly different from those from both Europe (P=0.03), and South America and Australia (P=0.0003). In North America, 66% of articles studied adult passage, 28% studied juveniles and 6% studied both. Most articles in Europe evaluated only adult passage (76%) and fewer papers considered more than one life stage (17%) or juvenile passage alone (7%). In South America and Australia, adult life-stages were studied in 59% of articles, 41% studied more than one life-stage and no articles studied juvenile life-stages exclusively. Research questions addressed also differed by geographic region. Nearly all studies included efficiency questions (Table 2.3), and the frequency of studies including this question did not differ by region (P=0.69). One of the main regional differences was that North American studies included mechanism questions (90%) more often than studies from Europe (55%; P=0.0004) or South America and Australia (47%; P=0.0006).  19  In North America, consequences questions were studied in 22% of studies whereas physiology was studied in 12 % of studies. In comparison, consequences and physiology questions were each included in 3% of studies from Europe with one study including both questions. Six percent of studies from South American and Australian studies included a consequences question and no studies examined physiology. Although the trend was that there were more physiology and consequences questions in North America compared to the other two regions, the difference among regions was not statistically significant for physiology (P=0.24) and marginally significant for consequences (P=0.048), perhaps due to small sample sizes and the conservative nature of Fisher’s exact test.  Discussion Our analysis indicates that the number of peer-reviewed articles evaluating fishways and other passage facilities has increased over time, but that articles have not changed significantly over the last 50 years in terms of life-stage, taxa and research questions studied. The evaluation of passage facilities did vary significantly by geographic region. More than half (52%) of all articles uncovered by our search were from North America, 30% of studies were from Europe and 18% were from South America or Australia. However, all but one of the studies from tropical areas were published within the last 10 years. In South America 7 of 9 were published in the last 2 years. This suggests the conclusion that the study of fishway passage is a growing area of research. Salmonids were the most studied taxa in North America and Europe, but in both regions, a large number of articles examined non-salmonid orders (40% and 55% of studies from North America and Europe, respectively) suggesting that the scope of fishway passage evaluations in northern temperate areas extends beyond salmonids to include a wide range fish species. Several authors have pointed out the importance of providing passage to a range of species, including small fishes and those previously considered non-migratory (Eberstaller et al., 1998; Odeh, 1999; Bunt et al., 2001; Stuart et al., 2008). One regional difference in terms of taxa studied was that the entire local fish community was studied rarely in North America (4%), more often in Europe (38%),  20  and in nearly all reported studies (94%) from tropical locations. The broader taxonomic scope of individual articles in Europe compared to North America may have been related to the goals of evaluations and the research questions addressed. In North America, 90% of articles studied mechanism questions whereas in Europe only 55% studied this aspect. Mechanistic understanding of passage failure requires information about individual behaviours and responses to environmental variables. It may be that it is not logistically feasible to gather this type of information for several different taxa within a study. Thus, evaluations in Europe studied baseline efficiencies for a larger range of fish taxa instead of more detailed mechanisms of passage by a single species. Indeed, a key objective of the European Water Directive Framework (European Commission, 2000) is to allow passage of all fish species and other aquatic organisms (Weyand, 2005). Similarly, studies from tropical areas rarely monitored individual passage or mechanisms of failure but nearly always included the entire community. In South America the focus of passage facilities was on large-bodied migratory species that support valuable commercial and recreational fisheries (Agostinho et al., 2002) although most evaluations also considered a wide range of species including small fishes. Passage projects in Australia, on the other hand, had holistic objectives, and aimed to optimize passage for all fish species (Barrett and Mallen-Cooper, 2006). It is worth noting that biodiversity is much greater in tropical regions compared to temperate regions (Kendall and Haedrich 2006; Behrens and Lafferty, 2007), and the broader taxonomic scope in the tropics may be explained in part by the greater number of fish species there. However, at all latitudes fishway passage has been studied for only a small fraction of fish species. Regardless of the number of species in a particular location, articles from tropical areas more often studied a greater number of species within a single study, compared to research from North America. The popularity of nature-like fishways in Europe may also reflect the broad ecosystem level goals of passage facilities there. Nature-like fishways provide a route around a barrier that attempts to mimic in form and function a natural side-channel of the river (Parasiewicz et al., 1998). In contrast to traditional designs, nature-like fishways are made of natural material, are usually longer with more gradual slopes and provide habitat for small fish species or juveniles (Parasiewicz et al., 1998; Larinier 2002).  21  Although many evaluations of nature-like fishways have reported passage by both salmonid and non-salmonid species, as well as habitat usage for juveniles and overwintering, many studies also report problems similar to those common for traditional fishways, such as poor attraction and inappropriate location of entrances (Schmutz et al., 1998; Calles and Greenberg, 2005). In contrast, Aarestrup et al. (2003) found that attraction efficiency was high but passage efficiency was low for sea trout (Salmo trutta, Salmonidae) in a nature-like fishway, a finding attributed to the length and low discharge of the channel. Although nature-like fishways have great potential for passing a broad range of fish species and providing habitat for small fishes and other aquatic organisms, it seems that rigorous site-specific evaluations will be required, as is the case for traditional fishway designs (Calles and Greenberg, 2007). Adults were the most commonly studied life-stage in all three geographic regions. This could be related to the fact that most passage facilities, including fishways, lifts, and locks, are generally designed to accommodate only upstream passage (Odeh, 1999; Schilt, 2007), and are mostly aimed at salmonids. Adult passage bias in passage facilities may have emerged because it was believed that downstream migrating juvenile salmonids can pass through turbines, although with some level of mortality depending on facility specific design and operation, whereas adults cannot pass upstream through them. However, in North America, especially in the Columbia and Snake rivers, there has been a great deal of research concerning downstream passage of juvenile Pacific salmon (Oncorhynchus spp., Salmonidae) and hydro-system related juvenile mortality is an important management issue (Schilt, 2007). Despite this fact, adults were the focus of more than twice as many articles as juveniles in North America (66% vs. 28%). It may be that juveniles are actually much less often studied than adults in North America but another possibility is that evaluations of juvenile passage are less likely to be published in peer-reviewed journals and are therefore under-represented in this review. For example, in a recent review of surface flow outlets designed for safe downstream passage of fish, only 6 of the 69 facilities reviewed were from peer-reviewed articles whereas data from the remaining facilities was obtained from reports, book chapters or personal communications (Johnson and Dauble, 2006). This illustrates how juvenile passage  22  evaluations are often not published in widely available sources although we cannot comment on whether the proportion of studies that are published in peer-reviewed journals differs between adult and juvenile studies in North America. Only two articles (7%) focused exclusively on juvenile passage in Europe. Despite the large interest in anadromous salmonids, few articles examined downstream migration to sea by juveniles, especially compared to the large body of literature on the subject in North America. Surface bypass structures used in combination with sensory stimuli have been evaluated for passage of salmon juveniles in France (Larinier and Boyer-Bernard, 1991a,b). Arnekleiv et al. (2007) found that brown trout (Salmo trutta, Salmonidae) smolts mostly passed through surface spillways at a Norwegian hydroelectric dam. No other articles regarding juvenile fish studied actual efficiency or behaviour and instead only documented usage of fishway by juveniles in addition to other life stages. In South America many fishes have a complex life history that is uncommon elsewhere in the world, and makes them particularly vulnerable to dams and large impoundments. Many species of potamodromous fishes make long-distance upstream migrations to habitats suitable for reproduction and the development of young. After spawning, adults return downstream and eggs develop into larvae as river currents carry them downstream. Larvae drift into marginal lagoons and backwaters, and juveniles remain in these habitats for 1-2 years before recruiting to the adult population. Dams and reservoirs can affect these migratory fishes by blocking upstream reproductive migrations of adults, preventing the downstream migration of spent adults and by preventing larvae from reaching suitable nursery habitat. Although 41% of papers from South America and Australia included more than one life stage, evaluations simply documented passage by different size classes and lifestages. No studies quantified passage efficiency for juveniles or other immature lifestages. In South America, passage of planktonic eggs and larvae through reservoirs and dams poses a unique challenge that is not taken into account by current designs of fish  23  passage facilities (Agostinho et al., 2002). Agostinho et al. (2007a) found that eggs and larvae from migratory fish spawning in upper-basins did not reach lower ends of the reservoir or the fish ladder, probably because they settle out or are intensely predated upon in the reservoir. Because larvae of upper-basin spawners do not contribute to downstream adult recruitment, and spent adults do not readily return downstream after spawning, some passage facilities in Brazil function as primarily one-way routes (Agostinho et al., 2007a). In some watersheds adults readily pass upstream of fishways, upstream larvae do not contribute to downstream recruitment, and suitable nursery habitats exist downstream of a dam but not upstream. In these cases, passage facilities may act as “ecological traps” that do more harm to fish populations than good (Pelicice and Agostinho, 2008). The potential for unforeseen consequences of fish passage is relevant and should be considered in other parts of the world. More studies concerning downstream passage of planktonic and juvenile stages are needed to determine how fishways may prevent recruitment into downstream adult populations (Agostinho et al., 2007a). However, it is important to note that the construction of large dams and impoundments, particularly in vulnerable areas such as floodplains, may create intractable problems that fish passage structures and other watershed management solutions cannot solve. When assessing the types of questions that fishway research addressed we found that nearly all studies included efficiency questions. In the present review, efficiency questions included quantifications of passage efficiency, defined as the species-specific percentage of fish that are able to pass fishway, and observations of the abundance or species composition of fish that passed a facility. The qualitative assessment of the ability of a fishway to pass target species has been called ‘effectiveness’, in contrast to ‘efficiency’ (Larinier, 2001). Many studies from Europe consisted of observations of abundance and species composition of fish utilizing a fishway (Laine et al., 1998; Santos et al., 2002; Epler et al., 2004; Santos et al., 2005; Kotusz et al., 2006; Prchalova et al., 2006) and few studies quantified passage efficiency (but see Gowans et al., 1999; Aarestrup et al., 2003). None of the studies from South America or Australia quantified passage efficiencies and most evaluations simply documented fishway usage by different  24  species and size classes by trapping fish within the fishway. Although documenting effectiveness for various species is an important part of fishway evaluations, quantification of passage efficiency is necessary to evaluate whether fishways have deleterious effects on fish populations, and efficiency alone does not take into account length of delays or fitness costs. Studies framed in terms of ‘transparency’ of a fishway can link together effectiveness and efficiency along with measures such as delay and passage rates in order to broadly assess passage through a facility (Castro-Santos et al., 2009) although this recent framework has not yet been widely used in evaluations. When calculating passage efficiencies, one important consideration suggested by several articles was the interaction between life history, migration motivation and passage. For semelparous anadromous fishes homing to spawning sites upstream of a dam, calculating passage efficiency is straightforward. Fish are highly motivated to pass through a fishway and those that do not pass die before reproducing. However, for other life histories the situation is less clear. Fishway use varies greatly for potamodromous fishes between seasonal spawning migrations and other times of the year (e.g. Bunt et al., 1999). Migration cues and optimal passage conditions may vary depending on life-stage or season (Baras et al., 1994). But clearly ‘motivation’ cannot be directly measured and it is generally not known how it might affect passage efficiency. In some cases suitable spawning or other habitat is available both up- and down-stream of a barrier which can make it difficult to determine if fishes attempted but failed to pass the fishway or found suitable habitat downstream (Linlokken, 1993; Baras et al., 1994; Schmutz et al., 1998; Calles and Greenberg, 2005, 2007). Quantifying the number and rate of approaches towards the fishway entrance can help discern motivation to move upstream past a barrier (e.g. Schmutz et al., 1998) and biotelemetry can be a useful tool to monitor approaches, passage attempts or other fine-scale behaviour (Cooke et al., 2004a). When interpreted in the context of a life history these data help to understand the effect of fishways on fish movements. Studies from North America included mechanism questions more often (90%) than those from Europe (55%) or South America and Australia (47%). In our analysis,  25  mechanism questions referred to examinations of how exogenous, non-physiological factors affected fish passage. Exogenous factors included environmental variables, manmade structures in and around the passage facility and behaviours expressed in response to these variables. A number of articles reviewed here were categorized as including a mechanism question because they quantified different components of fishway passage, in addition to the proportion of fish that are able to move through an entire passage facility (i.e. total passage efficiency). Odeh (1999) proposed three sequential components of fishway passage relevant to both up- and down-stream migrations: attraction, passage itself, and post-passage effects. Castro-Santos et al. (2009) suggest that fishway entrance (i.e. attraction) is a two-step process, consisting of guidance to the fishway entrance and actual entry into the fishway. Indeed, this distinction may be important, as some studies have reported fish approaching the entrance but failing to actually enter (Moser et al., 2002a; Naughton et al., 2007). Since guidance, attraction, or passage can independently limit fishway efficiency, evaluating these different components of passage is necessary to understand mechanisms of passage failure, and identify potential mitigation measures. Although studies from South America and Australia did not calculate speciesspecific guidance, attraction and passage efficiencies, some studies did assess effectiveness of different components of passage by trapping fish in different areas around the fishway (e.g. downstream of dam, fishway entrance, fishway exit, upstream of dam) and comparing species composition and abundances (Stuart and Mallen-Cooper, 1999; Agostinho et al., 2007b; Baumgartner and Harris, 2007; Mallen-Cooper and Brand, 2007; Oldani et al., 2007; Stuart et al., 2007; Stuart et al., 2008). In this way, studies attempt to discern which species can locate the entrance, and those that are able to ascend the fishway itself, without monitoring individual behaviour and passage success. However, interpreting results from fish that were not individually marked and are of unknown origin has the potential to be misleading, and could lead to inappropriate management practices. For example, fish caught in a trap in or near a fishway may have arrived from an upstream location. High densities of fish caught at one location may be used to identify a problematic locale but actually represent a refuge. Therefore, caution  26  should be used when interpreting evaluations based on trapping alone, and more precise methods should be used whenever possible. Studies that included mechanism questions frequently examined associations between passage and environmental variables such as temperature, discharge, or water velocities. Although these types of observations can be useful to identify conditions conducive to passage at a particular site, they do not imply cause and effect and are not necessarily applicable across facilities. Furthermore, many studies report mean values or ranges of conditions rather than including environmental factors as time-dependent covariates. When dam infrastructure and operations permit, adaptive management experiments involving the manipulation of hydraulic parameters, such as velocities, discharge and attraction flow, may be particularly useful to identify efficient passage conditions. If behavioural responses to hydraulic conditions are monitored with technologies such as telemetry or videography, then results may also provide general insights into how fishes respond to different flow characteristics. This approach has been used on the Columbia River in the North-Western United States (Moser et al., 2002a; Reischel and Bjornn, 2003; Naughton et al., 2007), as well as in Eastern North America (Haro and Kynard, 1997) where fish passage has been compared across different water discharges, velocities, entrance modifications or bypass structures. Survival analysis methods are well suited to fish passage studies and should be used when possible since they explicitly consider the effects of environmental co-variates that change over time (Castro-Santos and Haro, 2003; Caudill et al., 2007). Although each passage facility is unique, all fishways must dissipate energy of the water (Clay, 1995) and detailed reporting of hydraulic and structural parameters will help make studies more comparable across sites. Articles from South America and Australia were pooled in this analysis because they were similar in many respects concerning fishway passage. However, one aspect that differed between studies from these regions was the frequency of mechanism questions. Although 47% of tropical studies included a mechanism question, six of these were from Australia, whereas only two were from South America. Most of these studies related the  27  abundance and species composition of fish in the fishway to environmental variables, such as discharge, dissolved oxygen or water temperature (Morgan and Beatty, 2006; Stuart et al., 2007; Stuart et al., 2008), or structural variables, such as fishway slope (Mallen-Cooper and Stuart, 2007) or width of vertical slots (Stuart and Mallen-Cooper, 1999). None of the studies monitored individual behaviours under different conditions. Therefore, in South America, there appears to be a need to incorporate a more mechanistic understanding of passage failure, whereas in Australia several studies have examined environmental and structural variables but studies of biological responses are lacking. Although basic studies of swimming abilities and hydrodynamic cues used by tropical fish are needed for the conservation of South American fishes, Oldani et al. (2007) suggested that few studies have been carried out (but see Santos et al., 2007). The fact that only 14% of all studies included consequences questions suggests that post-passage effects are still not often evaluated in fishway studies. Furthermore, a large percentage of studies examining consequences of passage were from North America (85%) and concerned salmonid fishes (77%). If the ideal objective of passage facilities is to make them transparent to fish movements and have zero fitness effects, then post-passage consequences that are most of concern are those that may affect survival or reproduction. Clearly, an important requirement for fishways is that passage does not affect the ability to reach spawning grounds. This is particularly important for semelparous anadromous salmon since failure to complete spawning migrations results in zero lifetime reproductive success. Studies from the Columbia River system in the United States have monitored migration of Pacific salmon following passage through fishways and suggest that slow passage times (Naughton et al., 2005; Caudill et al., 2007) or falling back downstream of a dam after initial passage (Boggs et al., 2004) may be associated with greater mortality en-route to natal spawning tributaries. Effects of delay or slow passage time on subsequent survival may only be detectable over several dams (Naughton et al., 2005) suggesting a need to study cumulative effects of passage in watersheds with more than one facility. Although post-passage monitoring is necessary to meet passage objectives and mitigate the effects of dams and fishways, some energetic  28  costs and delays may be acceptable and natural in some situations, such as fishways constructed in areas naturally associated with difficult passage. Post hydro-system passage effects have also been shown for downstream migrating juvenile Pacific salmon. Passage through turbines (Ferguson et al., 2006) or transportation around dams by barge (Muir et al., 2006; Schreck et al., 2006) both resulted in delayed mortality for some fish that survived initial passage. Hydro-system passage can cause physiological stress in juveniles and mortality may result from increased vulnerability to predation and reduced disease resistance (Budy et al., 2002). For juveniles that are transported around dams by truck or barge, premature estuary arrival may also contribute to high mortality due to reduced growth opportunity and sizeselective predation (Muir et al., 2006). Studies of post-passage mortality for both juvenile and adult salmon in the Columbia River basin indicate that even though salmon pass fishways in large numbers, passage can have negative effects on fish long after they leave the dam area, stressing the importance of monitoring post-passage consequences. A number of studies assessed delayed mortality and survival to spawning grounds but our literature search yielded no articles that directly measured reproductive consequences of a fishway or other passage facility. Even for relatively well-studied salmon smolts in North America, important information gaps exist. For example, even though smolts may survive downstream passage to the ocean, it is imperative to examine whether there are consequences of passage facilities in the river on subsequent ocean behaviour and survival. Such studies may now be possible using a large-scale acoustic telemetry system, such as the Pacific Ocean Shelf Tracking (POST) array (Welch et al., 2008). Studies of post-passage consequences were rare in all parts of the world but especially in Europe, South America and Australia. Our search found only one article examining post-passage effects in a non-salmonid fish. A number of factors may contribute to this research gap. First, many evaluations are funded and carried out by operators who are mostly interested in acute local effects and have no incentive to document post-passage effects. Another factor could be that fishways in some areas, particularly in the tropics, are relatively recent and research is still in its early stages.  29  When evaluating passage facilities, documenting passage and quantifying efficiencies are certainly crucial first stages, whereas post-passage effects are typically only of interest once investigators know that large numbers of fish can pass the fishway. A third contributor to this knowledge gap could be that much less is known about the basic biology of tropical and sub-tropical fishes compared to salmonid species from temperate regions (Oldani et al., 2007). For under-studied fishes it is much more difficult to identify atypical behaviours, compare results to physiological baselines or determine the effects a fishway has on migration. In addition, methodologies, such as tagging and telemetry, and their effects on survival and behaviour are not well established for many tropical and other non-salmonid species, making studies of post-passage effects more difficult. Only seven studies (7% of total) examined the relationships between physiology and passage. Young et al. (2006) argued that the interface between physiology and life history is an important but understudied research area for fisheries management and conservation. This may be particularly so for the study of fish passage facilities since life-history, migrations, and physiology are closely linked in many fishes. However, based on the present analysis these topics have rarely been integrated in the context of barriers and fish passage facilities. One study ~ 25 years ago measured stress levels and reproductive maturity of Northern pike (Esox lucius, Esocidae) in order to link physiology, reproduction and migrations to upstream passage through a fishway. The authors concluded that fishways were necessary for reproductive migrations and that passage resulted in a moderate stress response (Schwalme et al., 1985). Two other studies examined how blood metabolites change in response to passage through a fishway (Connor et al., 1964; Dominy, 1971). Physiological techniques have also been used to examine consequences of passage for downstream migrating juvenile salmon. Ferguson et al. (2007) measured blood cortisol and lactate in salmon juveniles before and after dam passage, identifying physiological responses to passage via different bypass routes. Schreck et al. (2006) suggested that levels of osmotic preparedness for saltwater entry and parasitic infection  30  influence juvenile susceptibility to predation after dam passage. These studies highlight the importance of assessing physiological consequences of passage that may affect survival or reproduction and not just efficiency at the barrier. However, the vast majority of evaluations do not consider physiological effects of passage and therefore are not sufficient to assess whether passage has negative effects on fitness. Furthermore, physiological and behavioural responses to well-defined flow characteristics or structures may be applicable to other facilities and contribute to our fundamental understanding of fish responses to complex flows. Lastly, studies of physiology may also be important to determine how passage by fish in poor condition, when they have low energy reserves or high stress levels, may differ from passage by healthy fish. This quantitative review includes only peer-reviewed articles. During our literature search, we initially considered including graduate theses and dissertations and searched three databases containing these documents using the same keywords used for journal articles. In total this search yielded 7 unique articles that met our criteria, were available online, and were not also published as journal articles that were already included in our review. All of these articles were from North America. Although including theses and dissertations in the review would add 7 additional articles, it would not broaden the scope or change our conclusions. While we acknowledge that theses and dissertations are generally available online, databases containing theses and dissertations are rarely used by researchers and managers and these documents are therefore not widely read. Thus, we contend that while theses and dissertations may contain valuable results concerning fishway evaluations, they are not studies that are widely read by researchers, and therefore do not meet our criteria and should not be included in our literature search. A comprehensive search of fish passage facility evaluations in the grey literature, such as government or technical reports, was not possible. However, our assumption that the papers we reviewed from peer-reviewed publications are representative of the ‘monitoring’ type studies often reported in the grey literature is likely sound, as we would expect that routine monitoring studies would follow the approaches laid out by the more  31  exploratory scientific studies being conducted in the same region or on a particular species. One potential bias in our methods was that research from different regions that studied the same questions might not all have been published in peer-review journals. For instance, similar studies concerning fishway passage may have been conducted in different regions, but after one study was published in a peer-reviewed journal, investigators may have been less inclined to attempt to publish subsequent work feeling the questions are ‘already answered’. We are aware of several such ‘non peer-reviewed’ passage studies in Canada. Though we cannot assess how such a bias might affect the interpretation of our results, we would urge investigators to publish in peer-reviewed journals because of the unique nature of most fish passage facilities. Each fishway provides an ‘experiment’ and evaluations should consistently report standard measures of fishway performance (Castro-Santos et al., 2009) and be made available to the scientific community. Consistency of reporting would greatly facilitate future meta-analyses that would guide design or construction of new fishways, or help understand how management controls over flow or temperature downstream of a dam facility will likely influence a species or community of concern. Another potential bias is that only papers published in English, or those published in other languages but summarized and abstracted in English by the databases used, are included in this review. The English language bias in literature reviews and metaanalyses has been discussed in other fields of research, especially the medical sciences (Gregoire et al., 1995; Moher et al., 1996). In the present review, it is possible that this bias partly explains why there were fewer papers from South America and Europe than North America, and none from Asia or Africa. However, we have no reason to believe that fishway evaluations published in languages other than English are conceptually different, so this bias probably did not affect the conclusions drawn here.  Conclusions Fish passage facilities are inherently unique and each pose a different set of challenges and site-specific issues. This review highlights the diversity of approaches used in evaluating these facilities. One of the main differences among regions was that  32  mechanistic questions were studied much more often in North America than in Europe, South America or Australia. Mechanistic studies evaluating specific structures, hydraulic parameters or behaviours that affect passage are necessary to understand why fish may fail to pass. This type of information is necessary to modify facilities and improve fish passage. In addition, studies that focus on biological aspects of passage, such as fish behaviours in different hydraulic environments, are applicable to other passage facilities and expand the knowledge base of fishway science. Castro-Santos et al. (2009) recently suggested a framework for evaluating fishways in this manner, highlighting a suite of biologically relevant performance parameters and hydraulic covariates. More studies including mechanistic questions are necessary to improve passage facilities in Europe, South America and Australia. Insufficient monitoring and evaluation of passage facilities may partly explain why many fishways have failed to mitigate the effects of barriers on fishes and why population declines have continued in many places (Williams, 1998; Pelicice and Agostinho, 2008). In this analysis, consequences of passage were evaluated in only 22% of studies in North America, and rarely in other parts of the world. Of the studies that did assess consequences of passage, many point to serious negative impacts on fishes, including delayed mortality or failure to reach spawning sites. Facilities that cause long delays may exacerbate problems of energy depletion, disease and predation when fish accumulate in high densities above, below, or within fishways (Schreck et al., 2006; Agostinho et al., 2007b). To mitigate fitness effects of fishway passage, evaluations of passage facilities should examine sub-lethal consequences, delayed mortality, and fish physiology, in addition to traditional measures of efficiency and passage rates. Despite the large body of literature concerning passage at fishways and other facilities, several important information gaps exist, such as mechanisms of passage failure and post-passage consequences. Fortunately, several recent technological advances show great promise for studying these issues (Katopodis, 2005). Recent acoustic telemetry technology and analysis techniques allow tracking of fish in three dimensions at passage facilities (Steig and Timko, 2005). Electromyogram telemetry can  33  provide detailed information regarding swimming behaviour and energetics of fish (Cooke et al., 2004b) and has been applied successfully to fishway studies (Gowans et al., 2003; Brown et al., 2006; Pon et al., 2006). Other types of physiological telemetry and archival loggers that measure opercular rate, heart rate or tail-beat frequency are also available (Lucas et al., 1993; Cooke et al., 2004b) and have the potential to document physiological costs of fishway passage. Although three-dimensional and physiological telemetry have great potential for improving fishway science, issues such as high cost, invasive surgery and insufficient analytical methods currently limit the widespread use of these technologies in fishway evaluations. To understand the mechanisms of migrations and mitigate human impacts on fishes, interdisciplinary studies combining telemetry with disciplines like behaviour, physiology, functional genomics, and experimental biology are needed (Cooke et al., 2008). An interdisciplinary approach would allow fish passage scientists to address new questions regarding the consequences and mechanisms of passage as well as better resolve old issues, such as attraction to fishway entrances. Indeed, a recent study found that attraction efficiency by sockeye salmon (Oncorhynchus nerka, Salmonidae) at a British Columbia fishway was not related to physiological condition but was related to water discharge levels yet passage efficiency was correlated with an index of physiological stress (Pon et al., 2006). Plasma ion concentrations (in particular Na+) differed in sockeye which entered but failed to pass the fishway indicating the importance of understanding how downstream environments may affect the physiological state of migrants. Lastly, basic research concerning migration cues, fish behaviour and swimming mechanics in complex flows (e.g. Liao, 2007) will greatly benefit fishway science. Studies of fundamental biology are particularly needed for fish in the tropics, where little is known regarding migration cues and swimming abilities.  34  Table 2.1. Terms describing general research question types from summary of fish passage facility evaluations. The categories were not mutually exclusive and there was overlap between the ‘physiology’ category and both ‘mechanism’ and ‘consequences’ categories. Thus, a ‘physiology’ question could also be either a ‘mechanism’ or a ‘consequences’ question. Term  Definition  Examples of measures  Efficiency  Examines overall passage efficiency of individuals or species at passage facility  • Proportion of individuals successfully passing fishway • Number of species within a community observed passing fishway  Mechanism  Relates specific exogenous (environmental, structural or behavioural) factors to passage success/failure  • Discharge, temperature and structures associated with passage success/failure • Behaviours such as fallback, entrance attraction and delay • Efficiency for components of passage (guidance, attraction, passage)  Consequences  Quantifies individual level consequences of facility passage (i.e. post-passage effects)  • Delayed mortality • Injuries • Effects on reproductive success • Increased predation susceptibility  Physiology  Considers effect of initial physiology on passage or physiological consequences of passage  35  • Energetic costs • Metabolites, hormones, enzymes  Table 2.2. Classification of 96 journal articles concerning fish passage facility evaluations in terms of taxa and life-stage studied and types of general research questions included. The four types of research questions were as follows: (1) ‘Efficiency’ questions quantified the proportion of individuals able to pass a fishway, or qualitatively assessed which species in a community were able to pass; (2) ‘mechanism’ questions examined environmental, biological or structural factors that affected passage; (3) ‘consequences’ questions quantified post-passage effects on individual fish; (4) ‘physiology’ questions examined the relationship between passage and fish physiology. Articles are grouped by geographic location.  Physiology  Consequences  Mechanism  Efficiency  Research questions studied >1 stage  Juvenile only  Life-stage studied Adult only  Entire community  Non-salmonid  Reference  Salmonid  Taxa included  North America Beeman and Maule (2001) Boggs et al. (2004) Brown et al. (2006) Bunt et al. (1999) Bunt et al. (2000) Bunt (2001) Bunt et al. (2001) Burke and Jepson (2006) Castro-Santos and Haro (2003) Caudill et al. (2007) Connor et al. (1964) Damkaer and Dey (1989) Dominy (1971) Dominy (1973) Evans et al. (2008) Ferguson et al. (2006) Ferguson et al. (2007) Haro and Kynard (1997) Haro et al. (1998) Hiebert et al. (2000) Johnson and Moursund (2000) Johnson et al. (2005) Keefer et al. (2004) Kemp et al. (2006) Khan (2006) Kynard and Buerkett (1997) Kynard and O'Leary (1993) Libby (1981) Monk et al. (1989) Moser et al. (2000) Moser et al. (2002a)  * * *  *  * * * * * * * * *  *  * * * * * * * *  * *  * * * * *  * * * * * * * * * *  *  * * * * *  * * * * * * *  * * * * * *  36  * * * * * * *  * * * * * * * * * * * *  * * * * * * *  * * * * * * * * * * * * * * * * * *  * * * * * * * * *  * * * *  * * * * * * *  *  * *  *  *  *  * *  *  *  Moser et al. (2002b) Muir et al. (2001) Muir et al. (2006) Naughton et al. (2005) Naughton et al. (2006) Naughton et al. (2007) Nettles and Gloss (1987) Parsley et al. (2007) Reischel and Bjornn (2003) Saila et al. (1972) Schmetterling et al. (2002) Schreck et al. (2006) Schwalme et al. (1985) Scruton et al. (2002) Scruton et al. (2007) Skalski et al. (2002) Slatick and Basham (1985) Wertheimer (2007) Wertheimer and Evans (2005)  *  *  * * * * * *  * * * * * * *  * * * *  * * * * * * *  * * * * * * * * *  * *  * *  *  * * * *  *  * * *  * *  * * * * * * * * *  * * * * * * * * * * * * * * * * * *  * * *  * *  * *  *  *  Europe Aarestrup et al. (2003) Arnekleiv et al. (2007) Baras et al. (1994) Calles and Greenberg (2005) Calles and Greenberg (2007) Epler et al. (2004) Gosset et al. (2005) Gowans et al. (1999) Gowans et al. (2003) Jansen et al. (1999) Jensen and Aass (1995) Jungwirth (1996) Karppinen et al. (2002) Knaepkens et al. (2007) Knaepkens et al. (2006) Kotusz et al. (2006) Laine et al. (1998) Laine et al. (2002) Larinier and Boyer-Bernard (1991a) Larinier and Boyer-Bernard (1991b) Linlokken (1993) Lucas et al. (1999) Lundqvist et al. (2008) Luszczek-Trojnar et al. (2005) Prchalova et al. (2006) Santos et al. (2005)  * *  * * *  * * * * * * * * *  * * * * * * * * * *  * *  * * *  *  * *  * * * * * *  *  * * * * * * * * * *  *  *  * * * * * * * *  *  *  * * *  * * *  37  * * * * * *  * * * *  *  * * * * *  * *  * * * * * * * * * * * * * * *  *  * * * * * * *  *  Santos et al. (2002) Schmutz et al. (1998) Ziliukas and Ziliukiene (2002)  * *  * * *  * *  * * *  * * *  *  South America and Australia Agostinho et al. (2007a) Agostinho et al. (2007b) Alves (2007) Baumgartner and Harris (2007) Kowarsky and Ross (1981) Makrakis et al. (2007) Mallen-Cooper and Brand (2007) Mallen-Cooper and Stuart (2007) Morgan and Beatty (2006) Oldani and Baigun (2002) Oldani et al. (2007) Pelicice and Agostinho (2008) Pompeu and Martinez (2007) Stuart and Berghuis (2002) Stuart and Mallen-Cooper (1999) Stuart et al. (2007) Stuart et al. (2008)  * * * * * * * *  * * * * * * * *  *  * * * * * * * * *  38  * * * * * * * *  * * * * * * * * * * * * * * * * *  * * *  *  * * * * *  Table 2.3. Summary of categorization of 96 peer-reviewed articles about fish passage facility evaluations carried out in three geographic areas. Articles were categorized in terms of taxa, life stage and general research questions studied. Values are number of articles in each category and percent of the total number of articles from that geographic location. The four non mutually exclusive of research question type were as follows: (1) ‘Efficiency’ questions quantified the proportion of individuals able to pass a fishway, or qualitatively assessed which species in a community were able to pass; (2) ‘mechanism’ questions examined environmental, biological or structural factors that affected passage; (3) ‘consequences’ questions quantified post-passage effects on individual fish; (4) ‘physiology’ questions examined the relationship between passage and fish physiology.  Adult only  Juvenile only  >1 stage  Efficiency  Mechanism  Consequences  Physiology  %  Entire community  North America  Research questions studied  Non-salmonid  Location  Life-stage studied  Salmonid  Taxa included  66  40  4  66  28  6  96  90  22  12 50  n  33  20  2  33  14  3  48  45  11  6  %  79  55  38  76  7  17  97  55  3  3  n  23  16  11  22  2  5  28  16  1  1  %  0  100  94  59  0  41  100  47  6  0  n  0  17  16  10  0  7  17  8  1  0  %  58  55  30  68  17  15  97  72  14  7  n  56  53  29  65  16  15  93  69  13  7  Europe  South America & Australia  Number of articles  29  17  Total  96  39  Figure 2.1. Number of peer-reviewed journal articles concerning fish passage facility evaluations by year. All studies were conducted in one of three geographic areas shown.  40  Figure 2.2. Percentage of fishway evaluation articles published in different time periods that included four types of research questions. ‘Efficiency’ questions quantified the proportion of individuals able to pass a fishway, or qualitatively assessed which species in a community were able to pass. ‘Mechanism’ questions examined environmental, biological or structural factors that affected passage. ‘Consequences’ questions quantified post-passage effects on individual fish. ‘Physiology’ questions examined the relationship between passage and fish physiology. Numerals above bars are the number of studies represented by percentages.  41  References Aarestrup, K., M. C. Lucas, and J. A. Hansen. 2003. Efficiency of a nature-like bypass channel for sea trout (Salmo trutta) ascending a small Danish stream studied by PIT telemetry. Ecology of Freshwater Fish 12:160-168. Agostinho, A. A., L. C. Gomes, D. R. Fernandez, and H. I. Suzuki. 2002. Efficiency of fish ladders for neotropical ichthyofauna. River Research and Applications 18:299306. Agostinho, A. A., E. E. Marques, C. S. Agostinho, D. A. de Almeida, R. J. de Oliveira, and J. R. B. de Melo. 2007a. Fish ladder of Lajeado Dam: Migrations on one-way routes? Neotropical Ichthyology 5:121-130. Agostinho, C. S., A. A. Agostinho, F. Pelicice, D. de Almeida, and E. E. Marques. 2007b. Selectivity of fish ladders: A bottleneck in neotropical fish movement. Neotropical Ichthyology 5:205-213. Alves, C. B. M. 2007. Evaluation of fish passage through the Igarape' Dam fish ladder (Rio Paraopeba, Brazil), using marking and recapture. Neotropical Ichthyology 5:233-236. Arnekleiv, J. V., M. Kraabol, and J. Museth. 2007. Efforts to aid downstream migrating brown trout (Salmo trutta L.) kelts and smolts passing a hydroelectric dam and a spillway. Hydrobiologia 582:5-15. Baras, E., H. Lambert, and J. C. Philippart. 1994. A comprehensive assessment of the failure of barbus barbus spawning migrations through a fish pass in the canalized river Meuse (belgium). Aquatic Living Resources 7:181-189. Barrett, J. M., and M. Mallen-Cooper. 2006. The Murray River's 'sea to hume dam' fish passage program: Progress to date and lessons learned. Ecological Management and Restoration 7:173-183. Baumgartner, L. J., and J. H. Harris. 2007. Passage of non-salmonid fish through a Deelder lock on a lowland river. River Research and Applications 23:1058-1069. Beeman, J. W., and A. G. Maule. 2001. Residence times and diel passage distributions of radio-tagged juvenile spring Chinook salmon and steelhead in a gatewell and fish collection channel of a Columbia River dam. North American Journal of Fisheries Management 21:455-463. Behrens, M. D and Lafferty, K. D. 2007. Temperature and diet effects on omnivorous fish performance: implications for the latitudinal diversity gradient in herbivorous fishes. Canadian Journal of Fisheries and Aquatic Sciences 64:867-873.  42  Boggs, C. T., M. L. Keefer, C. A. Peery, T. C. Bjornn, and L. C. Stuehrenberg. 2004. Fallback, reascension, and adjusted fishway escapement estimates for adult Chinook salmon and steelhead at Columbia and Snake River dams. Transactions of the American Fisheries Society 133:932-949. Brander, K. M. 2007. Global fish production and climate change. Proceedings of the National Academy of Sciences of the United States of America 104:19709-19714. Brown, R. S., D. R. Geist, and M. G. Mesa. 2006. Use of electromyogram telemetry to assess swimming activity of adult spring Chinook salmon migrating past a Columbia River dam. Transactions of the American Fisheries Society 135:281-287. Budy, P., G. P. Thiede, N. Bouwes, C. E. Petrosky, and H. Schaller. 2002. Evidence linking delayed mortality of Snake River salmon to their earlier hydrosystem experience. North American Journal of Fisheries Management 22:35-51. Bunt, C. M. 2001. Fishway entrance modifications enhance fish attraction. Fisheries Management and Ecology 8:95-105. Bunt, C. M., S. J. Cooke, and R. S. McKinley. 2000. Assessment of the Dunnville Fishway for passage of walleyes from Lake Erie to the Grand River, Ontario. Journal of Great Lakes Research 26:482-488. Bunt, C. M., C. Katopodis, and R. S. McKinley. 1999. Attraction and passage efficiency of white suckers and smallmouth bass by two Denil fishways. North American Journal of Fisheries Management 19:793-803. Bunt, C. M., B. T. van Poorten, and L. Wong. 2001. Denil fishway utilization patterns and passage of several warmwater species relative to seasonal, thermal and hydraulic dynamics. Ecology of Freshwater Fish 10:212-219. Burke, B. J., and M. A. Jepson. 2006. Performance of passive integrated transponder tags and radio tags in determining dam passage behavior of adult Chinook salmon and steelhead. North American Journal of Fisheries Management 26:742-752. Cada, G. F. 1998. Fish passage mitigation at hydroelectric power projects in the United States. Pages 208-219 in M. Jungwirth, S. Schmutz, and S. Weiss, editors. Fish migration and fish bypasses. Fishing News Books, Oxford. Calles, E. O., and L. A. Greenberg. 2007. The use of two nature-like fishways by some fish species in the Swedish river Eman. Ecology of Freshwater Fish 16:183-190. Calles, E. O., and L. A. Greenberg. 2005. Evaluation of nature-like fishways for reestablishing connectivity in fragmented salmonid populations in the river Eman. River Research and Applications 21:951-960.  43  Castro-Santos, T., and A. Haro. 2003. Quantifying migratory delay: A new application of survival analysis methods. Canadian Journal of Fisheries and Aquatic Sciences 60:986-996. Castro-Santos, T., A. Cotel, and P. W. Webb. 2009. Fishway evaluations for better bioengineering: An integrative approach. in A. Haro, K.L. Smith, R.A. Rulifson, C. M. Moffit, R.J. Klauda, M. J. Dadswell, R.A. Cunjak, J.E. Cooper, K.L. Beal, and T.S. Avery, editors. Challenges for diadromous fishes in a dynamic global environment. American Fisheries Society Symposium, Bethesda, MD (in press). Caudill, C. C., W. R. Daigle, M. L. Keefer, C. T. Boggs, M. A. Jepson, B. J. Burke, R. W. Zabel, T. C. Bjornn, and C. A. Peery. 2007. Slow dam passage in adult Columbia River salmonids associated with unsuccessful migration: Delayed negative effects of passage obstacles or condition-dependent mortality? Canadian Journal of Fisheries and Aquatic Sciences 64:979-995. Clay, C. H. 1995. Design of fishways and other fish facilities, 2nd edition. Lewis Publishers, Boca Raton. Connor, A. R., C. H. Elling, E. C. Black, G. B. Collins, J. R. Gauley, and E. TrevorSmith. 1964. Changes in glycogen and lactate levels in migrating salmonid fishes ascending experimental endless fishways. Journal of the Fisheries Research Board of Canada 21:255-290. Cooke, S. J., S. G. Hinch, A. P. Farrell, D. A. Patterson, K. Miller-Saunders, D. W. Welch, M. R. Donaldson, K. C. Hanson, G. T. Crossin, M. S. Olsson, M. S. Cooperman, M. T. Mathes, K. A. Hruska, G. N. Wagner, R. Thompson, R. Hourston, K. English, S. Larsson, J. M. Shrimpton, and G. Van der Kraak. 2008. Developping a mechanistic understanding of fish migrations by linking telemetry with physiology, behavior, genomics and experimental biology: An interdisciplinary case study on adult Fraser River sockeye salmon. Fisheries 33:321-338. Cooke, S. J., S. G. Hinch, M. Wikelski, R. D. Andrews, L. J. Kuchel, T. G. Wolcott, and P. J. Butler. 2004a. Biotelemetry: A mechanistic approach to ecology. Trends in Ecology & Evolution 19:334-343. Cooke, S. J., E. B. Thorstad, and S. G. Hinch. 2004b. Activity and energetics of freeswimming fish: Insights from electromyogram telemetry. Fish and Fisheries 5:21-52. Damkaer, D. M., and D. B. Dey. 1989. Evidence for fluoride effects on salmon passage at John Day Dam, Columbia River, 1982-1986. North American Journal of Fisheries Management 9:154-162. Demirbas, A. 2007. Focus on the world: Status and future of hydropower. Energy Sources Part B-Economics Planning and Policy 2:237-242.  44  Dominy, C. L. 1971. Changes in blood lactic acid concentrations in alewives (Alosa pseudoharengus) during passage through a pool and weir fishway. Journal of the Fisheries Research Board of Canada 28:1215-1217. Dominy, C. L. 1973. Effect of entrance-pool weir elevation and fish density on passage of alewives (Alosa pseudoharengus) in a pool and weir fishway. Transactions of the American Fisheries Society 102:398-404. Eberstaller, J., M. Hinterhofer, and P. Parasiewicz. 1998. The effectiveness of two naturelike bypass channels in an upland Austrian river. Pages 363-383 in M. Jungwirth, S. Schmutz, and S. Weiss, editors. Fish migration and fish bypasses. Fishing News Books, Oxford. Epler, P., R. Bartel, M. Wozniewski, M. Duc, and D. Olejarski. 2004. The passage of fish through the fishway at Roznow Dam in the 1997-2003 period. Archives of Polish Fisheries 12:177-186. European Commission, 2000. Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for the Community action in the field of water policy. Official Journal of the European Communities – Legislative 327:1-72. Evans, S. D., N. S. Adams, D. W. Rondorf, J. M. Plumb, and B. D. Ebberts. 2008. Performance of a prototype surface collector for juvenile salmonids at Bonneville Dam's first powerhouse on the Columbia River, Oregon. River Research and Applications 24:960-974. Fahrig, L. 2003. Effects of habitat fragmentation on biodiversity. Annual Review of Ecology Evolution and Systematics 34:487-515. Ferguson, J. W., R. F. Absolon, T. J. Carlson, and B. P. Sandford. 2006. Evidence of delayed mortality on juvenile Pacific salmon passing through turbines at Columbia River dams. Transactions of the American Fisheries Society 135:139-150. Ferguson, J. W., B. P. Sandford, R. E. Reagan, L. G. Gilbreath, E. B. Meyer, R. D. Ledgerwood, and N. S. Adams. 2007. Bypass system modification at Bonneville Dam on the Columbia River improved the survival of juvenile salmon. Transactions of the American Fisheries Society 136:1487-1510. Goniea, T. M., M. L. Keefer, T. C. Bjornn, C. A. Peery, D. H. Bennett, and L. C. Stuehrenberg. 2006. Behavioral thermoregulation and slowed migration by adult fall Chinook salmon in response to high Columbia River water temperatures. Transactions of the American Fisheries Society 135:408-419.  45  Gosset, C., F. Travade, C. Durif, J. Rives, and P. Elie. 2005. Tests of two types of bypass for downstream migration of eels at a small hydroelectric power plant. River Research and Applications 21:1095-1105. Gowans, A. R., J. D. Armstrong, and I. G. Priede. 1999. Movements of adult Atlantic salmon in relation to a hydroelectric dam and fish ladder. Journal of Fish Biology 54:713-726. Gowans, A. R., J. D. Armstrong, I. G. Priede, and S. Mckelvey. 2003. Movements of Atlantic salmon migrating upstream through a fish-pass complex in Scotland. Ecology of Freshwater Fish 12:177-189. Gregoire, G., F. Derderian, and J. Lelorier. 1995. Selecting the language of the publications included in a metaanalysis - is there a tower-of-babel bias? Journal of Clinical Epidemiology 48:159-163. Haro, A., and B. Kynard. 1997. Video evaluation of passage efficiency of American shad and sea lamprey in a modified ice harbor fishway. North American Journal of Fisheries Management 17:981-987. Haro, A., M. Odeh, J. Noreika, and T. Castro-Santos. 1998. Effect of water acceleration on downstream migratory behavior and passage of Atlantic salmon smolts and juvenile American shad at surface bypasses. Transactions of the American Fisheries Society 127:118-127. Hiebert, S., L. A. Helfrich, D. L. Weigmann, and C. Liston. 2000. Anadromous salmonid passage and video image quality under infrared and visible light at Prosser Dam, Yakima River, Washington. North American Journal of Fisheries Management 20:827-832. Jansen, W., B. Kappus, J. Böhmer, and T. Beiter. 1999. Fish communities and migrations in the vicinity of fishways in a regulated river (Enz, baden-Württemberg, Germany). Limnologica - Ecology and Management of Inland Waters 29:425-435. Jensen, A. J., and P. Aass. 1995. Migration of a fast-growing population of brown trout (Salmo trutta L.) through a fish ladder in relation to water flow and water temperature. Regulated Rivers: Research & Management 10:217-228. Johnson, G. E., S. M. Anglea, N. S. Adams, and T. O. Wik. 2005. Evaluation of a prototype surface flow bypass for juvenile salmon and steelhead at the powerhouse of lower Granite Dam, Snake River, Washington, 1996-2000. North American Journal of Fisheries Management 25:138-151. Johnson, G. E., and D. D. Dauble. 2006. Surface flow outlets to protect juvenile salmonids passing through hydropower dams. Reviews in Fisheries Science 14:213244.  46  Johnson, R. L., and R. A. Moursund. 2000. Evaluation of juvenile salmon behavior at Bonneville Dam, Columbia River, using a multibeam technique. Aquatic Living Resources 13:313-318. Jungwirth, M. 1996. Bypass channels at weirs as appropriate aids for fish migration in rhithral rivers. Regulated Rivers-Research & Management 12:483-492. Karppinen, P., T. Maekinen, J. Erkinaro, V. Kostin, R. Sadkovskij, A. Lupandin, and M. Kaukoranta. 2002. Migratory and route-seeking behaviour of ascending Atlantic salmon in the regulated river Tuloma. Hydrobiologia 483:23-30. Katopodis, C. 2005. Developing a toolkit for fish passage, ecological flow management and fish habitat works. Journal of Hydraulic Research 43:451-467. Keefer, M. L., C. A. Peery, T. C. Bjornn, M. A. Jepson, and L. C. Stuehrenberg. 2004. Hydrosystem, dam, and reservoir passage rates of adult Chinook salmon and steelhead in the Columbia and Snake rivers. Transactions of the American Fisheries Society 133:1413-1439. Kemp, P. S., M. H. Gessel, B. P. Sandford, and J. G. Williams. 2006. The behaviour of Pacific salmonid smolts during passage over two experimental weirs under light and dark conditions. River Research and Applications 22:429-440. Kendall, V. J. and R. L. Haedrich. 2006. Species richness in Atlantic deep-sea fishes assessed in terms of the mid-domain effect and Rapoport’s rule. Deep-Sea Research I 53:506-515. Khan, L. A. 2006. A three-dimensional computational fluid dynamics (CFD) model analysis of free surface hydrodynamics and fish passage energetics in a vertical-slot fishway. North American Journal of Fisheries Management 26:255-267. Knaepkens, G., K. Baekelandt, and M. Eens. 2006. Fish pass effectiveness for bullhead (Cottus gobio), perch (Perca fluviatilis) and roach (Rutilus rutilus) in a regulated lowland river. Ecology of Freshwater Fish 15:20-29. Knaepkens, G., E. Maerten, and M. Eens. 2007. Performance of a pool-and-weir fish pass for small bottom-dwelling freshwater fish species in a regulated lowland river. Animal Biology 57:423-432. Kotusz, J., A. Witkowski, M. Baran, and J. Blachuta. 2006. Fish migrations in a large lowland river (Odra R., Poland) - based on fish pass observations. Folia Zoologica 55:386-398. Kowarsky, J., and A. H. Ross. 1981. Fish movement upstream through a central Queensland (Fitzroy River) coastal fishway. Australian Journal of Marine and Freshwater Research 32:93-109.  47  Kynard, B., and C. Buerkett. 1997. Passage and behavior of adult American shad in an experimental louver bypass system. North American Journal of Fisheries Management 17:734-742. Kynard, B., and J. O'Leary. 1993. Evaluation of a bypass system for spent American shad at Holyoke Dam, Massachusetts. North American Journal of Fisheries Management 13:782-789. Laine, A., T. Jokivirta, and C. Katopodis. 2002. Atlantic salmon, Salmo salar L., and sea trout, Salmo trutta L., passage in a regulated northern river - fishway efficiency, fish entrance and environmental factors. Fisheries Management and Ecology 9:65-77. Laine, A., R. Kamula, and J. Hooli. 1998. Fish and lamprey passage in a combined Denil and vertical slot fishway. Fisheries Management and Ecology 5:31-44. Larinier, M. 2002. Pool fishways, pre-barrage and natural by-pass channels. Bulletin Francais De La Peche Et De La Pisciculture 364:54-82. Larinier, M. 2001. Dams, fish and fisheries: opportunities, challenges and conflict resolution. FAO Fisheries technical paper No. 419, FAO, Rome, p. 45-90. Larinier, M., and S. Boyer-Bernard. 1991a. Downstream migration of smolts and effectiveness of a fish bypass structure at Halsou hydroelectric powerhouse on the Nive River. Bulletin Francais De La Peche Et De La Pisciculture 321:72-92. Larinier, M., and S. Boyer-Bernard. 1991b. Smolts downstream migration at Poutes Dam on the Allier River: Use of mercury lights to increase the efficiency of a fish bypass structure. Bulletin Francais De La Peche Et De La Pisciculture 323:129-148. Layman, C. A., J. P. Quattrochi, C. M. Peyer, and J. E. Allgeier. 2007. Niche width collapse in a resilient top predator following ecosystem fragmentation. Ecology Letters 10:937-944. Liao, J. C. 2007. A review of fish swimming mechanics and behaviour in altered flows. Philosophical Transactions of the Royal Society B-Biological Sciences 362:19731993. Libby, D. A. 1981. Difference in sex ratios of the anadromous alewife, Alosa pseudoharengus , between the top and bottom of a fishway at Damariscotta Lake, Maine. Fishery Bulletin 79:207-211. Linlokken, A. 1993. Efficiency of fishways and impact of dams on the migration of grayling and brown trout in the Glomma River system, South-Eastern Norway. Regulated Rivers-Research & Management 8:145-153.  48  Lucas, M. C., A. D. F. Johnstone, and I. G. Priede. 1993. Use of physiological telemetry as a method of estimating metabolism of fish in the natural environment. Transactions of the American Fisheries Society 122:822-833. Lucas, M. C., T. Mercer, J. D. Armstrong, S. McGinty, and P. Rycroft. 1999. Use of a flat-bed passive integrated transponder antenna array to study the migration and behaviour of lowland river fishes at a fish pass. Fisheries Research 44:183-191. Lundqvist, H., P. Rivinoja, K. Leonardsson, and S. McKinnell. 2008. Upstream passage problems for wild Atlantic salmon (Salmo salar L.) in a regulated river and its effect on the population. Hydrobiologia 602:111-127. Luszczek-Trojnar, E., P. Epler, T. Kopek, P. Szczerbik, M. Socha, and E. Drag-Kozak. 2005. The passage of fish through the fish pass in the Czchow Reservoir Dam (Southern Poland) in autumn. Acta Scientiarum Polonorum, Piscaria 4:83-88. Makrakis, S., M. C. Makrakis, R. L. Wagner, J. H. P. Dias, and L. C. Gomes. 2007. Utilization of the fish ladder at the Engenheiro Sergio Motta Dam, Brazil, by long distance migrating potamodromous species. Neotropical Ichthyology 5:197-204. Mallen-Cooper, M., and D. A. Brand. 2007. Non-salmonids in a salmonid fishway: What do 50 years of data tell us about past and future fish passage? Fisheries Management and Ecology 14:319-332. Mallen-Cooper, M., and I. G. Stuart. 2007. Optimising Denil fishways for passage of small and large fishes. Fisheries Management and Ecology 14:61-71. Moher, D., P. Fortin, A. R. Jadad, P. Juni, T. Klassen, J. LeLorier, A. Liberati, K. Linde, and A. Penna. 1996. Completeness of reporting of trials published in languages other than English: Implications for conduct and reporting of systematic reviews. Lancet 347:363-366. Monk, B., D. Weaver, C. Thompson, and F. Ossiander. 1989. Effects of flow and weir design on the passage behavior of American shad and salmonids in an experimental fish ladder. North American Journal of Fisheries Management 9:60-67. Morgan, D. L., and S. J. Beatty. 2006. Use of a vertical-slot fishway by galaxiids in Western Australia. Ecology of Freshwater Fish 15:500-509. Moser, M. L., A. M. Darazsdi, and J. R. Hall. 2000. Improving passage efficiency of adult American shad at low-elevation dams with navigation locks. North American Journal of Fisheries Management 20:376-385. Moser, M. L., A. L. Matter, L. C. Stuehrenberg, and T. C. Bjornn. 2002a. Use of an extensive radio receiver network to document Pacific lamprey (Lampetra tridentata)  49  entrance efficiency at fishways in the lower Columbia River, USA. Hydrobiologia 483:45-53. Moser, M. L., P. A. Ocker, L. C. Stuehrenberg, and T. C. Bjornn. 2002b. Passage efficiency of adult Pacific lampreys at hydropower dams on the lower Columbia River, USA. Transactions of the American Fisheries Society 131:956-965. Muir, W. D., D. M. Marsh, B. P. Sandford, S. G. Smith, and J. G. Williams. 2006. Posthydropower system delayed mortality of transported Snake River stream-type Chinook salmon: Unraveling the mystery. Transactions of the American Fisheries Society 135:1523-1534. Muir, W. D., S. G. Smith, J. G. Williams, and B. P. Sandford. 2001. Survival of juvenile salmonids passing through bypass systems, turbines, and spillways with and without flow deflectors at Snake River dams. North American Journal of Fisheries Management 21:135-146. Naughton, G. P., C. C. Caudill, M. L. Keefer, T. C. Bjornn, C. A. Peery, and L. C. Stuehrenberg. 2006. Fallback by adult sockeye salmon at Columbia River dams. North American Journal of Fisheries Management 26:380-390. Naughton, G. P., C. C. Caudill, M. L. Keefer, T. C. Bjornn, L. C. Stuehrenberg, and C. A. Peery. 2005. Late-season mortality during migration of radio-tagged adult sockeye salmon (Oncorhynchus nerka) in the Columbia River. Canadian Journal of Fisheries and Aquatic Sciences 62:30-47. Naughton, G. P., C. C. Caudill, C. A. Peery, T. S. Clabough, M. A. Jepson, T. C. Bjornn, and L. C. Stuehrenberg. 2007. Experimental evaluation of fishway modifications on the passage behaviour of adult Chinook salmon and steelhead at lower granite dam, Snake River, USA. River Research and Applications 23:99-111. Nehlsen, W., J. E. Williams, and J. A. Lichatowich. 1991. Pacific salmon at the crossroads: Stocks at risk from California, Oregon, Idaho, and Washington. Fisheries 16:4-21. Nettles, D. C., and S. P. Gloss. 1987. Migration of landlocked Atlantic salmon smolts and effectiveness of a fish bypass structure at a small-scale hydroelectric facility. North American Journal of Fisheries Management 7:562-568. Nilsson, C., C. A. Reidy, M. Dynesius, and C. Revenga. 2005. Fragmentation and flow regulation of the world's large river systems. Science 308:405-408. Odeh, M., editor. 1999. Innovations in fish passage technology. American Fisheries Society, Bethesda, MA.  50  Oldani, N. O., and C. R. M. Baigun. 2002. Performance of a fishway system in a major South American dam on the Parana River (Argentina-Paraguay). River Research and Applications 18:171-183. Oldani, N. O., C. R. M. Baigun, J. M. Nestler, and R. A. Goodwin. 2007. Is fish passage technology saving fish resources in the lower La Plata River basin? Neotropical Ichthyology 5:89-102. Parasiewicz, P., J. Eberstaller, S. Weiss, and S. Schmutz. 1998. Conceptual guidelines for nature-like bypass channels. Pages 348-362 in M. Jungwirth, S. Schmutz, and S. Weiss, editors. Fish migration and fish bypasses. Fishing News Books, Oxford. Parsley, M. J., C. D. Wright, B. K. van der Leeuw, E. E. Kofoot, C. A. Peery, and M. L. Moser. 2007. White sturgeon (Acipenser transmontanus) passage at the Dalles Dam, Columbia River, USA. Journal of Applied Ichthyology 23:627-635. Pelicice, F. M., and A. A. Agostinho. 2008. Fish-passage facilities as ecological traps in large neotropical rivers. Conservation Biology 22:180-188. Pompeu, P. D., and C. B. Martinez. 2007. Efficiency and selectivity of a trap and truck fish passage system in Brazil. Neotropical Ichthyology 5:169-176. Pon, L. B., S. J Cooke, and S. G. Hinch. 2006. Passage Efficiency and Migration Behaviour of Salmonid Fishes at the Seton Dam Fishway. Final Report for the Bridge Coastal Restoration Program, Project 05.Se.01, 105p. Prchalova, M., L. Vetesnik, and O. Slavik. 2006. Migrations of juvenile and subadult fish through a fishpass during late summer and fall. Folia Zoologica 55:162-166. Quigley, J. T., and D. J. Harper. 2006. Effectiveness of fish habitat compensation in Canada in achieving no net loss. Environmental Management 37:351-366. Reischel, T. S., and T. C. Bjornn. 2003. Influence of fishway placement on fallback of adult salmon at the Bonneville Dam on the Columbia River. North American Journal of Fisheries Management 23:1215-1224. Saila, S. B., T. T. Polgar, D. J. Sheehy, and J. M. Flowers. 1972. Correlations between alewife activity and environmental variables at a fishway. Transactions of the American Fisheries Society 101:583-594. Santos, J. M., M. T. Ferreira, F. N. Godinho, and J. Bochechas. 2005. Efficacy of a nature-like bypass channel in a Portuguese lowland river. Journal of Applied Ichthyology 21:381-388.  51  Santos, J. M., M. T. Ferreira, F. N. Godinho, and J. Bochechas. 2002. Performance of fish lift recently built at the Touvedo Dam on the Lima River, Portugal. Journal of Applied Ichthyology 18:118-123. Santos, H. D. E, P. D. Pompeu, and C. B. Martinez. 2007. Swimming performance of the migratory neotropical fish Leporninus reinhardti (Characiformes: Anostomidae). Neotropical Ichthyology 5:139-146. Schilt, C. R. 2007. Developing fish passage and protection at hydropower dams. Applied Animal Behaviour Science 104:295-325. Schmetterling, D. A., R. W. Pierce, and B. W. Liermann. 2002. Efficacy of three Denil fish ladders for low-flow fish passage in two tributaries to the Blackfoot River, Montana. North American Journal of Fisheries Management 22:929-933. Schmutz, S., C. Giefing, and C. Wiesner. 1998. The efficiency of a nature-like bypass channel for pike-perch (Stizostedion lucioperca) in the Marchfeldkanalsystem. Hydrobiologia 371-372:355-360. Schreck, C. B., T. P. Stahl, L. E. Davis, D. D. Roby, and B. J. Clemens. 2006. Mortality estimates of juvenile spring-summer Chinook salmon in the lower Columbia River and estuary, 1992-1998: Evidence for delayed mortality? Transactions of the American Fisheries Society 135:457-475. Schwalme, K., W. C. Mackay, and D. Lindner. 1985. Suitability of vertical slot and Denil fishways for passing north-temperate, nonsalmonid fish. Canadian Journal of Fisheries and Aquatic Sciences 42:1815-1822. Scruton, D., R. McKinley, N. Kouwen, W. Eddy, and R. Booth. 2002. Use of telemetry and hydraulic modeling to evaluate and improve fish guidance efficiency at a louver and bypass system for downstream-migrating Atlantic salmon (Salmo salar) smolts and kelts. Hydrobiologia 483:83-94. Scruton, D. A., C. J. Pennell, C. E. Bourgeois, R. F. Goosney, T. R. Porter, and K. D. Clarke. 2007. Assessment of a retrofitted downstream fish bypass system for wild Atlantic salmon (Salmo salar) smolts and kelts at a hydroelectric facility on the Exploits River, Newfoundland, Canada. Hydrobiologia 582:155-169. Sheer, M. B., and E. A. Steel. 2006. Lost watersheds: Barriers, aquatic habitat connectivity, and salmon persistence in the Willamette and lower Columbia River basins. Transactions of the American Fisheries Society 135:1654-1669. Skalski, J. R., R. Townsend, J. Lady, A. E. Giorgi, J. R. Stevenson, and R. D. McDonald. 2002. Estimating route-specific passage and survival probabilities at a hydroelectric project from smolt radiotelemetry studies. Canadian Journal of Fisheries and Aquatic Sciences 59:1385-1393.  52  Slaney, T. L., K. D. Hyatt, T. G. Northcote, and R. J. Fielden. 1996. Status of anadromous salmon and trout in British Columbia and Yukon. Fisheries 21:20-32. Slatick, E., and L. R. Basham. 1985. The effect of Denil fishway length on passage of some nonsalmonid fishes. Marine Fisheries Review 47:83-85. Steig, T. W., and M. A. Timko. 2005. Innovative techniques for analyzing the threedimensional behavioral results from acoustically tagged fish. Journal of the Acoustical Society of America 117:2367. Stuart, I. G., L. J. Baumgartner, and B. P. Zampatti. 2008. Lock gates improve passage of small-bodied fish and crustaceans in a low gradient vertical-slot fishway. Fisheries Management and Ecology 15:241-248. Stuart, I. G., and A. P. Berghuis. 2002. Upstream passage of fish through a vertical-slot fishway in an Australian subtropical river. Fisheries Management and Ecology 9:111-122. Stuart, I. G., A. P. Berghuis, P. E. Long, and M. Mallen-Cooper. 2007. Do fish locks have potential in tropical rivers? River Research and Applications 23:269-286. Stuart, I. G., and M. Mallen-Cooper. 1999. An assessment of the effectiveness of a vertical-slot fishway for non-salmonid fish at a tidal barrier on a large tropical/subtropical river. Regulated Rivers-Research & Management 15:575-590. Travade, F. and M. Larinier. 2002. Fish locks and fish lifts. Bulletin Francais De La Peche Et De La Pisciculture 364:102-118. Welch, D. W., E. L. Rechisky, M. C. Melnychuk, A. D. Porter, C. J. Walters, S. Clements, B. J. Clemens, R. S. McKinley, and C. Schreck. 2008. Survival of migrating salmon smolts in large rivers with and without dams. Public Library of Science Biology 6:e265. Wertheimer, R. H. 2007. Evaluation of a surface flow bypass system for steelhead kelt passage at Bonneville Dam, Washington. North American Journal of Fisheries Management 27:21-29. Wertheimer, R. H., and A. F. Evans. 2005. Downstream passage of steelhead kelts through hydroelectric dams on the lower Snake and Columbia rivers. Transactions of the American Fisheries Society 134:853-865. Weyand, M., M. Redeker, and E. A. Nusch. 2005. Restoration of fish passage: Development and results of a master plan established for the Ruhr River Basin. Water Science and Technology 52:77-84.  53  Williams, J. G. 1998. Fish passage in the Columbia River, USA and its tributaries: Problems and solutions. Pages 180-192 in M. Jungwirth, S. Schmutz, and S. Weiss, editors. Fish migration and fish bypasses. Fishing News Books, Oxford. Xenopoulos, M. A., D. M. Lodge, J. Alcamo, M. Maerker, K. Schulze, and D. P. Van Vuuren. 2005. Scenarios of freshwater fish extinctions from climate change and water withdrawal. Global Change Biology 11:1557-1564. Young, J. L., Z. B. Bornik, M. L. Marcotte, K. N. Charlie, G. N. Wagner, S. G. Hinch, and S. J. Cooke. 2006. Integrating physiology and life history to improve fisheries management and conservation. Fish and Fisheries 7:262-283. Yuksel, I. 2007. Development of hydropower: A case study in developing countries. Energy Sources Part B-Economics Planning and Policy 2:113-121. Ziliukas, V., and V. Ziliukiene. 2002. Ichthyological evaluation of fish passes constructed in Lithuania. Acta Zoologica Lituanica 12:47-57.  54  CHAPTER 3: Fishway passage and post-passage mortality of up-river migrating sockeye salmon in the Seton River, British Columbia.2 Introduction Lifetime reproductive success of anadromous and semelparous Pacific salmon (Oncorhynchus spp.) depends on successful completion of a single spawning migration. Consequently, these species are particularly vulnerable to fragmentation of the river corridor by human-made barriers. Dams have contributed to large declines in anadromous salmon throughout North America (Nehlsen et al., 1991; Slaney et al., 1996). At many dams, fishways have been built to enable passage of fishes over the barrier (Clay, 1995). However, a wide body of literature indicates that fishway passage efficiency is often low and many fishways continue to restrict movements of fish through a barrier (reviewed in Roscoe and Hinch, 2009). Even successful passage through a fishway can have deleterious effects on fish that could lead to delayed mortality or negatively affect fitness. For example, fishway passage can require high levels of energy-expenditure (Gowans et al., 2003; Brown et al., 2006), promote increased predation (Pelicice and Agostinho, 2008), or result in long delays (Bunt et al., 2000; Keefer et al., 2004), all of which could negatively affect fitness. Fishways can also cause injuries or scale loss through fish interactions with infrastructure (Castro-Santos et al., 2009). However, research evaluating fishway performance typically only documents usage by certain species or quantifies passage efficiency, and rarely considers post-passage effects or monitors behaviour and survival after passage (Roscoe and Hinch, 2009). In order to completely mitigate the impacts of barriers on fish populations, fishways need to enable passage without subsequent negative effects on fitness (Castro-Santos et al., 2009). Indeed, such an outcome is essential to ensuring that fishways do not compromise the welfare status of fish (Schilt, 2007).  2  A version of this chapter has been submitted for publication. Roscoe, D.W., S.G. Hinch, S.J. Cooke, and D.A. Patterson. Fishway passage and post-passage mortality of up-river migrating sockeye salmon in the Seton River, British Columbia. 55  Recent work in the Seton River in British Columbia, Canada (i.e. Pon et al., 2009a,b), has used electromyogram telemetry (EMG) and physiological biopsy to assess how swimming behaviour, stress physiology and dam-spill discharge affected fishway passage of sockeye salmon (Oncorhynchus nerka). The authors found that levels of stress and fishway attraction efficiency did not differ by level of dam-spill discharge but delays were greatest during intermediate flows (Pon et al., 2009a). Fish that failed to pass the fishway were not different from unsuccessful fish in terms of swimming speeds or energy use but unsuccessful fish had depressed plasma sodium levels, suggesting that they might be physiologically stressed (Pon et al., 2009b). However, like most fishway studies, fish were not monitored following passage, therefore the effects of delay and successful passage on migration success were not assessed. In a recent review of sexual variation in fisheries research (Hanson et al. 2008), the authors concluded that most management programs are lacking information on the importance of fish gender, and that this could have serious implications for evaluating or assessing management actions. Certainly, large sex differences exist in the migratory behaviour and fate of Pacific salmon. For example, female sockeye salmon swim using less energy per unit distance travelled (Hinch and Rand, 1998) but have higher passage failure rates in Hell’s Gate, a constricted and hydraulically challenging area of the Fraser River Canyon, BC (Gilhousen, 1990; Hinch and Bratty, 2000). Moreover, a recent study found that females had higher rates of en route mortality and were more susceptible to high temperature stress compared to males (Crossin et al., 2008). Similarly, a holding study manipulating water velocity during simulated spawning migration found that female sockeye salmon suffered higher mortality than males regardless of treatment (Nadeau et al., 2009). Therefore, in cases of passage through tailraces and fishways that are challenging for fish, one might predict poorer passage success and higher mortality in females compared to males. However, few studies evaluating fishway passage have considered the effects of sex on passage success. We evaluated the impact of a dam and fishway on sockeye salmon spawning migrations by assessing both success to ascend a fishway and success to reach spawning  56  grounds upstream of the fishway. One challenge in evaluating impacts of dams and fishways is the lack of a ‘control’ group since passage rates and levels of mortality prior to construction of these facilities are typically unknown (e.g. what would migration success be without the presence of the dam and fishway). To surmount this problem, we used an experimental approach, transporting and releasing fish at locations either immediately up- or down-stream of the dam and comparing mortality and behaviour between these groups. Based on previous work at this dam (Pon et al., 2009a,b), we predicted that some sockeye salmon would fail to pass the fishway. However, because fishway passage is physiologically and behaviourally challenging (Roscoe and Hinch, 2009), we hypothesized that successful fishway ascent would have post-passage consequences. We predicted that fish released downstream of the dam that re-ascended the fishway would have greater mortality en route to spawning grounds than fish released upstream of the dam. In light of previous research demonstrating sex differences in sockeye salmon in the Fraser River, we further predicted that fishway passage failure and en route mortality would be greater for female fish than male fish. Because transportation by truck can be stressful for salmonids, we evaluated the effects of our handling and transportation approach using non-lethal physiological biopsies. We measured a suite of indicators of stress from blood samples from fish immediately after fishway ascent, and from another group of fish after transportation and a 5-hour recovery period in net-pens. In sum, these measures of stress were used to assess physiological condition after fishway ascent, changes due to transportation and holding, and to interpret differences between en route mortalities and fish that reached spawning grounds. Physiological tools show great promise for understanding and mitigating the consequences of fishways and other hydropower infrastructure on fish (Hasler et al., 2009).  Methods Study site We studied the Gates Creek population of sockeye salmon during their migration through the Seton-Anderson watershed in South-Western British Columbia, Canada. Before reaching the study area adult sockeye had already migrated ~320 km from the  57  mouth of the Fraser River to the confluence of the Seton River. Our study area consisted of the final 55 km of their migration route, a migration corridor between the confluence and spawning areas at Gates Creek which included the Seton River, Seton Lake, Portage Creek, and Anderson Lake (Figure 3.1). A diversion dam spans the Seton River 760 m downstream of Seton Lake and the majority of the flow of the Seton River (up to 125 m3/s) is diverted into a 3.8 km long canal that delivers water to the hydroelectric power station on the Fraser River, 1.2 km downstream of the confluence with the Seton River. A vertical-slot fishway allows passage of fish over the Seton dam. The fishway consists of 32 pools, is 107 m long and has an overall grade of 6.9%. Discharge through the fishway is 1.3 m3/s throughout the year. Water is discharged at the dam through a sluice gate adjacent to the fishway entrance, intended to attract fish to the fishway, and through any of five siphons. During our study, there were two distinct levels of discharge at Seton dam, 35 m3/s (21-31 August) and 60 m3/s (15-20 August). Water temperature in the Seton River was measured using temperature loggers (iButton Thermochrons, DS1921Z, Maxim Integrated Products, Inc., Sunnyvale, CA) and ranged from 13˚C to 16˚C. Water temperature of the Fraser River at Lillooet, BC was obtained from Fisheries and Oceans Canada and ranged from 16˚C to 18˚C during August 2007 (D. Patterson, pers. comm., 2008), which is near or slightly cooler than historical averages (Patterson et al., 2007).  Fish capture, transport and holding All fish were captured by dip-net from the top pool of the Seton dam fishway, using a removable screen gate to temporarily block the upstream exit. Our general approach was to biopsy sample fish, implant them with acoustic telemetry transmitters and release them either up-stream of the dam at the capture site, or transport and release them down-stream of the dam. To assess passage efficiency and post fishway passage consequences, the ideal capture location would have been downstream of the dam in the Seton River, such that study fish would not have previously experienced the tailrace and fishway. However, it was not possible to catch sockeye salmon by dip- or drift-net anywhere in the lower Seton River because of low fish densities and lack of suitable capture locales. Thus, we caught all fish at the top of the fishway and acknowledge the  58  possibility that we were selecting for fish that already demonstrated the ability to locate and ascend the fishway. Because capture and transport of sockeye can cause certain blood metabolite and stress hormone levels to be elevated (Kubokawa et al., 1999) and some fish would be released at the capture site and others would be transported then released, we needed to evaluate and control for the effects of transportation. We held most of our fish for a 5hour in-river recovery period at the release site before biopsy sampling, tagging and release (hereafter ‘net-pen held’ fish). During this holding period the metabolite levels should have returned to near baseline (Milligan et al., 2000; Portz et al., 2006). An additional 20 sockeye were biopsy sampled, tagged and released immediately after capture from the top of the fishway (hereafter ‘control’ fish) to compare initial physiology of fish that were held to those not held. Transported fish were placed in an aluminium transport tank (1 m x 1 m x 1.5 m) filled with river water and continuously aerated with a 30 cm long air diffuser to maintain 100% oxygen saturation. Fish were then transported to one of the release sites where they were held in enclosures for 5hours, then biopsied, tagged and released. A 4 m x 8 m x 4 m enclosure consisting of an aluminium tubing frame, vinyl sides and bottom and nylon mesh ends was used to hold fish during the recovery period. The enclosure was placed in the river at the release site such that a steady current of water passed through it, requiring fish to swim slowly to maintain position but without becoming exhausted. A maximum of 12 fish were transported in the tank and then held in the enclosure at one time.  Tagging, physiological biopsy and tracking Tagging and biopsy procedures followed those of Cooke et al. (2005). Fish were restrained in a V-shaped foam-padded trough continuously supplied with fresh river water. A 1.5 mL blood sample was taken from the caudal vasculature (Houston, 1990) using a heparinized Vacutainer syringe (1.5 inches, 21 gauge; lithium heparin). Blood samples were centrifuged for 6 minutes to separate plasma from red blood cells, and plasma was temporarily stored in liquid nitrogen before transfer to a -80˚C freezer. Fork length was measured to the nearest 5 mm. A small tissue sample was removed from the  59  adipose fin using a hole punch and stored in ethanol for subsequent DNA analysis to confirm population of origin (Beacham et al., 2004). Somatic lipid concentration was measured using a hand-held microwave energy meter (Fatmeter model 692, Distell Inc., West Lothian, Scotland, UK) and converted to estimates of gross somatic energy (GSE) using relationships described by Crossin and Hinch (2005). Fish were marked with an external tag (FT-4 Cinch up, Floy Tag Inc., Seattle, WA) attached through the dorsal musculature immediately anterior to the dorsal fin using a hollow needle. The external tag permitted visual identification of study sockeye salmon on spawning grounds or if they were caught by fisheries. An acoustic telemetry transmitter (V16-1H-R64K coded tags, Vemco Inc., Shad Bay, NS) was inserted gastrically using a tag applicator consisting of a hollow plastic tube and plunger to expel the tag. The entire tagging and biopsy procedure lasted less than 3 minutes, after which fish were held for recovery in a net-pen. After the holding period, fish were released at one of three locations (Figure 3.2): 1) Powerhouse tailrace on the Fraser River, 2) lower Seton River at confluence of Cayoosh Creek, or 3) Seton Lake near outflow. The 20 control fish sampled immediately after capture and released without a recovery period were released directly upstream of the dam into the Seton River. A fixed array of acoustic telemetry receivers (VR2, Vemco Inc., Shad Bay, NS) was used to monitor fish movements. Seventeen receivers were deployed underwater in strategic locations along the migration route including one in the Fraser River at the powerhouse tailrace, two in the lower Seton River, two in the tailrace of Seton dam, one in the upper Seton River, and four in each of Seton and Anderson Lakes (Table 3.1). In addition, receivers were placed near the bottom, middle and top of the fishway to detect entrance into and ascent of the fishway.  Physiological analysis We measured a suite of variables from blood plasma samples that were used as indices of physiological stress or exhaustion. Plasma lactate and glucose concentrations were measured using YSI 2300 STAT Plus glucose and lactate analyzer (YSI Inc., Yellow Springs, OH, USA). Plasma chloride concentrations were measured in duplicate  60  using a model 4425000 digital chloridometer (Haake Buchler Instruments, Saddle Brook, NJ, USA). Concentrations of plasma sodium and potassium ions were measured in duplicate using a model 410 Cole-Palmer flame photometer (Vernon Hills, IL, USA) calibrated to a 4-point standard curve prior to use and after every 10 samples. Plasma osmolality was measured using a model 3320 freezing point osmometer (Advanced Instruments, Norwodd, MA, USA). Cortisol, 17ß-estradiol and testosterone concentrations were measured in duplicate using enzyme-linked immunosorbent assay (ELISA) kits (Neogen Co., Lexington, KY, USA). Plasma testosterone and 17ß-estradiol were ether-extracted according to kit directions prior to assaying. Measurements were repeated if the coefficient of variation between replicates was greater than 10%. To determine the sex of individual fish 17ß-estradiol was plotted versus testosterone resulting in two distinct clusters of points, which corresponded with males and females.  Data analysis To evaluate the ability of the telemetry receiver array to detect fish we calculated detection efficiency using the method of Jolly (1982) as described by Welch (2007). Fishway entrance efficiency was calculated by the number of fish detected in the fishway (either of receivers 6 or 7) divided by the number of fish detected in the tailrace of the dam (either of receivers 4 or 5). Fishway passage efficiency was calculated as the number of fish that reached the top pool of the fishway divided by the number of fish known to have initially entered the fishway (i.e. detected on receiver 6). Gates Creek sockeye salmon spawn in natural areas in Gates Creek, as well as in an artificial spawning channel ~1 km from the mouth of Gates Creek, and reception of acoustic telemetry receivers would be poor in both of these areas. Therefore, fish that were detected on the receiver in Anderson Lake at the mouth of Gates Creek (#17; Table 3.1) were considered to be successful migrants. Travel speed between the outflow of Seton Lake and the inlet of Anderson Lake was calculated by the distance divided by the difference in time of first detection at these two locations. The proportion of individuals surviving to spawning grounds was compared between males and females and fish released up- and down-stream of the dam using chi-  61  square contingency test, or in cases where expected cell sizes were less than five, Fisher’s exact test. Measures of blood biochemistry (lactate, glucose, ions, osmolality, hormones), GSE, fork length and travel speeds were compared between net-pen held and control fish and between sexes using two-way analysis of variance (ANOVA). Two-way ANOVA was also used to assess differences in blood biochemistry, GSE and fork length between fish that reached spawning grounds (‘successful migrants’) and those that did not (‘mortalities’) while accounting for sex differences. The variables lactate, glucose, Na+, K+, Cl-, osmolality, testosterone and travel speed needed to be log-10 transformed to meet assumptions of normality and homoscedasticity (Zar, 1999). In cases where there was a significant interaction between factors, a Tukey-Kramer multiple comparison test was used to compare recovery treatments (‘net-pen held’ or ‘control’) or fate groups (successful migrant or mortality) for both males and females. A significance level of 0.05 was used for statistical tests but Bonferroni corrections were made for ANOVA models, because there were multiple comparisons, resulting in a significance level of 0.005. Analyses were carried out in SAS v.9.1.3 (SAS Inc., Cary, N.C.).  Results High detection efficiencies at most receiver stations indicated a good ability to detect fish movements and determine individual fate of fish (Table 3.1). Detection efficiencies at receivers in Seton and Anderson lakes were all 100%. Efficiencies at the first two receivers in the lower Seton River (# 2 and 3) were lower (48% and 75%) and therefore we could not confidently detect fish movements between the mouth of the Seton River and the dam. However, the two redundant receivers in the dam tailrace had a detection efficiency of 95% suggesting a good ability to detect whether or not fish reached the tailrace of the dam. Receivers in the fishway had efficiencies of 100%, 74% and 91% for stations at the top, middle and bottom, respectively. Thus, the ability to detect fish that entered the fishway was high (91%) and if the bottom and middle fishway receivers were used together (redundantly) to detect fishway entrance, efficiency improved to 95%.  62  Eighty-eight sockeye were caught, biopsied and tagged between the 15th and 24th of August, 2007. DNA analyses indicated that 87 of the fish were from the Gates Creek population and one was a stray from the Chilko population, which was eliminated from all analyses. In total, there were 33 fish released into the powerhouse tailrace on the Fraser River, 27 fish released into the lower Seton River at Cayoosh Creek, 8 fish released into Seton Lake near the mouth, and 20 fish released upstream of the dam without a recovery period. When analyzing the telemetry data, we observed that three fish ascended the fishway and arrived at the top pool at times when we had blocked the upstream exit in order to capture and tag fish. These fish descended and moved downstream and were not subsequently detected the fishway. These three fish were included in estimates of fishway passage (i.e. they were successful in passing fishway) but excluded from analyses of fate. Comparisons of blood physiology, body length and energy between net-pen held and control fish and between sexes revealed a significant interaction between sex and recovery holding treatment for the variables glucose and K+ (P<0.05, two-way ANOVA; Table 3.2). Tukey-Kramer tests indicated that glucose was significantly higher in net-pen held versus control fish for both males (P=0.0009) and females (P<0.0001), and that K+ was higher in net-pen held versus control females (P<0.0001) but not different between net-pen held and control males (P=0.7). Net-pen held fish had significantly lower testosterone and Cl-, and shorter fork length compared to control fish although Cl- was not significant after Bonferroni correction (Table 3.2). Females had significantly higher cortisol, testosterone, and GSE, and lower Na+ compared to males (Table 3.2). The sexspecific hormone 17ß-estradiol was not different between net-pen held and control females (P=0.42). To assess differences in physiology, size and energy between successful migrants and mortalities we conducted a series of two-way ANOVAs with fate and sex as factors. In these models, only fish released downstream of the dam were included because so few fish released upstream were mortalities (see below). Glucose was higher in mortalities than successful migrants (P=0.027), though the difference was not significant after  63  Bonferroni correction. In all other models, fate was not a significant factor, suggesting that successful migrants were not different from mortalities in terms of GSE, length, and most measures of blood biochemistry. The female hormone 17ß-estradiol was not different between fate groups (P=0.9). Survival to spawning grounds was much lower for the fish released downstream of the dam (48%) than for fish released upstream of the dam (93%; P<0.0001).  Among  fish released downstream of the dam, females had significantly lower survival to spawning grounds (40% of 38 fish) than males (71% of 17 fish; P=0.03). These results are consistent among the two groups of fish released upstream of the dam, as survival to spawning grounds was not significantly different between fish released immediately after capture (95%) and those released after transportation and net-pen holding (88%; P=0.5). Similarly, survival was not different between fish released at the two sites downstream of the dam (50% and 47%; P=0.8). Mortality occurred in all sections of the migration route including the lower Seton prior to reaching the dam, at the dam and fishway, and in Seton and Anderson lakes (Table 3.3). Of 59 fish released downstream of the dam, 14% were not detected at, and likely did not reach the tailrace of the dam. Because detection efficiency was poor in the lower Seton River and at the powerhouse tailrace on the Fraser, the exact fate of these fish is unknown. Three of the eight fish were never detected anywhere on the receiver array, and, since all tags were known to be functioning properly, are presumed to have moved back into the Fraser River. Twenty percent of fish that reached the dam tailrace failed to pass the fishway. Attraction efficiency of the fishway was 85%, since 44 of 51 fish detected in the dam tailrace located and entered the fishway. Only three fish that entered the fishway failed to ascend the entire length, therefore, the passage efficiency was 93%. Of fish that reached the dam tailrace, 15 of 16 males (94%) and 26 of 35 females (74%) passed the fishway but this difference in passage efficiency was not statistically significant (P=0.14).  64  In Seton and Anderson lakes, there was greater mortality of fish released downstream of the dam compared to those released upstream (P=0.04). Of all the fish released downstream of the dam that successfully passed the fishway and entered Seton Lake (n=37), 27% died before reaching spawning grounds. This represents 18% of the total number of fish released downstream of the dam. In-lake mortality was 7% for fish released upstream of the dam. Only one fish (released in lower Seton River) was known to be caught by the small subsistence fishery in Portage Creek, the stream connecting the two lakes, and the rest of in-lake mortalities died of unknown causes. Travel speed through the lakes was not different between fish that were released downstream of the dam and fish released upstream of the dam (P=0.11).  Discussion In order to assess whether our methodology of transporting fish below the fishway as a means to ultimately study post-passage consequences had any effects on our fish, we first assessed indices of physiological stress of control fish sampled immediately after fishway ascent, and compared them to literature values for ‘healthy’ up-river migrating sockeye salmon. We found that sockeye sampled at the top of the fishway did not show signs of severe stress or anaerobic exhaustion, corroborating previous work that suggested that fishway ascent did not cause severe metabolic or ionic disturbances for sockeye salmon (Pon et al., 2009b). Plasma lactate (1.7-2.2 mmol) and glucose levels (4.4-4.9 mmol) were similar to or lower than levels previously reported for adult sockeye in the late stages of migration (e.g. Young et al., 2006). Plasma ion concentrations and total osmolality were also very similar to values reported in previous work on adult sockeye in freshwater (Young et al., 2006; Crossin et al., 2008; Pon et al., 2009b). Cortisol levels were within the range reported by other studies of sockeye (Cooke et al., 2006; Pon et al., 2009b) although cortisol titres can vary considerably during migration (Hinch et al., 2006) and among populations (Cooke et al., 2006). There were relatively few differences in stress physiology between fish sampled immediately after fishway ascent compared to fish sampled after transportation and a 5hour net-pen holding period. This suggests that either transportation did not severely  65  stress fish, or that most indices of stress (i.e. cortisol, lactate, and ions) returned to normal levels during the holding period. We did, however, find that the concentration of glucose was higher and testosterone was lower in net-pen held fish compared to control fish, differences that were likely related to confinement stress during transportation and holding. The non-specific stress response in salmonids involves an initial increase in catecholamines and cortisol, often referred to as the primary stress response, followed by increases in glucose and other metabolites, known as the secondary stress response (Mazeaud et al., 1977; Barton, 2002; Portz et al., 2006). Other studies have reported primary and secondary stress responses to confinement in sockeye (Kubokawa et al., 1999) and other salmonids (Wedeymer and Wydoski, 2008). High levels of stress are also associated with depressed reproductive hormones (Kubokawa et al., 1999; Hinch et al., 2006). In our study, cortisol may not have been different at the time of sampling (5 hours after confinement) because it is a fast and transient response that can return to normal levels in salmonids after 60 minutes of confinement (Portz et al., 2006). Females had initially higher levels of stress than males, as indicated by concentrations of cortisol, glucose and lactate, and larger changes in glucose and testosterone after net-pen confinement. Both of these findings are consistent with previous research concerning sex-specific stress levels and responses in sockeye salmon (Kubokawa et al., 1999; Hinch et al., 2006). There were also modest differences in plasma ion concentrations, including higher K+ in net-pen held than control females. Muscle contraction during exercise can cause an efflux of potassium from muscle into the plasma in rainbow trout (Oncorhynchus mykiss; Nielsen et al., 1994; van Ginneken et al., 2004). Thus, K+ may have been elevated due to swimming up the fishway, and returned to normal concentration after net-pen holding. Net-pen held fish also had lower plasma Clconcentrations than control fish, although the difference was not significant after Bonferroni correction. Loss of plasma ions in response to stress results mostly from increased efflux across the gills (Macdonald and Milligan, 1997) and in this study could have been related to confinement stress previously mentioned. Although there were some differences in plasma ion concentrations between net-pen held and control fish  66  there were not changes in total osmolality, or in Na+, and values of K+ and Cl- were not critically high or low. Therefore, the changes in ion concentrations were not deemed to be physiological significant or such that changes in behaviour or survival would be expected. Overall, we found little evidence that fishway passage or previous experience in the tailrace of the dam resulted in physiological stress or exhaustion. Indices of stress in sockeye salmon sampled immediately after fishway ascent were low compared to several previous reports of blood biochemistry in the same species. After transportation and netpen holding fish were in good condition although higher glucose and lower testosterone compared to control fish suggests that there was a mild stress response to confinement. Regardless, we did not observe relatively large changes in metabolites or osmoregulatory function related to transportation or net-pen confinement such that we would expect subsequent behaviour or survival to be affected. As further evidence that our handling and transportation approaches were relatively benign, we found that net-pen held and control fish released upstream of the dam did not differ in their survival rates to spawning grounds. This finding corroborates other telemetry studies that involved transporting Fraser River sockeye salmon among sites or holding facilities (Hinch and Bratty, 2000; Crossin et al., 2008). Our results indicate that the hydroelectric facilities in the Seton River have a significant impact on spawning migration of sockeye salmon, as approximately half of migrating adults released downstream of the dam failed to reach spawning areas. Mortality occurred not only at the dam and fishway, but also in the lower Seton or Fraser River prior to reaching the dam, and in Seton and Anderson lakes. Similar patterns of passage failure at several different locales along the migration route resulting in high cumulative mortality have been observed by others studying Pacific salmon (Naughton et al., 2005; Keefer et al., 2008) and Atlantic salmon (Salmo salar; Gowans et al., 2003; Lundqvist et al., 2008). These studies suggest a need to assess cumulative impacts in systems with several passage facilities or locales of difficult passage. In some years in the Fraser River, high levels (e.g. 20-90%) of migrating adult sockeye salmon can perish  67  en route to spawning grounds (Macdonald, 2000; Macdonald et al., 2000; Cooke et al., 2004; Quinn, 2005), often as a result of high river temperatures or discharge. The high levels of mortality observed in our study (~50% of fish released downstream of dam) are alarming because river temperatures and discharge were not unusually high that year (Patterson et al., 2007) and because mortality occurred over a very short spatial scale. It was surprising that some fish failed in the lower Seton River before reaching Seton Dam as these individuals were initially able to reach and ascend the fishway where they were first captured. The distances from each of the release sites to the dam were relatively short (~5 km from the powerhouse tailrace and 1.3 km from lower Seton release site) and probably not hydraulically challenging for strong swimming fish like sockeye salmon. One factor that could have contributed to en route losses in this section is attraction of fish to water discharge at the powerhouse tailrace. Discharge from the powerhouse consists of pure “homestream” Seton Lake water whereas flows in the Seton River are an engineered mixture of Seton Lake water spilled at the dam and water from Cayoosh Creek, a tributary joining the Seton River 1.3 km downstream of the dam. Fretwell (1989) previously reported attraction of sockeye salmon to the powerhouse tailrace and found that delays before entering the Seton River depended on the ratio of Cayoosh Creek to Seton Lake water. If Seton River flows consisted of greater than 20% Cayoosh Creek water then sockeye were more attracted to discharges from the powerhouse, resulting in significant delay. Based on these studies Seton River flows are maintained at less than 20% Cayoosh Creek water during the spawning migration period. In our study, because detection efficiency of the receiver in the tailrace was poor, it is difficult to determine whether tailrace attraction may have caused migratory delay and contributed to mortality. A large portion of the total mortality (~ 20%) occurred at the dam and fishway, a finding consistent with a previous telemetry study at the Seton Fishway (Pon et al., 2006) confirming that this locale is a limiting factor for sockeye migrations in the watershed. In both the present and Pon et al. (2006) studies passage efficiency was much higher (93% in this study, 100% in Pon et al., 2006) than attraction efficiency (86% in this study, 77%  68  in Pon et al., 2006) suggesting that most of passage failure was associated with failure to locate the fishway entrance and not passage itself. In comparison, total efficiency at individual dams on the Columbia River ranged from 90% to 100% for radio-tagged Chinook salmon (Bjornn et al., 2000). Many studies of Atlantic salmon have reported low passage efficiencies at fishways (23%, Karppinen et al., 2002; 63%, Gowans et al., 2003; 0%, Thorstad et al., 2003; 21%, Lundqvist et al., 2008). Although passage efficiency of anadromous salmonids is lower at many fishways compared to at Seton dam, the fact that ~20% of all sockeye salmon migrants are unable to pass the Seton fishway suggests a need to improve passage at this location. Furthermore, all fish in our study were captured at the top of the fishway and had therefore already demonstrated the ability to locate and ascend the fishway, whereas some fish never initially located the fishway and were not represented in our estimates of passage efficiency. Therefore, passage efficiency at the Seton fishway may in fact be lower than our estimates of ~80% (Pon et al., 2006 and this study). Mortality in the lakes was higher for fish that were released downstream of the dam (27%) than for fish released upstream of the dam (7%), supporting the hypothesis that ascent of the fishway has post-passage consequences on survival. All fish were caught at the top of the fishway, and had therefore already ascended the fishway once. However, re-ascent of lower Seton River and fishway had some effect on fish that resulted in subsequent high mortality en route to spawning grounds. The mechanism of this high in-lake mortality is not clear. If mortality was related to exhaustion or physiological stress caused by fishway entrance or ascent, we would expect fish that died before reaching spawning grounds to exhibit higher levels of stress at release compared to successful migrants. We did find that fish that died before reaching spawning grounds had higher glucose than successful migrants. However, none of the other physiological measures differed by fate and glucose levels of mortalities were still lower than wild sockeye from other studies (e.g. Cooke et al., 2006; Crossin et al., 2007) and not critically high such that mortality would be expected. Therefore, mortality in the lakes following fishway ascent did not appear to be related to high levels of acute measures of physiological stress.  69  Other researchers have hypothesized that low initial energy levels and depletion of energetic reserves may contribute to migration failure in anadromous salmon (Cooke et al., 2004; Caudill et al., 2007). In our study, all individuals had GSE levels at the time of release that were at least 25% greater than proposed threshold energy level required to sustain life (4 MJ kg-1; Crossin et al., 2004). Furthermore, GSE was not initially lower in in-lake mortalities compared to successful migrants. Although fishway ascent was not energetically demanding at Seton dam, observations of burst swimming in the tailrace suggest that energy use could be high at this locale (Pon et al., 2009b). Others have also reported that swim speeds were highest in tailraces compared to in fishways or forebays (Brown et al., 2006; Scruton et al., 2007; Enders et al., 2008). We did not find direct evidence of energy limitation in our study. However, it is possible fish that were delayed below the fishway or at the powerhouse tailrace exhausted their energy reserves or ran out of time before reaching spawning grounds and we cannot rule out the role of energy depletion in en route mortality. As predicted, we found that female sockeye suffered greater en route mortality than males. Fishway passage failure was also higher in females although the difference was not significantly significant. Greater passage failure of female compared to male sockeye salmon has previously been reported in years of difficult migration conditions in the Fraser River Canyon (Gilhousen, 1990). Patterson et al. (2004) and Nadeau et al. (2009) both found that mortality was greater for females than males in holding studies of sockeye salmon near the end of freshwater migration. Similarly, Crossin et al. (2008) found that female sockeye were more physiologically stressed in response to temperature holding treatments and suffered higher mortality than males during subsequent migration to spawning grounds. A study of anadromous brown trout (Salmo trutta) in the river Eman, Sweden found that more males than females successfully passed upstream of a series of hydroelectric power plants, although the difference was not statistically significant (Calles and Greenberg, 2009). All these results contrast with studies of Pacific salmon migration through the hydroelectric system in the Columbia River, which found no differences in mortality (Keefer et al., 2008) or passage success (Naughton et  70  al., 2005; Caudill et al., 2007) between the sexes. The reasons for higher female mortality are not clear although Crossin et al. (2008) hypothesized that greater energetic investment in reproductive development make females less able to buffer against the effects of environmental stressors. Whatever the mechanisms involved, the finding that females suffer higher en route mortality has important implications for conservation and management. Estimates of en route mortality that pool sexes may underestimate female mortality. Population level effects of higher female en route mortality could be significant since total spawning success of a population is governed mostly by female success whereas loss of males has little effect on subsequent generations (Gilhousen, 1990). Because male and female sockeye salmon may differ in physiology, energetics and survival it is important to include sex as a factor in future research and management programs, as was recently suggested by Hanson et al. (2008). This study demonstrates the importance of monitoring fish after they pass fishways to incorporate potential post-passage consequences in evaluations of fishway performance. In addition, consequences of fishway passage such as physiological stress, energy use, or physical injury are likely to be associated with fitness costs (Castro-Santos et al., 2009) although no previous studies have studied effects of passage on reproductive success. Because we did not assess spawning success of fish in our study, the impact of the fishway on Gates Creek sockeye salmon may be even greater than shown. For instance, Gates Creek sockeye suffer high levels of pre-spawn mortality (i.e. dieing on spawning grounds without reproducing) relative to many other Fraser River populations (Gilhousen, 1990) but it is not known whether hydroelectric facilities may be a contributing factor. Finally, though we found that our transportation and holding approaches likely did not affect survival or behaviour, others have found that net-pen holding can cause significant physiological stress (Wedemeyer and Wydoski, 2008) or altered migration behaviour (Bromaghin et al., 2007). Few studies of fishway passage have evaluated the role that stress may have on behaviour and fate (reviewed in Roscoe and Hinch, 2009). We recommend that future studies of migrating fish which involve transport or net-pen confinement should assess their methodologies, and utilize as part of their interpretations, the physiological status of their fish.  71  Table 3.1. Location and detection efficiency of acoustic telemetry receivers used to track Gates Creek sockeye migrations in 2007. Receivers 4 and 5 were considered redundant, so that fish detected at either receiver were known to have reached the dam, and hence, the receivers worked as one station with a single detection efficiency. Figures 3.1 and 3.2 show the location of telemetry receivers. ID #  Approximate location  Detection efficiency  1  Powerhouse tailrace (Fraser River)  n/a  2  Seton River, ~1.3 km upstream from mouth  74%  3  Seton River at Cayoosh Creek  48%  4  Seton River, ~80 m downstream of dam  5  Below dam, end of radial gate channel  6  Fishway, bottom (Pool 3)  91%  7  Fishway, 1/2 way, (Pool 17)  75%  8  Fishway, top (Pool 32)  100%  9  Seton River, ~160 m upstream of dam  98%  10  Outflow of Seton Lake  100%  11  Seton Lake, middle  100%  12  Seton Lake, West end  100%  13  Seton Lake, inflow  100%  14  Anderson outflow  100%  15  Anderson Lake, middle  100%  Anderson Lake, West end  100%  Anderson Lake, inflow  n/a  95%  16 17  72  Table 3.2. Results of two-way ANOVA comparing blood biochemistry, energy and length between male and female sockeye salmon sampled immediately after capture from the fishway (‘control’) or sampled following 5-hour recovery period in a net-pen (‘net pen held’). Means (± SE), sample sizes and P-values are shown. Analyses were conducted on log10-transformed data for variables that did not initially meet model assumptions but untransformed means are presented. Male – Male Female – Female P-value Variable Control n Net pen held n Control n Net pen held n Holding Sex Interaction Cortisol 198.0 ± 23.5 11 216.2 ± 16.6 22 323.0 ± 31.9 6 389.9 ± 11.9 43 0.0599 <0.0001* 0.28 (ng/mL) Testosterone 9.98 ± 3.1 10 3.79 ± 2.09 22 22.9 ± 4.39 5 10.4 ± 1.51 42 <0.0001* 0.0006* 0.5 (ng/mL) Estradiol n/a 10 n/a 22 1.71 ± 0.27 5 1.48 ± 0.09 43 0.42 n/a n/a (ng/mL) Lactate 1.7 ± 0.27 11 1.3 ± 0.19 22 2.2 ± 0.37 6 1.9 ± 0.14 43 0.095 0.0354 0.74 (mmol/L) Glucose 4.42 ± 0.41 11 5.86 ± 0.29 22 4.89 ± 0.55 6 8.4 ± 0.21 43 <0.0001* 0.0003* 0.0063 * (mmol/L) Na+ 163.6 ± 2.43 11 162.2 ± 1.72 22 155.2 ± 3.29 6 157.2 ± 1.23 43 0.82 0.0035* 0.4 (mmol/L) K+ 2.54 ± 0.17 11 2.37 ± 0.12 22 3.81 ± 0.23 6 2.39 ± 0.087 43 <0.0001* 0.0005* 0.0006* (mmol/L) Cl134.1 ± 1.54 11 129 ± 1.09 22 130.3 ± 2.1 6 128.3 ± 0.78 43 0.038 0.1 0.23 (mmol/L) Osmolality 310.1 ± 3.03 11 303.8 ± 2.14 22 303.5 ± 4.1 6 307.1 ± 1.53 43 0.86 0.43 0.068 (mOsm/kg) GSE 5.62 ± 0.15 11 5.95 ± 0.11 21 6.49 ± 0.18 8 6.43 ± 0.078 43 0.33 <0.0001* 0.16 (MJ/kg) Length 62.1 ± 0.96 12 58.8 ± 0.68 22 59.8 ± 1.06 9 57.6 ± 0.47 45 0.0013* 0.03 0.5 (cm) Note: Values in bold text were significant at 0.05 and values marked by an asterisk were significant after Bonferroni correction (α =0.0005).  73  Table 3.3. Fate of Gates Creek sockeye salmon captured from Seton Dam Fishway and released either up- or downstream of the dam. Release site locations are shown in Figure 3.2. Data are not included for three sockeye released downstream of the dam that successfully ascended the fishway but descended while a gate was blocking the exit at the top of the fishway during sampling. Upstream of dam  Downstream of dam  Fate  #  %  #  %  Successful migrant  26  93  27  48  Failed in Anderson Lake  1  3.5  6  11  Failed in Seton Lake  1  3.5  4  7  Failed at fishway  n/a  10  18  Did not reach dam  n/a  8  14  1  2  Fishery removal  0  Total  28  0  56  74  Figure 3.1. Map of the Seton-Anderson watershed in Southwestern British Columbia, Canada showing the location of hydroelectric facilities on the Seton River and the spawning channel at Gates Creek. Numbers show the approximate location of acoustic telemetry receiver stations in the lakes. The locations of the 9 receivers in the Seton and Fraser rivers are shown in Figure 3.2.  75  Figure 3.2. Map of Seton River showing 4 release locations of telemetered sockeye salmon in 2007: Seton Lake near outlet (A), Seton River directly upstream of dam (B), lower Seton River at Cayoosh Creek (C), and powerhouse tailrace on the Fraser River (D). Numbers show the approximate location of acoustic telemetry receivers.  76  References Barton, B. A. 2002. Stress in fishes: A diversity of responses with particular references to changes in circulating corticosteroids. Integrative and Comparative Biology 42:517525. Beacham, T. D., M. Lapointe, J. R. Candy, K. M. Miller, and R. E. Withler. 2004. DNA in action: Rapid application of DNA variation to sockeye salmon fisheries management. Conservation Genetics 5:411-416. Bjornn, T. C., M. L. Keefer, C. A. Peery, K. R. Tolotii, R. R. Ringe, and P. J. Keniry. 2000. Migration of adult spring and summer Chinook salmon past Columbia and Snake river dams, through reservoirs and distribution into tributaries, 1996. Idaho Cooperative Fish and Wildlife Research Unit, Technical Report 2000-5, 146p. Bromaghin, J. F, T. J. Underwood, and R. F. Hander. 2007. Residual effects from fish wheel capture and handling of Yukon River fall chum salmon. North American Journal of Fisheries Management 27:860-872. Brown, R. S., D. R. Geist, and M. G. Mesa. 2006. Use of electromyogram telemetry to assess swimming activity of adult spring Chinook salmon migrating past a Columbia River dam. Transactions of the American Fisheries Society 135:281-287. Bunt, C. M., Cooke, S. J. and McKinley, R. S. 2000. Assessment of the Dunnville Fishway for passage of walleyes from Lake Erie to the Grand River, Ontario. Journal of Great Lakes Research 26:482-488. Calles, O. and L. Greenberg. 2009. Connectivity is a two-way street – the need for a holistic approach to fish passage problems in regulated rivers. River Research and Applications, in press. doi: 10.1002/rra.1228 Castro-Santos, T., A. Cotel, and P. W. Webb. 2009. Fishway evaluations for better bioengineering: An integrative approach. in A. Haro, K. L. Smith, R. A. Rulifson, C. M. Moffit, R. J. Klauda, M. J. Dadswell, R. A. Cunjak, J. E. Cooper, K. L. Beal, and T. S. Avery, editors. Challenges for diadromous fishes in a dynamic global environment. American Fisheries Society Symposium, Bethesda, MD (in press). Caudill, C. C., W. R. Daigle, M. L. Keefer, C. T. Boggs, M. A. Jepson, B. J. Burke, R. W. Zabel, T. C. Bjornn, and C. A. Peery. 2007. Slow dam passage in adult Columbia river salmonids associated with unsuccessful migration: Delayed negative effects of passage obstacles or condition-dependent mortality? Canadian Journal of Fisheries and Aquatic Sciences 64:979-995. Clay, C. H. 1995. Design of Fishways and Other Fish Facilities, 2nd edition. Lewis Publishers, Boca Raton.  77  Cooke, S. J., G. T. Crossin, D. A. Patterson, K. K. English, S. G. Hinch, J. L. Young, R. F. Alexander, M. C. Healey, G. Van Der Kraak, and A. P. Farrell. 2005. Coupling non-invasive physiological assessments with telemetry to understand inter-individual variation in behaviour and survivorship of sockeye salmon: Development and validation of a technique. Journal of Fish Biology 67:1342-1358. Cooke, S. J., S. G. Hinch, G. T. Crossin, D. A. Patterson, K. K. English, M. C. Healey, J. M. Shrimpton, G. Van Der Kraak, and A. P. Farrell. 2006. Mechanistic basis of individual mortality in Pacific salmon during spawning migrations. Ecology 87:1575-1586. Cooke, S. J., S. G. Hinch, A. P. Farrell, M. F. Lapointe, S. R. M. Jones, J. S. Macdonald, D. A. Patterson, M. C. Healey, and G. Van Der Kraak. 2004. Abnormal migration timing and high en route mortality of sockeye salmon in the Fraser River, British Columbia. Fisheries 29:22-33. Crossin, G. T., and S. G. Hinch. 2005. A nonlethal, rapid method for assessing the somatic energy content of migrating adult Pacific salmon. Transactions of the American Fisheries Society 134:184-191. Crossin, G. T., S. G. Hinch, S. J. Cooke, D. W. Welch, S. D. Batten, D. A. Patterson, G. Van Der Kraak, G. J. M. Shimpton, and A. P. Farrell. 2007. Physiology and behaviour of sockeye salmon homing through coastal waters to a natal river. Marine Biology 152:905-918. Crossin, G. T., S. G. Hinch, S. J. Cooke, D. W. Welch, D. A. Patterson, S. R. M. Jones, A. G. Lotto, R. A. Leggatt, M. T. Mathes, J. M. Shrimpton, G. Van der Kraak, and A. P. Farrell. 2008. Exposure to high temperature influences the behaviour, physiology, and survival of sockeye salmon during spawning migration. Canadian Journal of Zoology 86:127-140. Crossin, G. T., S. G. Hinch, A. P. Farrell, D. A. Higgs, A. G. Lotto, J. D. Oakes, and M. C. Healey. 2004. Energetics and morphology of sockeye salmon: Effects of upriver migratory distance and elevation. Journal of Fish Biology 65:788-810. Enders, E. C., C. J. Pennell, R. K. Booth, and D. A. Scruton. 2008. Energetics related to upstream migration of Atlantic salmon in vertical slot fishways. Canadian Technical Report of Fisheries and Aquatic Sciences 2800:v+22p. Fretwell, M. R. 1989. Homing behaviour of adult sockeye salmon in response to a hydroelectric diversion of homestream waters at Seton Creek. Bulletin No. XXV. International Pacific Salmon Fisheries Commission. Vancouver, BC, 38p.  78  Gilhousen, P. 1990. Prespawning mortalities of sockeye salmon in the Fraser River system and possible causal factors. Bulletin XXVI. International Pacific Salmon Fisheries Commission, Vancouver, BC. Gowans, A. R., J. D. Armstrong, I. G. Priede, and S. Mckelvey. 2003. Movements of Atlantic salmon migrating upstream through a fish-pass complex in Scotland. Ecology of Freshwater Fish 12:177-189. Hanson, K. C., M. A. Gravel, A. Graham, A. Shoji, and S. J. Cooke. 2008. Sexual variation in fisheries research and management: When does sex matter? Reviews in Fisheries Science 16:421-436. Hasler, C. T., L. B. Pon, D. W. Roscoe, B. Mossop, D. A. Patterson, S. G. Hinch, and S. J. Cooke. 2009. Expanding the “toolbox” for studying the biological responses of individual fish to hydropower infrastructure and operating strategies. Environmental Reviews 17:179-197. Hinch, S. G., and J. Bratty. 2000. Effects of swim speed and activity pattern on success of adult sockeye salmon migration through an area of difficult passage. Transactions of the American Fisheries Society 129:598-606. Hinch, S. G., S. J. Cooke, M. C. Healey, and A. P. Farrell. 2006. Behavioral physiology of fish migrations: Salmon as a model approach. Pages 239-295 in K. Sloman, S. Balshine, and R. Wilson, editors. Fish physiology volume 24: Behavior and physiology of fish. Elsevier Press, New York, NY. Hinch, S. G., and P. S. Rand. 1998. Swim speeds and energy use of upriver-migrating sockeye salmon (Oncorhynchus nerka): Role of local environment and fish characteristics. Canadian Journal of Fisheries and Aquatic Sciences 55:1821-1831. Houston, A. H. 1990. Blood and circulation. in C. B. Shreck, and P. B. Moyle, editors. Methods for fish biology. American Fisheries Society, Bethesda, MD. Jolly, G. M. 1982. Mark recapture models with parameters constant in time. Biometrics 38:301-321. Karppinen, P., T. Maekinen, J. Erkinaro, V. Kostin, R. Sadkovskij, A. Lupandin, and M. Kaukoranta. 2002. Migratory and route-seeking behaviour of ascending Atlantic salmon in the regulated river Tuloma. Hydrobiologia 483:23-30. Keefer, M. L., Peery, C. A., Bjornn, T. C., Jepson, M. A., and Stuehrenberg, L. C. 2004. Hydrosystem, dam and reservoir passage rates of adult Chinook salmon and steelhead in the Columbia and Snake rivers. Transactions of the American Fisheries Society 133:1413-1439.  79  Keefer, M. L., Peery, C. A., Heinrich, M. J. and Bjornn, T. C. 2008. Behavior and survival of radio-tagged sockeye salmon during adult migration in the Snake and Salmon rivers. Idaho Cooperative Fish and Wildlife Research Unit, Technical Report 2008-6, 16 pp. Kubokawa, K., T. Watanabe, M. Yoshioka, and M. Iwata. 1999. Effects of acute stress on plasma cortisol, sex steroid hormone and glucose levels in male and female sockeye salmon during the breeding season. Aquaculture 172:335-349. Lundqvist, H., P. Rivinoja, K. Leonardsson, and S. McKinnell. 2008. Upstream passage problems for wild Atlantic salmon (Salmo salar L.) in a regulated river and its effect on the population. Hydrobiologia 602:111-127. Macdonald, J. S. 2000. Mortality during the migration of Fraser River sockeye salmon (Oncorhynchus nerka): A study of the effect of ocean and river environmental conditions in 1997. Canadian Technical Report of Fisheries and Aquatic Sciences 2315. Macdonald, J. S., M. G. G. Foreman, T. Farrell, I. V. Williams, J. Grout, A. Cass, J. C. Woodey, H. Enzenhofer, W. C. Clarke, R. Houtman, E. M. Donaldson, and D. Barnes. 2000. The influence of extreme water temperatures on migrating Fraser River sockeye salmon (Oncorhynchus nerka) during the 1998 spawning season. Canadian Technical Report of Fisheries and Aquatic Sciences 2326. Macdonald, G. and L. Milligan. 1997. Ionic, osmotic and acid-base regulation in stress. Pages 119-145 In G. K. Iwama, J. Sumpter, A. Pickering, and C. B. Schreck, editors. Fish Stress and Health in Aquaculture Seminar Series 62, Cambridge University Press, Cambridge. Mazeaud, M. M., F. Mazeaud, and E. M. Donaldson. 1977. Primary and secondary effects of stress in fish: Some new data with a general review. Transactions of the American Fisheries Society 106: 201-212. Milligan, C. L., G. B. Hooke, and C. Johnson. 2000. Sustained swimming at low velocity following a bout of exhaustive exercise enhances metabolic recovery in rainbow trout. Journal of Experimental Biology 203:921-926. Nadeau, P. S., S. G Hinch, K. A. Hruska, L. B. Pon, and D. A. Patterson. 2009. The effects of experimentally altered water velocity on physiological condition and survival of adult sockeye salmon (Oncorhynchus nerka) during spawning migration. Environmental Biology of Fishes, in press. Naughton, G. P., C. C. Caudill, M. L. Keefer, T. C. Bjornn, L. C. Stuehrenberg, and C. A. Peery. 2005. Late-season mortality during migration of radio-tagged adult sockeye salmon (Oncorhynchus nerka) in the Columbia River. Canadian Journal of Fisheries and Aquatic Sciences 62:30-47.  80  Nehlsen, W., J. E. Williams, and J. A. Lichatowich. 1991. Pacific salmon at the crossroads: Stocks at risk from California, Oregon, Idaho, and Washington. Fisheries 16(2):4-21. Nielsen, M., L., Boesgaard R. M., Sweeting, B. A. McKeown, and P. Rosenkilde. 1994. Plasma levels of lactate, potassium, glucose, cortisol, growth hormone and triiodo-Lthyronine in rainbow trout (Oncorhynchus mykiss) during exercise at various levels for 24 h. Canadian Journal of Zoology 72: 1643-1647. Patterson, D. A., J. S. Macdonald, S. G. Hinch, M. C. Healey, and A. P. Farrell. 2004. The effect of exercise and captivity on energy partitioning, reproductive maturation and fertilization success in adult sockeye salmon. Journal of Fish Biology 64:10391059. Patterson, D. A., J. S. Macdonald, K. M. Skibo, D. P. Barnes, I. Guthrie, and J. Hills. 2007. Reconstructing the summer thermal history for the lower Fraser River, 1942 to 2006, and implications for adult sockeye salmon (Oncorhynchus nerka) spawning migration. Canadian Technical Report of Fisheries and Aquatic Sciences 2724:vii+43p. Pelicice, F. M. and A. A. Agostinho. 2008 Fish-passage facilities as ecological traps in large neotropical rivers. Conservation Biology 22:180-188. Pon, L. B., S. G. Hinch, S. J. Cooke, D. A. Patterson, and A. P. Farrell. 2009a. A comparison of the physiological condition of migrant adult sockeye salmon and their attraction into the fishway at Seton River dam, British Columbia under three operational water discharge rates. North American Journal of Fisheries Management, in press. Pon, L. B., S. G. Hinch, S. J. Cooke, D. A. Patterson, and A. P. Farrell. 2009b. Physiological, energetic and behavioural correlates of successful fishway passage of adult sockeye salmon (Oncorhynchus nerka) in the Seton River, British Columbia. Journal of Fish Biology 74:1323-1336. Pon, L. B., Cooke, S. J., Hinch, S. G. 2006. Passage Efficiency and Migration Behaviour of Salmonid Fishes at the Seton Dam Fishway. Final Report for the Bridge Coastal Restoration Program, Project 05.Se.01, 105p. Portz, D. E., C. M. Woodley, and J. J. Cech Jr. 2006. Stress-associated impacts of shortterm holding on fishes. Reviews in Fish Biology and Fisheries 16:125-170. Quinn, T. P. 2005. The behavior and ecology of Pacific salmon and trout. American Fisheries Society, Bethesda, Maryland.  81  Roscoe, D. W. and S. G. Hinch, 2009. Effectiveness monitoring of fish passage facilities: historical trends, geographic patterns and future directions. Fish and Fisheries, in press. Schilt, C. S. 2007. Developing fish passage and protection at hydropower dams. Applied Animal Behavior Science 104:295-325. Scruton, D. A., C. J. Pennell, C. E. Bourgeois, R. F. Goosney, T. R. Porter, and K. D. Clarke. 2007. Assessment of a retrofitted downstream fish bypass system for wild Atlantic salmon (Salmo salar) smolts and kelts at a hydroelectric facility on the Exploits River, Newfoundland, Canada. Hydrobiologia 582:155-169. Slaney, T. L., K. D. Hyatt, T. G. Northcote, and R. J. Fielden. 1996. Status of anadromous salmon and trout in British Columbia and Yukon. Fisheries 21(10):2032. Thorstad, E. B., F. Okland, F. Kroglund, and N. Jepsen. 2003. Upstream migration of Atlantic salmon at a power station on the River Nidelva, Southern Norway. Fisheries Management and Ecology 10:139-146. Van Ginneken, V., R. Boot, T. Murk, G. Van den Thillart, and P. Balm. 2004. Blood plasma substrates and muscle lactic-acid response after exhaustive exercise in common carp and trout: Indications for a limited lactate-shuttle. Animal Biology 54:119-130. Wedemeyer, G. A., and R. S. Wydoski. 2008. Physiological response of some economically important freshwater salmonids to catch-and-release fishing. North American Journal of Fisheries Management 28:1587-1596. Welch, D. 2007. Final Report: Investigations to determine the cause of early entry migration behavior for adult Late-run Fraser River sockeye (Kintama Component). Report to Southern Boundary Restoration and Enhancement Fund. Pacific Salmon Commission, Vancouver, BC. Young, J. L., S. G. Hinch, S. J. Cooke, G. T. Crossin, D. A. Patterson, A. P. Farrell, G. Can Der Kraak, A. G. Lotto, A. Lister, M. C. Healey, and K. K. English. 2006. Physiological and energetic correlates of en route mortality for abnormally early migrating adult sockeye salmon (Oncorhynchus nerka) in the Thompson River, British Columbia. Canadian Journal of Fisheries and Aquatic sciences 63:10671077. Zar, J. 1999. Biostatistical analysis, 4th edition. Prentice Hall, Englewood Cliffs, New Jersey.  82  CHAPTER 4: The effect of dam spill discharge on attraction of sockeye salmon into the Seton Dam Fishway, British Columbia.  Introduction Fishways have the potential to re-establish connectivity in watersheds obstructed by dams and other anthropogenic barriers. For migratory species whose spawning areas lie upstream of dam, safe and timely passage of an obstruction is necessary to complete their life-history and successfully reproduce. For this reason, many fishways have been specifically designed for migratory anadromous salmon (Clay, 1995). However, a growing body of literature suggests that many fishways do not perform as well as expected. For instance, some fish fail to pass fishways and those that do may pass incur long delays, which are likely to incur fitness costs (Castro-Santos et al., 2009). Passage failure or delay at fishways is often attributed to inability of fish to locate the entrance (Williams, 1998; Bunt, 2001; Karpinnen, 2002). The proportion of fish that are able to locate the entrance, often called the attraction efficiency, is highly dependent on local hydraulics (Leman and Paulik, 1966; Bunt et al., 1999; Larinier, 2002). Upstream migrating fish are typically attracted to the highest water velocities (Banks, 1969) but the amount of water emanating from a fishway is typically a small fraction of the total discharge of a dam. In these cases, fish may be attracted to the areas of higher discharge and velocity and suffer long delays before locating the fishway entrance (Jensen and Aass, 1995; Thorstad et al., 2003; Lundqvist et al., 2008). For this reason, many fishways have ‘attraction’ flows discharged near the entrance. On the other hand, if discharge near the fishway is too high, fish may be unable to swim through the fast or turbulent flows (Castro-Santos, 2004) or may volitionally avoid them (Cotel et al., 2006), and therefore access will be compromised (Bunt, 2001). Furthermore, water discharged through or near fishways at hydroelectric dams is typically not able to be utilized for power production and therefore, attraction flows may come at a high financial cost. Clearly, identifying discharges at dams and fishways that are optimal for fish passage is crucial to reduce the impact of barriers and make efficient use of water resources. 83  However, the vast majority of fishways have not been evaluated in terms of how spill discharge affects efficiency and rates of passage (Roscoe and Hinch, 2009). A recent study of Gates Creek sockeye salmon (Oncorhynchus nerka) in the Seton River, a tributary of the Fraser River in British Columbia, Canada, examined physiological stress levels and passage behaviour during three levels of water discharge from the dam (Pon et al., 2009a). Neither physiological stress levels nor attraction efficiency varied with discharge but fish delayed in the tailrace below the dam for significantly longer at an intermediate discharge level. During the course of subsequent study at Seton dam assessing post-passage consequences on survival of sockeye salmon (Chapter 3), discharge levels were more than double what they were during Pon et al.’s (2009a) study (35-60 m3/s vs. 11-15 m3/s). Because handling and tracking of fish, and environmental conditions along the migratory route (e.g. temperature) were otherwise very similar during the two years of study, the much higher spill discharges in 2007 provided an opportunity to extend Pon et al.’s (2009a) findings and assess fishway entrance delay and attraction efficiency over a broad range of operational spill discharges.  Pon et al. (2009a) found that flow patterns at intermediate discharge (12.5  m3/s) resulted in longer entrance delay compared to higher (15 m3/s) or lower (11 m3/s) discharges. We predicted that much higher discharges of 35 and 60 m3/s would result in progressively longer delays because fish would avoid the high velocities and turbulent flow caused by high discharges. Further, because of the energy and time costs of delay, we predicted that the longer delays during high discharge would be associated with lower attraction efficiencies. The objective of this study is to synthesize two years of research concerning fishway entrance and passage behaviour in order to guide future adaptive management experiments and inform operational procedures at Seton Dam Fishway.  Methods Study Site We studied the Gates Creek population of sockeye salmon at the Seton River dam and fishway, 5 km from Lillooet, in Southwestern, British Columbia, Canada. As adults, this population migrates from the Pacific Ocean 320 km up the Fraser River before  84  reaching the Seton River. Migrants then travel upstream ~60 km through the Seton River, Seton Lake and Anderson Lake before reaching spawning areas in Gates Creek near D’Arcy, BC. The Seton River Dam is located 4.4 km upstream of the Fraser River and 760 m downstream of Seton Lake (Figure 4.1). A portion of the flow of the Seton River is diverted into a 3.8 km long canal that delivers water to the hydroelectric power station on the Fraser River, 1.2 km downstream of the Seton River. A vertical-slot fishway on the river right bank allows passage of fish over the Seton dam (Figure 4.1). The fishway consists of 32 pools, is 107 m long and has an overall grade of 6.9%. Discharge through the fishway is 1.3 m3/s throughout the year. Flow in the Seton River is maintained by discharges from the fishway and dam with minimum flow requirements of 11.3 m3/s during salmon migration (Andrew and Geen, 1958). Water is spilled at the dam through a sluice gate adjacent to the fishway entrance (the ‘fish-water sluice’), which is intended to attract fish to the fishway, and through any of five siphons. All dam operations and spill discharges are controlled by BC Hydro. In 2005, discharge from the dam was 15.8 m3/s from 10-22 August, 12.7 m3/s from 23 August to September 5, and 11.0 m3/s from 6-23 September. For all three discharge levels the entire volume was discharged through the fish-water sluice. In 2007, discharge from the dam was 60 m3/s from 15-20 August and 35 m3/s from 21-31 August. During the discharge of 60 m3/s water was discharged from the fish-water sluice (~15 m3/s), the siphon adjacent to the sluice (20 m3/s) and the fifth siphon, which is furthest from the sluice (25 m3/s). During the discharge of 35m3/s the fifth siphon was turned off. Water temperature in the Seton River was measured using archival temperature loggers (iButton Thermochrons, DS1921Z, Maxim Integrated Products, Inc., Sunnyvale, CA). Water temperature in the Fraser River was obtained from the Fisheries and Oceans Canada.  85  Fish capture, handling and tagging Methods of fish capture, handling and telemetry are detailed in Pon et al. (2009a) and Chapter 3 of this thesis, and are summarized here. All fish were captured by dip-net from the top pool of the fishway. Tagging procedures were identical in the two years of study. Fish were restrained in v-shaped trough lined with foam and supplied continuously with fresh river water and tagging was completed without the use of anaesthetic. A blood sample was drawn from the caudal vein for subsequent analysis of the physiological status of fish; these results are presented elsewhere (Pon et al., 2009a,b; Chapters 3 and 5 of this thesis). Fork length was measured to the nearest 5 mm. A small tissue sample was removed from the adipose fin using a hole punch and stored in ethanol for subsequent DNA analysis to confirm population of origin (Beacham et al., 1995, 2004). Fish were marked with an external tag (FT-4 Cinch up, Floy Tag Inc., Seattle, WA) attached through the dorsal musculature immediately anterior to the dorsal fin using a hollow needle. A telemetry transmitter was inserted gastrically using a tag applicator consisting of a hollow plastic tube and plunger to expel the tag. Radio-telemetry transmitters (Lotek Wireless, Newmarket, Ontario) were used in 2005 whereas acoustic telemetry transmitters (V16-1H-R64K coded pingers, Vemco Inc., Shad Bay, NS) were used in 2007.  Tracking Fish movements were tracked using radio telemetry in 2005 and acoustic telemetry in 2007. Both methods allowed accurate estimates of delay prior to entering the fishway and attraction efficiency making results comparable between years. Radiotagged fish were tracked manually using portable telemetry receivers (model SRX_400, Lotek Wireless, Newmarket, Ontario) and three-element Yagi antennas. The area between the top of the fishway and 1 km downstream of the dam was monitored continuously between 0700 and 1800 h each day. At night, fixed radio telemetry receivers were placed at the entrance and exit of the fishway to detect entry and ascent. Because there were no radio receivers upstream of the dam, detection efficiencies could not be calculated, but detection of radio-tags with both manual and fixed radio receivers was very good and it is unlikely that any fish were able to pass the fishway undetected.  86  In 2007, behaviour of acoustic-tagged fish was monitored using a fixed array of acoustic telemetry receivers (VR2, Vemco Inc., Shad Bay, NS). Acoustic receivers were positioned at the entrance, half-way point, and exit of the fishway. Two acoustic receivers in the Seton River approximately 15 m and 80 m downstream of the dam face detected fish in the tailrace of the dam. There were also acoustic receivers upstream of the dam in the Seton River and near the mouth of Seton Lake, which allowed us to calculate detection efficiencies for the fishway receivers. Fish were released ~60 m downstream of the dam in 2005. In 2007, fish were released further downstream, either into the Seton River 1.3 km downstream of the dam, or into the Fraser River 1.2 km downstream of the Seton River, a distance of 5.5 km from the dam. The release sites in 2007 were chosen in order to monitor migration through the lower Seton River as part of a study examining migration behaviour and mortality in the watershed. After transportation to the release site by truck, fish were held in net-pens in the river for 5 hours to recover from transportation-related stress before they were released. Comparisons with a group of control fish that were not transported indicated that transportation and net-pen holding had no effect on behaviour or survival (Chapter 3).  Data analysis Attraction efficiency was calculated as the percentage of fish present in the area below the dam that entered the fishway. Entrance delay was calculated from the time fish were first detected in the tailrace of the dam (i.e. the time of release in 2005 and the first detection on one of the receivers downstream of the dam in 2007) until entry into the fishway. Delay was compared among levels of discharge using analysis of variance (ANOVA), followed by Tukey’s post-hoc test to determine which pairs of discharges differed. Delay values were square root transformed before analysis in order to meet model assumptions of normality and homoscedasticity. Delay was also compared between males and females using ANOVA. Differences in attraction efficiency among  87  the discharge levels were assessed using Fisher’s exact test. A significance level of 0.05 was used for all tests. Analyses were carried out in SAS v.9.1.3 (SAS Inc., Cary, N.C.).  Results Temperatures (mean daily averages) in the Seton River ranged from 14.5-16.2˚C across the three discharge periods in 2005. Seton River temperatures were similar in 2007, with averages of 14.4˚C and 14.1˚C during the discharges of 35 m3/s and 60 m3/s, respectively. Fraser River temperature was similar in both study years, ranging from 1319˚C during the 2005 study period and 16-18˚C during the 2007 period, both of which are close to long-term averages (Patterson et al., 2007). DNA analysis indicated that all sockeye salmon were from the Gates Creek population, except for one fish in 2007, which was removed from all analyses. Detection efficiency of the acoustic receiver array was high (>90% for each individual receiver; Chapter 3) indicating that it was unlikely that fish passed through the tailrace or fishway undetected. Fourteen fish never reached the tailrace of the Seton dam after being released in the Seton and Fraser rivers in 2007, and therefore provided no data on fishway passage behaviour. In 2005, radio tracking using a combination of manual searching and fixed location receivers provided excellent coverage of the study area. Because there were no receivers upstream of the fishway detection efficiency could not be calculated but it is unlikely that any fish passed undetected. Two fish released at flow of 15.8 m3/s in 2005 were excluded from the analysis of fishway entrance delay. One fish was excluded because it was the only fish to fall back immediately after release and not return to the dam area until several days later and the other passed the fishway without being detected (Pon et al., 2009a). Entrance delay was significantly different among discharges (F4,54=3.34, P=0.016; Figure 4.2). Tukey’s tests indicated that delay at 60 m3/s was significantly greater than delay at 35 m3/s, 15.8 m3/s and 11.0 m3/s, whereas all other comparisons were not significant. However, we note that previous analysis of delay at the lower three discharges using untransformed data found that delay was significantly greater at 12.5  88  m3/s than at 11.0 m3/s or 15.8 m3/s (Pon et al., 2009a). Delay did not differ between males and females in 2007 (P=0.6) or in 2005 (P=0.15). Attraction efficiency differed significantly among discharges (P=0.036) ranging from 40% at 60 m3/s to 100% at 12.5 m3/s. However, the relationship between attraction efficiency and discharge did not appear to be simple linear trend (Figure 4.2). Despite large differences in the magnitude of passage efficiencies at the various discharge levels, of all the pair-wise comparisons, only 60 m3/s and 35 m3/s differed significantly (P=0.03). During the high discharges in 2007 (35 m3/s and 60 m3/s) a greater proportion of females failed to enter the fishway (9 of 35, 26%) compared to males (1 of 16; 4%) although the difference was not statistically different (P=0.14). There were no sex differences in attraction efficiency during the lower flows (11-15.8 m3/s) in 2005 (Pon et al., 2009a). Discharge within the fishway was 1.3 m3/s during both years of study. In 2005 all fish that entered the fishway successfully ascended the entire length. Passage efficiency for fish that entered the fishway was also high in 2007 (93%) although a few fish did not reach the top and fell back downstream. Mean time to ascend the fishway was less than an hour in both years (Pon et al., 2006; Roscoe and Hinch, 2007).  Discussion In order to inform design or operational changes that could improve the effectiveness of fishways, there is a need to study how water discharge or other environmental factors affect fishway passage (Roscoe and Hinch, 2009). We opportunistically took advantage of the wide range of discharge conditions at the Seton dam in order to assess their effect on fishway passage behaviour of sockeye salmon. Because we did not control discharge from the dam in our studies, there were small and uneven sample sizes across discharge groups, which hindered statistical analyses and limited the conclusions we could draw. Despite this limitation, we were able to assess passage behaviour and success over a broad range of discharge conditions, which had not previously been done at Seton dam, and has rarely been done elsewhere.  89  Because discharges were different and not overlapping in the two study years, we needed to assess other factors that could potentially alter passage behaviour and confound the effects of discharge. Several lines of evidence suggest that results are comparable across the two years. Prior to reaching the Seton River, Gates Creek sockeye migrated ~320 km up the Fraser River, which comprises the majority of their freshwater migration. In the Fraser River, water temperature is known to be a critical factor governing physiological condition, behaviour and mortality of sockeye salmon migrants (Gilhousen, 1990; Crossin et al., 2008; Farrell et al., 2008; Keefer et al., 2008). In both study years, Fraser water temperatures were near long-term averages (Patterson et al., 2007) and below levels that are known to cause stress (Mathes et al., in press), slowed migration (Goniea et al., 2006) or high mortality (Keefer et al., 2008). That migration conditions were favourable and not stressful in both study years is consistent with physiological biopsies taken from telemetered fish. In both years, fish had similar levels of somatic energy reserves and indices of stress measured from blood samples (e.g. plasma cortisol, lactate, and ion concentrations) suggested that fish were not stressed or anaerobically exhausted (Pon et al., 2009a; Chapter 3 of this thesis; Roscoe and Hinch, 2007). Finally, mean water temperature in the Seton River was similar between years, ranging from 14.1-14.4˚C in 2007 and 14.5-16.5˚C in 2005. The temperature variation of a few degrees in the Seton River in 2005 was found to have no effect on passage behaviour at Seton dam (Pon et al., 2009a). Thus, because water temperature in the Seton and Fraser rivers likely did not influence passage behaviour differently between study years, and fish were in good physiological condition in both years, we contend that differences in fishway passage behaviour were primarily due to operational changes in spill discharge from the dam. Water discharge from the dam had a significant effect on both the attraction efficiency and delay in locating and entering the fishway. Delay was significantly greater at the highest discharge compared to all other discharge levels, which was consistent with our prediction of longer delays at higher flows. The fact that two fish had delays of several days at 60 m3/s suggests that access to the fishway entrance is impeded at very  90  high flows. This notion is also supported by observations of untagged sockeye approaching the visibly turbulent tailrace of the dam during the highest discharge, and swimming rapidly to maintain position in the current before falling back into calmer waters downstream (pers. obs., D. Roscoe). However, in contrast to our prediction, delays were not longer during the second highest discharge (35 m3/s) compared to the lower discharge levels. Thus, a discharge of 35 m3/s at Seton dam, which is approximately triple the minimum required discharge during the migration season, did not create fast enough velocities, turbulence or other hydraulics that impeded access to the fishway entrance. Instead, delays were longer at an intermediate discharge of 12.5 m3/s compared to lower (11.0 m3/s) and higher (15.8, 35.0 m3/s) flows although this difference was only statistically significant in Pon et al.’s (2009a) study and not in the present study which needed to transform data. Pon et al. (2009a) speculated that longer delays were caused by complex flows and turbulence that were unique to the intermediate discharge but studies quantifying hydraulic patterns in the tailrace are needed to test this hypothesis. Values of attraction efficiency varied widely across the discharges. However, most of the differences in attraction efficiency between pairs of discharge levels were not significantly different, even in cases where the magnitude of the difference was large. For instance, the difference between 40% at 60 m3/s and 100% at 12.5 m3/s was not significantly different. Clearly, small sample sizes and an unbalanced design limited our ability to detect potential differences in attraction efficiency. Nevertheless, one result that is clear, despite a small sample size, is that the highest discharge resulted in poor attraction efficiency with only two of five fish passing during the discharge of 60 m3/s. Efficiencies at the other four discharges, ranging from 63% to 100%, were not statistically different. Thus, it may be that the percentage of sockeye that pass the fishway is not greatly affected by discharges between 11 and 35 m3/s, although the time required to locate and enter the fishway will vary. However, because of the small numbers of fish involved it is possible we were simply unable to detect differences in attraction efficiency within this range (i.e. a type II error).  91  We found that failure of sockeye salmon to pass the Seton Fishway was mostly associated with locating the entrance and not with passage of the fishway itself. Very few fish that successfully entered the fishway failed to ascend the entire length. Ascent times of less than an hour further suggest that fishway passage is not difficult for sockeye salmon. Discharge inside the fishway did not change throughout the year and ascent time was not different across spill discharges into the tailrace (Pon et al., 2009a). Our study at Seton dam also revealed possible sex differences in success in entering the fishway, but only at the higher discharge levels. Attraction efficiency was lower in females (74%) compared to males (94%) during the two highest discharges whereas attraction efficiency did not differ between genders at discharges between 11 m3/s and 15.8 m3/s. Though striking, the difference in attraction efficiency at the highest flows was not statistically different, possibly because of the conservative nature of the Fisher’s exact test. If females are in fact less successful than males at locating and entering the fishway during high discharges, it may be because of sex differences in swimming behaviour and energetics. Relative to females, male sockeye salmon swim at faster speeds and use more energy per distance travelled (Hinch and Rand, 1998). Stronger selection for energetically efficient swimming behaviours likely exists in female sockeye because they invest considerably more energy in gonad development than do males (Crossin et al., 2004) and therefore may be at greater risk of exhausting energy reserves before spawning (Hinch and Rand, 1998). However, we speculate that in areas of fast and turbulent flow, such as fishways, tailraces or natural river constrictions, the use of slower swim speeds by females reduces the chances of passing the hydraulically challenging reach. This hypothesis is consistent with observations of a greater proportion of females compared to males failing to pass Hell’s Gates, a constricted area of the Fraser River Canyon characterized by fast and turbulent flows (Gilhousen, 1990). The possibility that passage failure at the fishway during high flows may be greater for females than males has important implications for conservation since total spawning success of a population is governed primarily by female success whereas a loss of males has little effect on subsequent generations (Gilhousen, 1990).  92  Originally, we predicted that longer delays would be associated with poorer attraction efficiencies. Supporting this idea is the observation of long delays and poor attraction efficiency at the highest discharge. However, there did not appear to be simple relationships between discharge, attraction and delay. For instance, fish were delayed below the dam for longer at 12.8 m3/s compared to 11.0 m3/s and 15.8 m3/s, but attraction efficiency was the highest at this intermediate discharge, since all fish successfully entered the fishway. The relationships between discharge, fishway attraction and delay may not have been linear because of flow patterns created by different discharges. Migrating Pacific salmon (Oncorhynchus spp.) are negatively rheotactic and orient into the current but complex or turbulent flow patterns may disrupt directional cues and cause delay (Hinch and Rand 1998; Hinch et al., 2006). Turbulence can increase the energetic costs of swimming and fish may avoid these types of flows (Hinch and Rand 1998; Enders et al., 2003). Thus, optimum attraction at the fishway may rely on a spill discharge that provides adequate attraction flows and suitable directional cues for migrating salmon. Because only a few discharges were examined in our studies and sample sizes were small for several of the flows, it is not possible to say what level of discharge results in the highest fishway attraction at Seton dam. But our results suggest that delay and attraction are highly dependent on discharge and point to the need to quantify local hydraulics at various discharges and how these affect fishway attraction. Because of the unique nature of fishways, it is important that each facility is evaluated in order to understand passage failure and inform mitigation measures that would improve fishway effectiveness. We recommend that future studies at Seton dam adopt an adaptive management approach, manipulating both the volume of discharge and the locale of water release from various siphons and sluices. If hydraulic and biological parameters are reported in detail then these results can be used not only for local mitigation measures but will also help elucidate factors which govern passage performance and thus be applicable to fishways elsewhere (Castro-Santos et al., 2009).  93  Figure 4.1. Map showing the Seton-Anderson watershed and the location of the Seton Dam near Lillooet, British Columbia, Canada where sockeye salmon tagged with telemetry transmitters were tracked to study passage behaviour in 2005 and 2007. Insets show the location of the study site in Canada (upper left) and details of the layout of Seton dam and fishway (bottom right). At the dam, water is discharged through the fish water sluice to attract fish to the fishway entrance and additional spill is discharged through the siphons. Water used for hydroelectric power generation is diverted into a canal south of the fishway (not shown). Inset figure of dam and fishway adapted from Pon et al. (2009a) with permission.  94  Figure 4.2. The percentage of individuals that successfully entered the fishway, called the attraction efficiency (black circles), and the mean delay (± S.E.; white circles) below the dam before entering for sockeye salmon at the Seton Dam in British Columbia, Canada. Numbers next to each value are sample sizes.  95  References Andrew, F. J. and G. H. Geen. 1959. Sockeye and pink salmon investigations at the Seton Creek hydroelectric installation. International Pacific Salmon Fisheries Commission Progress Report No. 4. Banks, J.W. 1969. A review of the literature on the upstream migration of adult salmonids. Journal of Fish Biology 1:85-136. Beacham, T. D., R. E. Withler, and C. C. Wood. 1995. Stock identification of sockeye salmon by means of minisatellite DNA variation. North American Journal of Fisheries Management 15:249-265. Beacham, T. D., M. Lapointe, J. R. Candy, K. M. Miller, and R. E. Withler. 2004. DNA in action: Rapid application of DNA variation to sockeye salmon fisheries management. Conservation Genetics 5:411-416. Bunt, C. M. 2001. Fishway entrance modifications enhance fish attraction. Fisheries Management and Ecology 8:95-105. Bunt, C. M., B. T. van Poorten, and L. Wong. 2001. Denil fishway utilization patterns and passage of several warmwater species relative to seasonal, thermal and hydraulic dynamics. Ecology of Freshwater Fish 10:212-219. Castro-Santos, T., A. Cotel, and P. W. Webb. 2009. Fishway evaluations for better bioengineering: An integrative approach. in A. Haro, K. L. Smith, R. A. Rulifson, C. M. Moffit, R. J. Klauda, M. J. Dadswell, R. A. Cunjak, J. E. Cooper, K. L. Beal, and T. S. Avery, editors. Challenges for diadromous fishes in a dynamic global environment. American Fisheries Society Symposium, Bethesda, MD (in press). Castro-Santos, T. 2004. Quantifying the combined effects of attempt rate and swimming capacity on passage through velocity barriers. Canadian Journal of Fisheries and Aquatic Sciences 61:1602-1615. Clay, C. H. 1995. Design of fishways and fish facilities, 2nd edition. Lewis Publishers, Boca Raton, FL. Cotel, A. J., P. W. Webb, and H. Tritico. 2006. Do brown trout choose locations with reduced turbulence? Transactions of the American Fisheries Society 135:610-619. Crossin, G. T., S. G. Hinch, S. J. Cooke, D. W. Welch, D. A. Patterson, S. R. M. Jones, A. G. Lotto, R. A. Leggatt, M. T. Mathes, J. M. Shrimpton, G. Van der Kraak, and A. P. Farrell. 2008. Exposure to high temperature influences the behaviour, physiology, and survival of sockeye salmon during spawning migration. Canadian Journal of Zoology 86:127-140.  96  Crossin, G. T., S. G. Hinch, A. P. Farrell, D. A. Higgs, A. G. Lotto, J. D. Oakes, and M. C. Healey. 2004. Energetics and morphology of sockeye salmon: Effects of upriver migratory distance and elevation. Journal of Fish Biology 65:788-810. Dominy, C. L. 1973. Effect of entrance-pool weir elevation and fish density on passage of alewives (Alosa pseudoharengus) in a pool and weir fishway. Transactions of the American Fisheries Society 102, 398-404. Enders, E. C., D. Boisclair, A. G. Roy. 2003. The effect of turbulence on the cost of swimming for juvenile Atlantic salmon (Salmo salar). Canadian Journal of Fisheries and Aquatic Sciences 60: 1149-1160. Farrell, A. P., S. G. Hinch, S. J. Cooke, D. A. Patterson, G. T. Crossin, M. Lapointe, and M. T. Mathes. 2008. Pacific salmon in hot water: applying aerobic scope models and biotelemetry to predict the success of spawning migrations. Physiological and Biochemical Zoology 81:697-708. Gilhousen, P. 1990. Prespawning mortalities of sockeye salmon in the Fraser River system and possible causal factors. Bulletin XXVI. International Pacific Salmon Fisheries Commission, Vancouver, BC. Goniea, T. M., M. L. Keefer, T. C. Bjornn, C. A. Peery, D. H. Bennett, and L. C. Stuehrenberg. 2006. Behavioral thermoregulation and slowed migration by adult fall Chinook salmon in response to high Columbia River water temperatures. Transactions of the American Fisheries Society 135:408-419. Hinch, S. G., S. J. Cooke, M. C. Healey, and A. P. Farrell. 2006. Behavioral physiology of fish migrations: Salmon as a model approach. Pages 239-295 in K. Sloman, S. Balshine, and R. Wilson, editors. Fish physiology volume 24: Behavior and physiology of fish. Elsevier Press, New York, NY. Hinch, S. G., and P. S. Rand. 1998. Swim speeds and energy use of upriver-migrating sockeye salmon (Oncorhynchus nerka): Role of local environment and fish characteristics. Canadian Journal of Fisheries and Aquatic Sciences 55:1821-1831. Jensen, A. J. and P. Aass. 1995. Migration of a fast-growing population of brown trout (Salmo trutta L.) through a fish ladder in relation to water flow and water temperature. Regulated Rivers-Research & Management 10:217-228. Karppinen, P., T. Maekinen, J. Erkinaro, V. Kostin, R. Sadkovskij, A. Lupandin, and M. Kaukoranta. 2002. Migratory and route-seeking behaviour of ascending Atlantic salmon in the regulated river Tuloma. Hydrobiologia 483:23-30. Keefer, M. L., C. A. Peery, and M. J. Heinrich. 2008. Temperature-mediated en route migration mortality and travel rates of endangered Snake River sockeye salmon. Ecology of Freshwater Fish 17:136-145.  97  Larinier, M. 2002. Location of fishways. Bulletin Francais de la Peche et de la Pisciculture 364:39-53. Leman, B. and G. J. Paulik. 1966. Spill pattern manipulation to guide migrant salmon upstream. Transactions of the American Fisheries Society 95:397-407. Lundqvist, H., P. Rivinoja, K. Leonardsson, and S. McKinnell. 2008. Upstream passage problems for wild Atlantic salmon (Salmo salar L.) in a regulated river and its effect on the population. Hydrobiologia 602:111-127. Mathes, M. T., S. G. Hinch, S. J. Cooke, Crossin, G. T., D. A. Patterson, A. G. Lotto, and A. P. Farrell. 2009. Effect of water temperature, timing, physiological condition and lake thermal refugia on migrating adult Weaver Creek sockeye salmon (Oncorhynchus nerka). Canadian Journal of Fisheries and Aquatic Sciences, in press. Patterson, D. A., J. S. Macdonald, K. M. Skibo, D. P. Barnes, I. Guthrie, and J. Hills. 2007. Reconstructing the summer thermal history for the lower Fraser River, 1942 to 2006, and implications for adult sockeye salmon (Oncorhynchus nerka) spawning migration. Canadian Technical Report of Fisheries and Aquatic Sciences 2724:vii+43p. Pon, L. B., S. G. Hinch, S. J. Cooke, D. A. Patterson, and A. P. Farrell. 2009a. A comparison of the physiological condition of migrant adult sockeye salmon and their attraction into the fishway at Seton River dam, British Columbia under three operational water discharge rates. North American Journal of Fisheries Management, in press. Pon, L. B., S. G. Hinch, S. J. Cooke, D. A. Patterson, and A. P. Farrell. 2009b. Physiological, energetic and behavioural correlates of successful fishway passage of adult sockeye salmon (Oncorhynchus nerka) in the Seton River, British Columbia. Journal of Fish Biology 74:1323-1336. Pon, L. B., S. J Cooke, and S. G. Hinch. 2006. Passage Efficiency and Migration Behaviour of Salmonid Fishes at the Seton Dam Fishway. Final Report for the Bridge Coastal Restoration Program, Project 05.Se.01, 105p. Roscoe, D. W., and S. G. Hinch. 2009. Effectiveness monitoring of fish passage facilities: historical trends, geographic patterns and future directions. Fish and Fisheries, in press. Roscoe, D. W., and S. G. Hinch. 2007. Fishway passage, water diversion and warming temperatures: Factors limiting successful spawning migration of Seton-Anderson watershed sockeye salmon. Final Report for the Bridge Coastal Restoration Program, Project 07.BRG01, Vancouver, BC, 101p.  98  Thorstad, E. B., F. Okland, F. Kroglund, and N. Jepsen. 2003. Upstream migration of Atlantic salmon at a power station on the River Nidelva, Southern Norway. Fisheries Management and Ecology 10:139-146. Williams, J. G. 1998. Fish passage in the Columbia River, USA and its tributaries: problems and solutions. Pages 180-192 in M. Jungwirth, S. Schmutz and S. Weiss, editors. Fish Migration and Fish Bypasses. Fishing News Books, Oxford.  99  CHAPTER 5: Do levels of reproductive hormones and gross somatic energy influence thermoregulatory and migration behaviour of adult sockeye salmon migrating through stratified lakes?3  Introduction Across multiple taxa, reproductive migrations require that individuals travel long distances while coping with variable environmental conditions and preparing for reproduction (Dingle, 1996). For Pacific salmon, such migrations are fuelled entirely by endogenous energy reserves since individuals cease feeding before leaving the ocean en route to freshwater spawning streams. Because Pacific salmon are semelparous, the successful completion of these migrations is paramount to lifetime reproductive success. Although there are a number of environmental factors that can influence the migration biology of fish (e.g. flows, suspended sediment, dissolved oxygen, temperature), water temperature is known to be particularly important. For example, water temperature regulates many aspects of Pacific salmon migrations including rates of travel (Goniea et al., 2006; Crossin et al., 2008; Keefer et al., 2008), physiological condition (Hinch et al., 2006; Crossin et al., 2008) and en route mortality (Gilhousen, 1990; Macdonald et al., 2000; Keefer et al., 2008). Given the importance of temperature, it is not surprising that migrating salmon are known to behaviourally thermoregulate. Chinook salmon (Oncorhynchus tshawytscha) in the Columbia River Basin, USA, can mitigate negative effects of high water temperatures by utilizing thermal refugia in cool water tributaries (Berman and Quinn, 1991; Goniea et al., 2006). In contrast, the Fraser River, the largest salmon-producing river in Canada, is thermally homogenous (Patterson et al., 2007) and migrating salmon make limited use of the few thermal refugia that are available in the lower river (Donaldson et al., 2009).  3  A version of this chapter has been submitted for publication. Roscoe, D.W., S.G. Hinch, S.J. Cooke, and D.A. Patterson. Behaviour and thermal experience of adult sockeye salmon migrating through stratified lakes near spawning grounds: the roles of reproductive and energetic states.  100  Unlike the river environment, the nursery lakes of sockeye salmon (Oncorhynchus nerka) – large lakes near spawning grounds where juveniles rear – are thermally stratified during the spawning migration, providing a wide range of temperatures to migrants. Because their life history generally involves migration through thermally stratified lakes and temperature has such profound effects on fish (Brett, 1971), sockeye salmon are good models for the study of the effects of behavioural thermoregulation during fish migrations. Several studies have shown that sockeye volitionally or obligatorily utilize cool water in the hypolimnion of lakes during summer migrations and likely do so to enhance their survival. For instance, Hyatt et al. (2003) found that sockeye salmon in the Okanagan River ceased migration if river temperature exceeded 21˚C, likely a critical thermal limit for some sockeye populations (Farrell et al., 2008) and moved downstream to a large lake where cooler water was available. Sockeye salmon return to Lake Washington, USA, in the early summer and reside there for several months, presumably to avoid high water temperatures in spawning streams in midsummer (Hodgson and Quinn, 2002). While residing in Lake Washington, sockeye spend the majority of their time in the hypolimnion at 9-11˚C, rarely occupying warmer or cooler areas (Newell and Quinn, 2005). Adult migrating Weaver Creek sockeye (Fraser River, BC) which entered the Fraser River during peak summer temperatures and volitionally occupied the hypolimnion of a lake upstream of spawning grounds had much higher survival than those that held in the river prior to spawning (Mathes et al., in press). However, previous research has simply documented behavioural thermoregulation. No previous studies have examined how physiological factors may affect thermoregulatory behaviour in wild salmon. Pacific salmon have been used as models to examine the physiological and energetic mechanisms underlying and controlling fish migrations (Hinch et al., 2006). Migratory behaviour is strongly influenced by reproductive physiology as high levels of reproductive hormones such as testosterone and estradiol are related to earlier river entry and faster migration rates (Sato et al., 1997; Crossin et al., 2007; Cooke et al., 2008). Energetic status also appears to be closely linked with migratory behaviour, since individuals with higher energy levels have slower rates of travel and greater survivorship  101  during up-river migration (Young et al., 2006; Hanson et al., 2008). Because energetics and reproductive development are both greatly affected by water temperature, these factors might also be expected to be related to thermoregulatory behaviour. For instance, metabolic rate increases with temperature (Brett, 1971; Lee et al., 2003) and therefore fish experiencing higher temperature will more quickly deplete their finite energy reserves. In general, the rate of reproductive development is also positively related to water temperature, but very warm temperatures can also lead to over-ripening or damage of gametes (Flett et al., 1996; Pankhurst et al., 1996). For these reasons, Newell and Quinn (2005) proposed that the narrow range of temperatures occupied by sockeye salmon in Lake Washington (discussed above) represented a tradeoff that balanced reproductive maturation and metabolic energy expenditure. However, the hypothesis that thermoregulatory or other in-lake behaviour is related to reproductive hormone levels and energy reserves has not yet been tested in migrating adult salmon. The present study utilizes non-lethal biopsy, acoustic telemetry and temperature loggers to document the behaviour and thermal experience of sockeye in lakes near spawning areas. We non-lethally sampled levels of somatic energy and circulating hormones to investigate the hypothesis that behaviour and temperature preference are related to levels of energy and reproductive maturation. Because sockeye have a fixed amount of time and energy to reach spawning areas and warmer temperatures result in relatively higher metabolic expenditures, we predicted that individuals with low levels of energy would migrate faster and more directly and select cooler temperatures. We also predicted that individuals which were more reproductively advanced, as indicated by circulating levels of hormones, would migrate faster and more directly, and seek out lower temperatures than less mature individuals.  Methods Study site The study was carried out in the Seton-Anderson watershed in Southwestern interior of British Columbia on Gates Creek sockeye salmon (Figure 5.1). As adults, this salmon stock migrates up the Fraser River 320 km from the Pacific Ocean before  102  reaching the mouth of the Seton River, near Lillooet, BC. Migrants then travel 5 km up the Seton River where they must pass the Seton dam via a vertical-slot fishway. After passing the dam, migrants travel through Seton Lake (22 km), Portage Creek (3 km) and Anderson Lake (21.5 km), which serves as the nursery lake for Gates Creek sockeye. Spawning areas are immediately upstream of Anderson Lake in Gates Creek and in an artificial spawning channel ~800 m upstream of the creek mouth in the town of D’Arcy, BC. Seton Lake is a large lake along the migratory route, often known as a ‘corridor’ lake. Although the lake is natural, the outflow was impounded in 1956 about 760 m downstream of the lake, causing the water level to rise approximately 2 m. Only sixteen percent of Seton Lake’s inflow comes from the Seton-Anderson basin, whereas 78% comes from an inter-basin diversion from the adjacent Bridge River watershed. The remaining 4% of the lake’s inflow comes from Cayoosh Creek, a tributary that naturally flows into the lower Seton River but that is diverted in part into Seton Lake ~300 m from the outflow (BCRP, 2000).  Fish handling, tagging and biopsy Fish were captured by dip-net from the top pool of the Seton dam fishway on August 16-24, 2007. To achieve various objectives of a parallel study concerning the impacts of hydro-facilities on spawning migration, we transported and released fish at different locations in the watershed. After capture by dip net, fish were transferred to a truck-mounted aluminium transport tank (1 m x 1 m x 1.5 m) filled with river water and continuously aerated with a 30 cm long air diffuser. Because transportation of salmonids can be stressful (Chandroo et al., 2005), after transportation to the release site fish were placed in a mesh net-pen for 5 hours to recover before they were tagged, biopsied and released. Fish that were transported and held in net-pens before tagging were released at one of three locations (sites B, C, and D, Figure 5.2): 1) Fraser River, 1.2 km downstream of the Seton River at the powerhouse outflow (32 fish), 2) lower Seton River at Cayoosh Creek (27 fish), or 3) Seton Lake near the outflow (8 fish). In order to evaluate the effects of transportation and net-pen holding, an additional 20 sockeye were caught in the fishway, and transferred immediately (< 10 seconds) to the sampling trough for biopsy sampling and tagging. After tagging these fish were immediately released into the Seton  103  River on the upstream side of the dam and fishway (site A, Figure 5.2). We compared fish from different release sites and between net-pen held and immediately released fish to assess whether these different treatments affected subsequent migration behaviour. Tagging and biopsy sampling followed procedures described in Cooke et al. (2005). Fish were placed in a foam-lined v-shaped trough with a continuous supply of fresh river water directed towards the fish’s head and gills. No anesthetic was used and one researcher restrained the fish in the trough during the procedure. A 1.5 mL blood sample was taken from the caudal vasculature (Houston, 1990) using a heparinized Vacutainer syringe (1.5 inches, 21 gauge, lithium heparin). Blood samples were centrifuged for 6 minutes to separate plasma from red blood cells and plasma was stored in liquid nitrogen, then transferred to a -80˚C freezer for storage until analysis. Fork length was measured to the nearest 5 mm. A small tissue sample was removed from the adipose fin using a hole punch and stored in ethanol for subsequent DNA analysis to confirm population of origin (Beacham et al., 2004). Somatic lipid concentration was measured using a hand-held microwave energy meter (Fatmeter model 692, Distell Inc., West Lothian, Scotland, UK) and converted to estimates of gross somatic energy (GSE) using relationships described by Crossin and Hinch (2005). Fish were marked with an external tag (FT-4 Cinch up, Floy Tag Inc., Seattle, WA) attached through the dorsal musculature immediately anterior to the dorsal fin using a hollow needle. The external tag permitted visual identification of study sockeye on spawning grounds or if they were caught by in-lake subsistence fisheries. An acoustic telemetry transmitter (V16-1HR64K coded transmitters, Vemco Inc., Shad Bay, NS) was inserted into the stomach using a plastic tag applicator (Ramstad and Woody, 2003).  Laboratory analysis 17ß-estradiol and testosterone concentrations were measured in duplicate using enzyme-linked immunosorbent assay (ELISA) kits (Neogen Co., Lexington, KY, USA). Plasma testosterone and 17ß-estradiol were ether-extracted according to kit directions prior to completing the assays. Measurements were repeated if the coefficient of variation between replicates was greater than 10%. To determine the sex of individual  104  fish 17ß-estradiol was plotted versus testosterone resulting in two distinct clusters of points, which corresponded with males and females, a method validated previously on destructively sampled fish (D. Patterson, pers. comm.). Estradiol assays were optimized to examine the entire range of values for males and females, not to quantify absolute levels in females. As such, estradiol values are a relative index but do not necessarily represent the absolute hormone titre available. One assumption of our analysis is that the levels of hormones and GSE measured at the time of capture are representative of the fish’s physiological and energetic state during subsequent migration through the lakes. All fish released downstream of the dam that we had temperature data for passed the dam and entered the lake relatively quickly (most in less than 3 days with a maximum of 6 days). All study fish had similar treatment and our handling did not cause undue stress (see Chapter 3). Therefore, the assumption that hormones and energy levels measured at capture are representative of fish’s condition in the lakes is likely sound.  Temperature logging Archival temperature loggers (iButton Thermochrons, DS1921Z, Maxim Integrated Products, Inc., Sunnyvale, CA) were waterproofed and attached to all telemetry transmitters before transmitter insertion using a non-toxic adhesive. Loggers were the same diameter as transmitters and when attached increased the transmitter length by ~8 mm. Loggers were programmed to record temperature once every hour (manufacturer specified accuracy =1˚C, resolution = 0.1˚C). Because temperature loggers do not transmit data, temperature profiles were only obtained from fish recovered on spawning grounds. A series of temperature loggers were suspended vertically in the water column to measure temperature at various depths at 3 locations in Seton Lake and 2 locations in Anderson Lake. These loggers were attached to the lines from moorings at telemetry receiver stations at various depths between 5 m and 65 m. Temperatures from individual fish were also used in conjunction with loggers at known depths in the water column to estimate approximate depths of fish and whether or not they made diurnal vertical migrations, as others have described for sockeye salmon (Mathes et al., in press).  105  Acoustic telemetry and lake behaviours A fixed array of telemetry receivers (VR2, Vemco Inc., Shad Bay, NS) was used to monitor fish movements (Figure 5.1). The present study focuses on data from 8 receivers in Seton and Anderson lakes although there were an additional 9 receivers deployed in the Seton River and in the fishway to monitor fishway passage for a separate study (see Chapter 3). In both Seton and Anderson lakes, there was one receiver at the inflow, one at the mouth and two along the migration route deployed at locations intended to maximize detection efficiency and coverage of the lake habitat. Receivers were either suspended in the water column using sandbags, rope and subsurface buoys (6 receivers) or attached to a fixed structure (e.g. log or dock; 2 receivers). Data from telemetry receivers were downloaded and detection efficiency for each receiver was calculated using the method of Jolly (1982) as described by Welch (2007). Since the receiver at the mouth of Seton Lake (Receiver 1, Figure 5.1) was slightly downstream of the Seton Lake release site, fish released at this site were not included for detection efficiency for that receiver. As calculating a detection efficiency requires an upstream receiver, efficiency could not be calculated for the receiver at the inflow of Anderson Lake. We calculated travel speeds through Seton (receiver 1-4) and Anderson (receiver 5-8) lakes, and for the total lake migration (receiver 1-8). Travel speeds were calculated by the distance of a segment divided by the difference in time between the first detections at the first and last receivers of a given segment. When analyzing the data we observed that some fish would migrate directly through each of the lakes and move upstream to spawning areas without delay, whereas other individuals took a less direct path or held in lakes for some time. To describe these differences we classified fish in terms of two additional lake behaviours, circling and holding, in each of the lakes. Circling was defined as any movement of one receiver station or more in a ‘downstream’ direction. Holding was defined as residing in the lake for longer than 24 hours after having reached the inflow of the lake. Although some fish died in the lakes before reaching the inflow of Anderson Lake, we included all fish that were present in a given lake for analysis of  106  travel speeds and behaviours, regardless of fate. For example, a fish that was last detected in Anderson Lake but did not reach the inflow, was still be included for analysis of travel speed and behaviour in Seton Lake.  Statistical analysis One-way analysis of variance (ANOVA) was used to compare travel speeds between sexes, release sites and between net-pen held and immediately released fish. The frequency of circling and holding behaviours was compared between sexes, release sites and net-pen holding groups using chi-square analysis, or Fisher’s Exact test if expected cell sizes were less than five. We recovered temperature loggers from 24 sockeye salmon. For each fish we calculated the mean temperature (Tmean), the 5th percentile (T5), and the 95th percentile (T95) while in Seton Lake, Anderson Lake, and for the total lake migration through Seton Lake, Portage Creek and Anderson Lake. We chose these particular percentile temperature calculations to describe the coolest and warmest temperatures that fish experienced for appreciable amount of time and which we believe are more likely to affect physiology rather than short term exposure to minimum or maximum temperatures. Pearson’s correlations were used to assess whether temperature experience, GSE or hormones were related to Julian date. Levels of hormones and energy were compared between fish that circled or held and those that did not using one-way ANOVA. We conducted a series of linear regressions to assess the relationship between travel speed and measures of temperature exposure for the whole lake migration (the response variable), and energy and reproductive hormone levels (the predictor variables). Because males and females were significantly different in terms of GSE and testosterone, sex was included as a class variable in the regression. Because the variable estradiol was femalespecific, its relationship with travel speed and temperature exposure was assessed separately with simple linear regressions. Travel speed in the lake was log10 transformed in order to meet model assumptions whereas all the other variables did not require transformation. All analyses were carried out in SAS v.9.1.3 (SAS Inc., Cary, N.C.).  107  Statistical significance was assessed at the 0.05 level. For analyses of the three temperature variables, we were not able to conduct multivariate analyses because of small sample sizes. Instead, Bonferroni correction for the three regressions predicting temperature variables resulted in a significance level of 0.017. However, because Bonferroni correction is highly conservative, making the chance of a type II error likely, we present probabilities for all analyses and allow the reader to draw their own conclusions regarding what significance level, Bonferroni corrected or not, is most biologically meaningful, as recommended by Cabin and Mitchell (2000).  Results We released 87 sockeye salmon at 4 different sites. Twenty-one fish never moved upstream of the fishway and therefore provided no information on in-lake behaviour. Detection efficiencies for all telemetry receivers in the array were 100% indicating an excellent ability to monitor behaviour and fate of fish in the lakes. First, we needed to evaluate any potential differences in behaviour among fish released at different locales and between fish held in net-pens and those that were not. Mean travel speed from the mouth of Seton Lake to the inflow of Anderson Lake was not different between net-pen held and immediately released fish (P=0.17) or between fish released upstream (sites A and B pooled) and downstream of the dam (sites C and D pooled; P=0.11). The frequency of circling and holding behaviours was independent of release site in Seton Lake (P=0.92 and P=0.32). In Anderson Lake, circling was independent of release site (P=0.079) but a greater percentage of fish released upstream of the dam displayed holding behaviour (88%) compared to fish released downstream (52%; P=0.004). More holding in the fish released upstream versus downstream of the dam may have been related to earlier tagging of the upstream released fish, since fish released upstream of the dam were caught and released primarily during the earlier portion of our tagging period. Because few fish were tagged and released downstream of the dam during the early part of our tagging period we were not able to separate the effects of timing versus release site on holding behaviour in Anderson Lake. Because behaviour of fish from all release sites and net-pen holding treatments was generally not  108  different (except for a greater frequency of holding in the fish tagged earliest in the season), we pooled these groups for subsequent analyses. Travel speed (mean ± SE) was 38.4 ± 2.4 km•day-1 in Seton Lake (n=62) and 17.0 ± 2.2 km•day-1 in Anderson Lake (n=53). Travel speed from the first detection at the mouth of Seton Lake to arrival at the inflow of Anderson Lake, including migration through Portage Creek and holding or circling before reaching the inflow of Anderson Lake, was 13.6 ± 1.1 km•day-1 (n=51). Travel speed did not differ by sex (P=0.22). Circling behaviour was displayed by 19 of 65 fish (29%) in Seton Lake and 22 of 58 of fish (38%) in Anderson Lake. Holding behaviour was displayed by 15 of 64 fish (23%) in Seton Lake and 37 of 53 fish (70%) in Anderson Lake. Neither circling nor holding were associated with sex in Seton Lake (P=0.7 and P=0.13, respectively) or Anderson Lake (P=0.31 and P=0.93). Temperature loggers suspended in the water column confirmed that Seton and Anderson lakes were both thermally stratified during the study period (Figure 5.3). In Anderson Lake, the thermocline was situated between approximately 10 m and 30 m depth and the hypolimnion started at approximately 30 m. In Seton Lake, the thermocline appeared to be deeper, between 25 m and 45 m, although the epilimnion, thermocline and hypolimnion were less distinct compared to Anderson Lake. Temperature loggers were recovered on spawning grounds from 24 fish. Temperature exposure in the lakes varied among individuals (Figure 5.4) and between the two lakes (Table 5.1). T95 ranged from 15-19˚C. The warmest temperatures were encountered mostly in Portage Creek although some fish encountered temperatures as high as 18˚C in the epilimnion of Anderson Lake. The coolest temperatures experienced appeared to be much more variable, as indicated by the large range of T5 (6-14˚C) among fish. Temperatures below 10˚C were typically encountered in Anderson Lake, whereas temperature experience was less variable in Seton Lake (11-16˚C; Table 5.1). Three examples of the varying thermal history among individual fish during migration through the lakes are shown in Figure 5.5. None of the temperatures variables (T5, Tmean, and T95)  109  differed between males and females (all P>0.5). All fish were released within a 10-day period and temperature variables were not related to Julian date (all P>0.05), indicating that temperature experience can be attributed to individual fish behaviour and was not simply related to the date of release. Some fish displayed diurnal vertical migrations, occupying cooler water in the hypolimnion during the day and moving into the epilimnion and near the surface during the night. An example of diurnal vertical migration is shown for one fish (Figure 5.5A). However, many fish that did migrate to the surface at night did not do so every night, and some fish did not display this behaviour at all (e.g. Figure 5.5C). This behaviour was observed only in Anderson Lake and not in Seton Lake. GSE (mean ±SE) was 5.8 MJ•kg-1 ± 0.09 for males (n=26) and 6.5 MJ•kg-1 ± 0.07 for females (n=36). Testosterone concentration was 6.5 ng•mL-1 ± 1.1 for males (n=26) and 10.7 ng•mL-1 ± 1.5 for females (n=31). Estradiol concentration was 1.6 ng•mL-1 ± 0.1 for females and less than 0.12 ng•mL-1 for all males. We used a series of linear regressions to assess relationships between travel speed and measures of temperatures experience, and GSE and testosterone while accounting for sex differences (Table 5.2). Testosterone was not a significant variable in the model predicting travel speed or any of the models predicting temperature variables. Therefore, we removed testosterone from all the regressions and used only GSE and sex as predictor variables. In the model with travel speed as the response variable (P=0.02, R2=0.19), GSE was significant (P=0.0058) but the slope adjustment for females was not (P=0.74) suggesting that GSE was positively related to travel speed for males but not females. Of the three regressions using the three temperature experience measures as a response variable, only the model predicting T95 was significant (P=0.049, R2=0.33), although not after Bonferroni correction. In the model, GSE was a significant predictor for females but not for males (Table 5.2). Estradiol was not a significant predictor of travel speed (P=0.7) but was a significant predictor of T5 (P=0.01, R2=0.73) and Tmean (P=0.004,  110  R2=0.83; Figure 5.6). Neither estradiol nor GSE were correlated with Julian date (both P>0.3).  Discussion This study is the first to link individual variation in thermoregulatory behaviour to differences in physiological condition of Pacific salmon during spawning migration. We found evidence to support the hypothesis that thermal behaviour is related to energy levels and reproductive status of adult sockeye salmon. The warmest temperatures experienced (i.e. T95) were positively related to energy levels, which was consistent with our prediction that fish with lower energy would select cooler temperatures. However, this relationship was only significant for females and not for males. Since females allocate more energy to gonad development than males, there may be stronger selection for energy-saving tactics in females compared to males (Hinch et al., 2006). Indeed, studies of Fraser River sockeye reported that females are more energetically efficient swimmers (Hinch and Rand, 1998; Standen et al., 2002) and have more streamlined body shapes, which reduce energetic costs of swimming (Crossin et al., 2004). The present study provides further evidence of energy-saving patterns in migrating adult female sockeye. Females that had low energy did not select temperatures as high as those with relatively greater energy reserves, and would have thus reduced their metabolic energy expenditure. Estradiol was positively related to the lowest temperatures encountered by female sockeye, meaning that female fish that had lower levels of estradiol selected the coolest temperatures. Estradiol is a hormone that stimulates the synthesis of vitellogenin (So et al., 1985), which is released into circulation and then taken up by oocytes in the ovary (Ng and Idler, 1983). In migrating sockeye, estradiol levels increase during coastal and early riverine migration, but decline quickly prior to reaching spawning grounds (Leonard et al., 2002) when vitellogenesis ends and final maturation of the oocytes begins (Truscott et al., 1986). Because fish in our study were less than 60 km from spawning areas and likely within 1-2 weeks of spawning, our interpretation is that female fish that had lower levels of estradiol were more reproductively advanced compared to  111  fish with higher levels of estradiol. As predicted, the more reproductively advanced fish had cooler temperature exposure with many individuals spending time at very cool temperatures (~5-7˚C) by swimming into deep layers of the lake. Newell and Quinn (2005) suggested that the temperatures between 9-11˚C where sockeye salmon in Lake Washington, USA spent the majority of their time were optimal for sexual maturation. Similarly, McCullough et al. (2001) concluded, based on their literature review, that temperatures of 10-12.5˚C are optimal for maturation of salmonids. The much cooler temperatures utilized by some fish in our study may have been selected to slow rate of maturation, since cool temperatures can slow the rate of reproductive development and over-ripening can lead to reduced fitness in salmon (Flett et al., 1996). Previous studies have shown that temperature preference of Atlantic stingrays (Dasyutis sabina) and thermoregulatory behaviour of bluefin tuna (Thunnus thynnus) may vary depending on stage of reproductive development (Wallman and Bennet, 2006; Teo et al., 2007). However, cold temperatures could confer several other benefits to adult sockeye salmon including slowing the rate of disease development (Wagner et al., 2006) and reducing energetic costs of metabolism (Lee et al., 2003; Farrell et al., 2008). Although we observed interesting patterns between temperature experience and estradiol, testosterone was not related to either in-lake behaviour or temperature experience. In both male and female sockeye salmon, levels of circulating testosterone increase over the course of migration (Hinch et al., 2006) and then drop sharply after spawning (Truscott et al., 1986). Originally, we predicted that fish that were more reproductively advanced, those with higher levels of testosterone, would select cooler water temperatures and travel faster and more directly than less mature fish. Crossin et al. (2007) found that higher testosterone was associated with earlier river-entry timing and faster travel speed in adult sockeye salmon. In addition, based on the relationship shown here between estradiol and temperature exposure, and known strong effects of temperature on fitness, it seems likely that reproductive maturity is an important driver of temperature preference. It may be that testosterone is a useful predictor of in-lake and thermoregulatory behaviour, but that methodological issues limited our ability to detect these relationships. For instance, a low sample size likely resulted in low statistical  112  power. In total we recovered 24 of the 88 temperature loggers deployed, but since 3 females did not have blood samples, we had both temperature and physiological data for only 14 males and 7 females. Other studies using archival temperature loggers that must be recovered from fish carcasses have reported even lower recovery rates (38 of 257, Newell and Quinn, 2005; 48 of 1038, Donaldson et al., 2009). Studies using temperature-sensing telemetry (e.g. Bermann and Quinn, 1991) can avoid the problem of recovering loggers but the high cost of these telemetry transmitters may also limit sample sizes and data are only collected when the transmitter is in the range of a receiver (Cooke et al., 2004). In general, patterns of movement (i.e. holding and circling) and rates of travel of sockeye in Seton and Anderson lakes were not related to levels of energy or the reproductive hormones measured. The only exception was that GSE was positively related to travel speed of males. This finding was contrary to our prediction that fish with lower energy reserves would travel faster and more directly in order to reach spawning areas and reproduce before exhausting their energy reserves. A possible explanation for the positive relationship between GSE and travel speed could be that if energy levels are too low in sockeye, migration is impaired and fish travel more slowly. However, none of the fish had energy levels that were critically low, such that impaired or slowed migration would be expected. Crossin et al. (2004) estimated that the minimum energy density required to sustain life was 4 MJ•kg-1 whereas all but one of the individuals had GSE greater than 5 MJ•kg-1. Alternatively, perhaps fish that had low energy swam at speeds that resulted in lower energy cost per unit distance and slower overall travel speeds. The shape of the energy cost versus swimming speed relationship is parabolic, with optimal speed of approximately 2 km•hr-1 (Brett, 1995). However, average travel speed in the lakes (13.6 km•day-1, or 0.6 km•hr-1) was well below the optimum, suggesting that the relationship between travel speed and GSE is not likely explained by swimming efficiency. Because our travel speeds are minimum estimates averaged over relatively large distances, and fish likely do not swim in a straight line, faster travel speeds do not necessarily suggest faster swimming speeds. Consequently, we do not know whether fish with lower energy actually swam at slower or more energetically efficient speeds.  113  Although the spawning migrations of sockeye salmon have been studied extensively (Burgner, 1991; Hinch et al., 2006), most research has focused on the river or near-shore coastal environment and only a few previous studies have examined in-lake behaviour. We found that on average sockeye travelled slower in the lakes (13.6 ± 1.1 km•day-1) than has been reported for sockeye migrating up-river (17-40 km•day-1; English et al., 2005) or in the ocean (30-55 km•day-1, Neave, 1964; 20-33 km•day-1, Crossin et al., 2007). Sockeye salmon migrating through Lake Clark, Alaska travelled even slower than fish in our study, averaging 4.7 km•day-1 for tributary spawning individuals and 1.6 km•day-1 for lake spawners (Young and Woody, 2007). Interestingly, average travel speeds through Seton Lake (38.4 ± 2.4 km•day-1) were as fast or faster than in the river or ocean, although this rate does not include time spent milling at inlet of the lake before moving upstream into Portage Creek. These comparisons highlight the importance of considering the resolution of fixed telemetry arrays and the scale over which minimum travel speeds are calculated. For instance, Young and Woody (2007) calculated travel speeds from the time of release to when salmon reached spawning areas, thus, including all time spent milling and potentially re-orientating after release and recovery. This difference in methods may explain the much slower travel speeds observed in that study compared to ours. We observed many fish holding near lake inlets or circling, providing further evidence that lake migration is not necessarily linear and direct, which was reported previously in Lake Clark, Alaska (Young and Woody, 2007). Interestingly, behaviour differed substantially between a corridor and nursery lake that were a short distance apart and both near spawning areas. Although Seton and Anderson lakes are very similar in size and temperature profile, sockeye travelled much faster through (38.4 ± 2.4 km•day-1 vs. 17.0 ± 2.2 km•day-1) and were less likely to circle and hold in Seton Lake compared to Anderson Lake. Therefore, it may be that migration through corridor lakes is rapid and direct whereas migration in nursery lakes is less direct. We found that more fish released upstream of the dam displayed holding behaviour in Anderson Lake compared to those released downstream of the dam. However, behaviour was otherwise not different  114  between fish from different released sites, and we suspect that greater propensity to hold in Anderson Lake was related to the earlier timing of fish released upstream of the dam, and not because of their release location. Thus, it may be that earliest fish of the spawning run may hold longer in the lake, perhaps to complete reproductive maturation (Hinch et al., 2006). Temperature exposure also differed between Seton and Anderson lakes, with generally warmer and less variable temperatures experienced by fish in Seton Lake compared to Anderson Lake. Very high temperatures that are known to be stressful to sockeye salmon (>18˚C; Crossin et al., 2008) were rarely encountered by fish in our study, regardless of energetic or reproductive status. Fish apparently avoided the warm epilimnion of the lake (approximately 16-18˚C) and spent little time in Portage Creek (~3 km migration distance), where temperatures were as high as 20˚C and cooler temperatures in deeper water are not available. Avoidance of high temperatures by Pacific salmon has been reported by others (Newell and Quinn, 2005; Mathes et al., in press) and is not surprising, given the high mortality associated with exposure to very high temperatures (Crossin et al., 2008; Farrell et al., 2008; Keefer et al., 2008). In Anderson Lake, the lowest temperatures experienced by fish were much more variable than the highest temperatures. For instance, some fish spent time at temperatures near 6˚C, whereas others never experienced temperatures cooler than 10˚C. Since water temperatures of 6˚C corresponded to depths of 30-50 m, some sockeye were likely actively seeking out these cool temperatures by descending into the hypolimnion, whereas others continued to migrate closer to the surface. Mathes et al. (in press) found that Weaver Creek sockeye holding in Harrison Lake prior to spawning, spent the majority of their time (> 80%) in the hypolimnion at 6.5˚C. Sockeye in Harrison Lake had more pronounced and consistent diel vertical migrations, travelling to the surface every night, whereas in our study only some sockeye displayed this behaviour, and not necessarily every day. Differences between the time spent in the hypolimnion and consistency of vertical migrations by sockeye in our study versus those in Mathes et al. (in press) could be related to the fact that Weaver sockeye were holding in the lake before moving to downstream spawning areas, whereas Gates sockeye were actively migrating.  115  Differences in behaviour could also be related to their previous migratory experience, since Weaver sockeye experienced temperatures near their upper critical thermal limit in Fraser River during the year of study (2004) and may have used the lake as a refuge to recover from thermally induced stress (Mathes et al., in press). In contrast, migratory conditions for Gates sockeye in 2007 were favourable as temperatures were near longterm averages. This study provides new information on the patterns of movement and thermoregulatory behaviour of sockeye during migration through corridor and nursery lakes. As predicted, these behaviours seem to be linked to changes in energetics and reproductive endocrinology that occur during the final phase of freshwater migration. One consequence of using archival temperature loggers is that data is typically only recovered from successful migrants and not from fish that die before reaching spawning grounds. Interestingly, there was no single thermal behaviour pattern that was consistent with survival to spawning grounds, as successful migrants displayed a range of temperature preferences. However, we are unable to assess the effect of variable temperature exposure on fate, and whether migrants that die before reaching spawning grounds may behave differently. Understanding the consequences of in-lake behaviour and thermoregulation are important future research priorities, since thermal refugia in lakes may be crucial to survival during warm temperature years (Mathes et al., in press), and such information will provide insight into how salmon populations may cope with increasing river temperatures associated with global climate change (Ferrari et al., 2007).  116  Table 5.1. Range of values of mean, 5th percentile (T5) and 95th percentile (T95) temperatures experienced by 24 sockeye salmon during migration through lakes to spawning areas. Values are shown for Seton Lake, Anderson Lake, and the total lake migration, which includes migration through both lakes and Portage Creek. Values of the three temperature variables for the total migration were used in regressions using energy and reproductive hormones to predict temperature experience (see Table 5.2). Range (min – max; ˚C) Temperature variable  Seton Lake  Anderson Lake  Total  Mean  12.9 – 15.0  9.6 – 14.5  12.3 – 15.9  T5  11.4 – 13.9  5.9 – 13.6  6.1 – 13.8  T95  13.9 – 16.4  12.9 – 17.4  15.3 – 18.8  117  Table 5.2. Parameter estimates (slope or intercept) and probabilities (in parentheses) from regressions predicting travel speed or measures of temperature experience using GSE and sex (males and females) for sockeye salmon migrating through Seton Lake, Portage Creek and Anderson Lake. Sex was included by creating a dummy variable for females; thus, the female values for the intercept (Int.), and slope of GSE are adjustors added to the corresponding male values. The effect of the female-specific hormone estradiol on travel speed and measures of temperature was modelled separately in simple linear regressions. Degrees of freedom (df) from the model and error are shown for each regression. Probabilities significant at 0.05 are shown in bold text. Males (M) and females (F) Response variable  Model  Travel speed (0.02)  Females  Int. (M)  Int. (F)  GSE (M)  GSE (F)  Estradiol  -0.32  0.4  0.25  -0.11  0.03  (0.5)  (0.7)  (0.009)  (0.5)  (0.7)  df=3,44 Mean T (0.8)  df=1,19 13.5  -4.3  -0.02  0.64  2.6  (<0.0001)  (0.4)  (1.0)  (0.4)  (0.004)  df=3,19 T5 (0.9)  df=1,5 12.2  -7.7  -0.36  1.2  5.5  (0.04)  (0.5)  (0.7)  (0.5)  (0.01)  df=3,19 T95 (0.049)  df=1,5 16.4  -10.8  0.04  1.69  1.3  (<0.0001)  (0.03)  (0.9)  (0.03)  (0.3)  df=3,19  df=1,5  118  Figure 5.1. Map of Seton-Anderson watershed showing locations of telemetry receivers (numbers), spawning channel and some hydroelectric facilities.  119  Figure 5.2. Map of the lower Seton River and surrounding area showing location of 4 sites (letters) where telemetered sockeye salmon were released after tagging.  120  Figure 5.3. Water temperature at various depths in Seton and Anderson lakes in 2007. Temperature was measured hourly at numbered receiver stations (see Figure 5.1) and values are means from August 16 – September 5.  121  Figure 5.4. Box plots of temperature experience of 24 fish while migrating through Seton Lake, Portage Creek and Anderson Lake. For each individual, the mean, 25th and 75th percentile (boxes), 10th and 90th percentiles (whiskers), and 5th and 95th percentiles (black circles) are shown.  122  Figure 5.5. Thermal history of 3 exemplar sockeye salmon during migration in the Seton-Anderson watershed in British Columbia, Canada. Temperature experience varied among individuals, particularly in Anderson Lake, with some fish displaying diurnal vertical migration (A), or experiencing relatively warm (B) or cool (C) temperatures. Temperatures were measured hourly by archival loggers attached to telemetry transmitter and inserted into stomach of each fish. Arrows show approximate time that fish entered different sections of the migration route.  123  Figure 5.6. Plots of significant relationships between in-lake travel speed and temperature experience, and gross somatic energy and hormones of adult sockeye salmon migrating through lakes near spawning areas.  124  References BCRP. 2000. Bridge-coastal fish and wildlife restoration program, Seton River Watershed strategic plan. Volume 2, Chapter 11. Burnaby, BC, 28p. Accessed on May 18, 2009: http://www.bchydro.com/bcrp/projects/docs/07.BRG.01.pdf Beacham, T. D., M. Lapointe, J. R. Candy, K. M. Miller, and R. E. Withler. 2004. DNA in action: Rapid application of DNA variation to sockeye salmon fisheries management. Conservation Genetics 5:411-416. Berman, C. H., and T. P. Quinn. 1991. Behavioural thermoregulation and homing by spring Chinook salmon, Oncorhynchus tshawytscha (Walbaum), in the Yakima River. Journal of Fish Biology 39:301-312. Brett, J. R. 1971. Energetic responses of salmon to temperature: A study of some thermal relations in the physiology and freshwater ecology of sockeye salmon (Oncorhynchus nerka). American Zoologist 11:99-113. Brett, R. 1995. Energetics. In: Physiological ecology of Pacific salmon. Edited by C. Groot, L. Margolis and W.C. Clarke. The University of British Columbia Press, Vancouver. pp. 1-68. Burgner, R. L. 1991. Life history of sockeye salmon (Oncorhynchus nerka). Pages 1-117 in C. Groot and L. Margolis, editors. Pacific Salmon Life Histories. University of Briish Columbia Press, Vancouver, BC. Cabin, R. J. and R. J. Mitchell. 2000. To Bonferroni or not to Bonferroni: when and how are the questions. Bulletin of the Ecological Society of America 81: 246-248. Chandroo, K. P., S. J. Cooke, R. S. McKinley, and R. D. Moccia. 2005. Use of electromyogram telemetry to assess the behavioural and energetic responses of rainbow trout, Oncorhynchus mykiss (Walbaum) to transportation stress. Aquaculture Research 36:1226-1238. Cooke, S. J., G. T. Crossin, D. A. Patterson, K. K. English, S. G. Hinch, J. L. Young, R. F. Alexander, M. C. Healey, G. Van Der Kraak, and A. P. Farrell. 2005. Coupling non-invasive physiological assessments with telemetry to understand inter-individual variation in behaviour and survivorship of sockeye salmon: Development and validation of a technique. Journal of Fish Biology 67:1342-1358. Cooke, S. J., S. G. Hinch, G. T. Crossin, D. A. Patterson, K. K. English, M. C. Healey, J. S. Macdonald, J. M. Shrimpton, J. L. Young, A. Lister, G. Van Der Kraak, and A. P. Farrell. 2008. Physiological correlates of coastal arrival and river entry timing in late summer Fraser River sockeye salmon (Oncorhynchus nerka). Behavioral Ecology 19:747-758.  125  Cooke, S. J., S. G. Hinch, M. Wikelski, R. D. Andrews, L. J. Kuchel, T. G. Wolcott, and P. J. Butler. 2004. Biotelemetry: A mechanistic approach to ecology. Trends in Ecology & Evolution 19:334-343. Crossin, G. T., S. G. Hinch, S. J. Cooke, D. W. Welch, D. A. Patterson, S. R. M. Jones, A. G. Lotto, R. A. Leggatt, M. T. Mathes, J. M. Shrimpton, G. Van der Kraak, and A. P. Farrell. 2008. Exposure to high temperature influences the behaviour, physiology, and survival of sockeye salmon during spawning migration. Canadian Journal of Zoology 86:127-140. Crossin, G. T., S. G. Hinch, S. J. Cooke, D. W. Welch, S. D. Batten, D. A. Patterson, G. Van Der Kraak, J. M. Shrimpton, and A. P. Farrell. 2007. Behaviour and physiology of sockeye salmon homing through coastal waters to a natal river. Marine Biology 152:905-918. Crossin, G. T., S. G. Hinch, A. P. Farrell, D. A. Higgs, A. G. Lotto, J. D. Oakes, and M. C. Healey. 2004. Energetics and morphology of sockeye salmon: Effects of upriver migratory distance and elevation. Journal of Fish Biology 65:788-810. Crossin, G. T., and S. G. Hinch. 2005. A nonlethal, rapid method for assessing the somatic energy content of migrating adult Pacific salmon. Transactions of the American Fisheries Society 134:184-191. Dingle, H. 1996. Migration: The biology of life on the move. Oxford University Press, Oxford. Donaldson, M. R., S. J. Cooke, D. A. Patterson, S. G. Hinch, D. Robichaud, K. C. Hanson, I. Olsson, G. T. Crossin, K. K. English and A. P. Farrell. 2009. Limited behavioural thermoregulation by adult upriver-migrating sockeye salmon (Oncorhynchus nerka) in the Lower Fraser River, British Columbia. Canadian Journal of Zoology 87:480-490. English, K. K., W. R. Koski, C. Sliwinski, A. Blakley, A. Cass, and J. C. Woodey. 2005. Migration timing and river survival of late-run Fraser River sockeye salmon estimated using radiotelemetry techniques. Transactions of the American Fisheries Society 134:1342-1365. Farrell, A. P., S. G. Hinch, S. J. Cooke, D. A. Patterson, G. T. Crossin, M. Lapointe, and M. T. Mathes. 2008. Pacific salmon in hot water: applying aerobic scope models and biotelemetry to predict the success of spawning migrations. Physiological Biochemistry and Zoology 81:697-708. Ferrari, M. R., J. R. Miller, and G. L. Russell. 2007. Modeling changes in summer temperature of the Fraser River during the next century. Journal of Hydrology 342:336-346.  126  Flett, P. A., G. V. D. Kraak, and J. F. Leatherland. 1996. Overripening as the cause of low survival to hatch in Lake Erie coho salmon (Oncorhynchus kisutch) embryos. Canadian Journal of Zoology 74:851-857. Gilhousen, P. 1990. Prespawning mortalities of sockeye salmon in the Fraser River system and possible causal factors. International Pacific Salmon Fisheries Commission Bulletin 26. Goniea, T. M., M. L. Keefer, T. C. Bjornn, C. A. Peery, D. H. Bennett, and L. C. Stuehrenberg. 2006. Behavioral thermoregulation and slowed migration by adult fall Chinook salmon in response to high Columbia River water temperatures. Transactions of the American Fisheries Society 135:408-419. Hanson, K. C., S. J. Cooke, S. G. Hinch, G. T. Crossin, D. A. Patterson, K. K. English, M. R. Donaldson, J. M. Shrimpton, G. Van der Kraak, and A. P. Farrell. 2008. Individual variation in migration speed of upriver-migrating sockeye salmon in the Fraser River in relation to their physiological and energetic status at marine approach. Physiological and Biochemical Zoology 81:255-268. Hinch, S. G., S. J. Cooke, M. C. Healey, and A. P. Farrell. 2006. Behavioral physiology of fish migrations: Salmon as a model approach. Pages 239-295 in K. Sloman, S. Balshine, and R. Wilson, editors. Fish physiology volume 24: Behavior and physiology of fish. Elsevier Press, New York, NY. Hinch, S. G., and P. S. Rand. 1998. Swim speeds and energy use of upriver-migrating sockeye salmon (Oncorhynchus nerka): Role of local environment and fish characteristics. Canadian Journal of Fisheries and Aquatic Sciences 55:1821-1831. Hodgson, S., and T. P. Quinn. 2002. The timing of adult sockeye salmon migration into fresh water: Adaptations by populations to prevailing thermal regimes. Canadian Journal of Zoology 80:542-555. Houston, A. H. 1990. Blood and circulation. in C. B. Shreck, and P. B. Moyle, editors. Methods for fish biology. American Fisheries Society, Bethesda, MD. Hyatt, K. D., M. M. Stockwell, and D. P. Rankin. 2003. Impact and adaptation responses of Okanagan River sockeye salmon (Oncorhynchus nerka) to climate variation and change effects during freshwater migration: Stock restoration and fisheries management implications. Canadian Water Resources Journal 28:689-713. Jolly, G. M. 1982. Mark-recapture models with parameters constant in time. Biometrics 38:301-321. Keefer, M. L., C. A. Peery, and M. J. Heinrich. 2008. Temperature-mediated en route migration mortality and travel rates of endangered Snake River sockeye salmon. Ecology of Freshwater Fish 17:136-145.  127  Lee, C. G., A. P. Farrell, A. Lotto, M. J. MacNutt, S. G. Hinch, and M. C. Healey. 2003. The effect of temperature on swimming performance and oxygen consumption in adult sockeye (Oncorhynchus nerka) and coho (O. kisutch) salmon stocks. Journal of Experimental Biology 206:3239-3251. Leonard, J. B. K., M. Iwata, and H. Ueda. 2001. Seasonal changes of hormones and muscle enzymes in adult lacustrine masu (Oncorhynchus masou) and sockeye salmon (O. nerka). Fish Physiology and Biochemistry 25:153-163. Macdonald, J. S., M. G. G. Foreman, T. Farrell, I. V. Williams, J. Grout, A. Cass, J. C. Woodey, H. Enzenhofer, W. C. Clarke, R. Houtman, E. M. Donaldson, and D. Barnes. 2000. The influence of extreme water temperatures on migrating Fraser River sockeye salmon (Oncorhynchus nerka) during the 1998 spawning season. Canadian Technical Report of Fisheries and Aquatic Sciences 2315:39-57. Mathes, M. T., S. G. Hinch, S. J. Cooke, Crossin, G. T., D. A. Patterson, A. G. Lotto, and A. P. Farrell. 2009. Effect of water temperature, timing, physiological condition and lake thermal refugia on migrating adult Weaver Creek sockeye salmon (Oncorhynchus nerka). Canadian Journal of Fisheries and Aquatic Sciences, in press. McCullough, D., S. Spalding, D. Sturdevant and M. Hicks. 2001. Summary of technical literature examining the physiological effects of temperature on salmonids. United States Environmental Protection Agency, EPA-910-D-01-005, 114 pp. Neave, F. 1964. Ocean migrations of Pacific salmon. Journal of the Fisheries Research Board of Canada 21:1227-1244. Newell, J. C., and T. P. Quinn. 2005. Behavioral thermoregulation by maturing adult sockeye salmon (Oncorhynchus nerka) in a stratified lake prior to spawning. Canadian Journal of Zoology 83:1232-1239. Ng, T. B., and D. R. Idler. 1983. Yolk formation and differentiation in teleost fishes. Fish Physiology 9:373-404. Pankhurst, N. W., G. J. Purser, G. Van Der Kraak, P. M. Thomas, and G. N. R. Forteath. 1996. Effect of holding temperature on ovulation, egg fertility, plasma levels of reproductive hormones and in vitro ovarian steroidogenesis in the rainbow trout, Oncorhynchus mykiss. Aquaculture 146:277-290. Patterson, D. A., J. S. Macdonald, K. M. Skibo, D. P. Barnes, I. Guthrie, and J. Hills. 2007. Reconstructing the summer thermal history for the lower Fraser River, 1942 to 2006, and implications for adult sockeye salmon (Oncorhynchus nerka) spawning migration. Canadian Technical Report of Fisheries and Aquatic Sciences 2724:vii+43p.  128  Ramstad, K. M., and C. A. Woody. 2003. Radio tag retention and tag-related mortality among adult sockeye salmon. North American Journal of Fisheries Management 23:978-982. Sato, A., H. Ueda, M. Fukaya, M. Kaeriyama, Y. Zohar, A. Urano, and K. Yamauchi. 1997. Sexual differences in homing profiles and shortening of homing duration by gonadotropin-releasing hormone analog implantation in lacustrine sockeye salmon (Oncorhynchus nerka). Zoological Science 14:1009-1014. So, Y. P., D. R. Idler, and S. V. Hwang. 1985. Plasma vitellogenin in landlocked Atlantic salmon (Salmo salar Ouananiche): Isolation, homologous radioimmunoassay and immunological cross reactivity with vitellogenin from other teleosts. Comparative Biochemistry and Physiology 81B:63-71. Standen, E. M., S. G. Hinch, M. C. Healey, and A. P. Farrell. 2002. Energetic costs of migration through the Fraser River Canyon, British Columbia, in adult pink (Oncorhynchus gorbuscha) and sockeye (Oncorhynchus nerka) salmon as assessed by EMG telemetry. Canadian Journal of Fisheries and Aquatic Sciences 59:18091818. Stockner, J. G. and K. S. Shortreed. 1983. A comparative limnological survey of 19 sockeye salmon (Oncorhynchus nerka) nursery lakes in the Fraser River system, British Columbia. . Canadian Technical Report of Fisheries and Aquatic Sciences 1190:iv+63p. Teo, S. L. H., A. Boustany, H. Dewar, M. J. W. Stokesbury, K. C. Weng, S. Beemer, A. C. Seitz, C. J. Farwell, E. D. Prince, and B. A. Block. 2007. Annual migrations, diving behavior, and thermal biology of Atlantic bluefin tuna, Thunnus thynnus, on their Gulf of Mexico breeding grounds. Marine Biology 151:1-18. Truscott, B., D. R. Idler, Y. P. So, and J. M. Walsh. 1986. Maturational steroids and gonadotropin in upstream migratory sockeye-salmon. General and Comparative Endocrinology 62:99-110. Wagner, G. N., L. J. Kuchel, A. Lotto, D. A. Patterson, J. M. Shrimpton, S. G. Hinch, and A. P. Farrell. 2006. Routine and active metabolic rates of migrating adult wild sockeye salmon (Oncorhynchus nerka Walbaum) in seawater and freshwater. Physiological and Biochemical Zoology 79:100-108. Wallman, H. L., and W. A. Bennett. 2006. Effects of parturition and feeding on thermal preference of Atlantic stingray, Dasyatis sabina (Lesueur). Environmental Biology of Fishes 75:259-267. Welch, D. 2007. Final report: Investigations to determine the cause of early entry migration behavior for adult late-run Fraser River sockeye (Kintama Component).  129  Report to Southern Boundary Restoration and Enhancement Fund, Pacific Salmon Commission, Vancouver, BC, 44 pp. Young, D. B., and C. A. Woody. 2007. Dynamic in-lake spawning migrations by female sockeye salmon. Ecology of Freshwater Fish 16:155-164. Young, J. L., S. G. Hinch, S. J. Cooke, G. T. Crossin, D. A. Patterson, A. P. Farrell, G. Can Der Kraak, A. G. Lotto, A. Lister, M. C. Healey, and K. K. English. 2006. Physiological and energetic correlates of en route mortality for abnormally early migrating adult sockeye salmon (Oncorhynchus nerka) in the Thompson River, British Columbia. Canadian Journal of Fisheries and Aquatic sciences 63:10671077.  130  CHAPTER 6: Conclusions Sockeye salmon are renowned for long reproductive migrations from the high seas, through coastal waters, and up freshwater rivers before reaching natal spawning tributaries. My thesis research examined the final portion of this spawning migration, once fish have reached their natal watershed, and was carried out in a system affected by hydroelectric development. My research had three main objectives. The first was to quantitatively review the literature in order to assess the way that previous studies have evaluated the effectiveness of fishways and other passage facilities. The second was to evaluate the impact of a dam and fishway on the migration and survival of a population of sockeye salmon. Specifically, Chapter 3 assessed fishway passage success and postpassage consequences on survival. Chapter 4 examined how changes in water discharge from a dam affect the attraction of sockeye into the fishway. The third objective concerned the in-lake portion of spawning migration. Sockeye salmon migrating through large stratified lakes were used to investigate physiological factors that are related to thermoregulatory behaviour in adult salmon. My research evaluating the impact of hydroelectric facilities and the effectiveness of the fishway on the Seton River has implications for future research and management in the study area, as well as broader implications in the field of fish passage science. As demonstrated by my quantitative literature review, most scientific evaluations of fishways do not assess mechanisms of passage failure, or post-passage consequences that may affect survival or fitness. For this reason, current approaches to monitoring and evaluation are not sufficient to mitigate effects of barriers of fish populations (CastroSantos et al., 2009; Roscoe and Hinch, 2009). One of the important outcomes of my field study was the finding the Seton fishway, which is fairly effective compared to many in existence, may cause post-passage effects that decrease survival. Thus, it is possible that other fish passage facilities have post-passage consequences that reduce survival or fitness. Therefore, collectively my literature review and field study at Seton dam should provide the impetus for more rigorous evaluations of passage facilities elsewhere. The telemetry study demonstrates how an experimental approach that transports and releases  131  fish in different locales can be employed in such studies, in order to quantify mortality or sub-lethal costs associated with various passage routes, structures, or sections of the migratory route. The fact that Gates Creek sockeye are a threatened population (State of the Salmon, 2009) suggests a need to improve passage at Seton dam so that more fish are able to pass, and passage occurs without consequences to fitness or survival. My telemetry study corroborates the previous finding that passage failure is mostly associated with poor attraction to the fishway entrance (Pon et al., 2009). Because we observed considerable delay (>24 hours) below the dam for some fish, and high mortality in fish that were transported downstream and had to re-ascend the fishway, it is possible that swimming in fast turbulent flows in the tailrace of Seton dam also contributed to reduced survival following fishway passage. Therefore, based on my studies and Pon et al.’s (2009) previous work, I conclude that mitigation measures intended to reduce the impact of hydroelectric facilities would best be directed at improving passage conditions in the tailrace of the dam and entrance of the fishway. To that end, Chapter 4 illustrates the importance of water discharge and suggests that manipulation of spill discharge from the dam may be an effective management tool to improve passage, as has previously been suggested by others for this locale (Pon et al., 2009) and elsewhere (Leman and Paulik, 1966). Because my analysis of the effects of discharge examined only a few discharge levels and had small numbers of fish, I am not able to recommend a particular discharge that optimizes fishway passage. However, my results do suggest that very high discharges should be avoided whenever possible, and highlight the need top conduct further studies that assess how varying discharge affects hydraulic patterns and migratory behaviour of salmon. Across all release groups in my study, I observed considerable mortality within the natal watershed prior to reaching spawning areas. Although some mortality was attributed to fishway passage failure, many fish were also assumed to have died of ‘natural’ causes either before reaching the dam, or within the lakes after release upstream of the dam. Few previous studies have monitored behaviour and survival within the natal  132  sub-watersheds but it may be that levels of mortality of sockeye salmon in these areas are high in other populations as well. If this is the case, previous studies which consider fish that reach the mouth of the natal tributary to be successful migrants (English et al., 2005; Naughton et al., 2005) may underestimate levels of en route mortality. My results also can be related to the wider body of literature assessing mechanisms of migration mortality in Pacific salmon. Since other researchers have shown that fish that behave abnormally or fail to reach spawning grounds often exhibit high levels of physiological stress, low energy reserves, or advanced reproductive status (Cooke et al., 2006; Young et al., 2006), I also used non-lethal physiological biopsies to assess the condition of all study fish, and relate measures of stress to behaviour and mortality. However, I found no evidence that passage failure or mortality were related to physiological stress or exhaustion. Because I caught all fish at the top of the fishway, I could have been selecting for fish that were in good condition and as a consequence were better able to locate and ascend the fishway compared to fish in poor condition. If this was the case, then it would have impaired my ability to detect physiological mechanisms of passage failure and mortality. Nonetheless, physiological sampling of all fish in my study proved useful in evaluating the effects of transportation and handling of fish, and this approach is recommended to other researchers carrying out performance evaluations of fishways and other tagging studies. As opposed to mortality related to stress or poor physiological condition, mortality in the Seton system may have been more related to behavioural responses to environmental conditions, such as water discharge from the dam. Although some fish passed the dam quickly, others were delayed for a significant time or failed to pass at all. One possible explanation for individuals that failed to pass and dropped back downstream is that these fish sought alternate passage routes. Complex flows are often associated with wandering or searching behaviour, likely to seek out sustained directional flow or alternate passage routes (Hinch et al., 2002; Scruton et al., 2007). Salmonids are known to seek alternate passage routes at natural or anthropogenic barriers (Lucas and Baras, 2001). Thus, disappearance of sockeye in the Seton River could be related to seeking  133  alternate passage routes after failing to locate the fishway entrance. Future research should examine the hypothesis that after some amount of delay, fish may seek alternate passage-routes, and by doing so fail to pass a barrier and successfully reach upstream spawning areas. Pacific salmon have been used as models to examine the physiological cues and control of fish migrations (Hinch et al., 2006). My examination of in-lake behaviour of sockeye extends this line of research and provides the first data linking individual variation in thermoregulatory behaviour to physiological condition. Newell and Quinn (2005) previously proposed the hypothesis that the narrow range of temperatures occupied by sockeye salmon in Lake Washington represented a tradeoff that reduced metabolic energy expenditure and optimized reproductive maturation. My study lends support to the notion that temperature preference of sockeye salmon is related to energy and reproductive status, since I found that temperature experience was related to gross somatic energy and the reproductive hormone estradiol. Sample sizes for associations between temperature experience and energy and hormones were small (7 females, 14 males), due in part low recovery rates of archival temperature loggers. Future studies examining thermal ecology of migrating salmon may benefit from the use of temperature sensing telemetry, since data is transmitted to receivers, eliminating the need to relocate fish. For this reason, telemetry can be used to assess the temperature experience of fish that die before reaching spawning areas which is an important area for future research, given the strong influence of temperature on mortality (Crossin et al., 2008; Farrell et al., 2008; Keefer et al., 2008) and the importance of thermal refugia to survival (Goniea et al., 2006; Mathes et al., in press). Further studies identifying thermal habitats utilized by migrating salmon for final reproductive maturation or as cool-water refuges is likely to become more important in the context of forecasted increasing water temperatures associated with global climate change (Morrison et al., 2002; Ferrari et al., 2007).  134  References Castro-Santos, T., A. Cotel, and P. W. Webb. 2009. Fishway evaluations for better bioengineering: An integrative approach. in A. Haro, K. L. Smith, R. A. Rulifson, C. M. Moffit, R. J. Klauda, M. J. Dadswell, R. A. Cunjak, J. E. Cooper, K. L. Beal, and T. S. Avery, editors. Challenges for diadromous fishes in a dynamic global environment. American Fisheries Society Symposium, Bethesda, MD (in press). Cooke, S. J., S. G. Hinch, G. T. Crossin, D. A. Patterson, K. K. English, M. C. Healey, J. M. Shrimpton, G. Van Der Kraak, and A. P. Farrell. 2006. Mechanistic basis of individual mortality in Pacific salmon during spawning migrations. Ecology 87:1575-1586. Crossin, G. T., S. G. Hinch, S. J. Cooke, D. W. Welch, D. A. Patterson, S. R. M. Jones, A. G. Lotto, R. A. Leggatt, M. T. Mathes, J. M. Shrimpton, G. Van der Kraak, and A. P. Farrell. 2008. Exposure to high temperature influences the behaviour, physiology, and survival of sockeye salmon during spawning migration. Canadian Journal of Zoology 86:127-140. English, K. K., W. R. Koski, C. Sliwinski, A. Blakley, A. Cass, and J. C. Woodey. 2005. Migration timing and river survival of late-run Fraser River sockeye salmon estimated using radiotelemetry techniques. Transactions of the American Fisheries Society 134:1342-1365. Farrell, A. P., S. G. Hinch, S. J. Cooke, D. A. Patterson, G. T. Crossin, M. Lapointe, and M. T. Mathes. 2008. Pacific salmon in hot water: applying aerobic scope models and biotelemetry to predict the success of spawning migrations. Physiological Biochemistry and Zoology 81:697-708. Ferrari, M. R., J. R. Miller, and G. L. Russell. 2007. Modeling changes in summer temperature of the Fraser River during the next century. Journal of Hydrology 342:336-346. Goniea, T. M., M. L. Keefer, T. C. Bjornn, C. A. Peery, D. H. Bennett, and L. C. Stuehrenberg. 2006. Behavioral thermoregulation and slowed migration by adult fall Chinook salmon in response to high Columbia River water temperatures. Transactions of the American Fisheries Society 135:408-419. Hinch, S. G., S. J. Cooke, M. C. Healey, and A. P. Farrell. 2006. Behavioral physiology of fish migrations: Salmon as a model approach. Pages 239-295 in K. Sloman, S. Balshine, and R. Wilson, editors. Fish physiology volume 24: Behavior and physiology of fish. Elsevier Press, New York, NY. Hinch, S. G., E. M. Standen, M. C. Healey, and A. P. Farrell. 2002. Swimming patterns and behaviour of upriver-migrating adult pink (Oncorhynchus gorbuscha) and  135  sockeye (O. nerka) salmon as assessed by EMG telemetry in the Fraser River, British Columbia, Canada. Hydrobiologia 483:147-160. Keefer, M. L., C. A. Peery, and M. J. Heinrich. 2008. Temperature-mediated en route migration mortality and travel rates of endangered Snake River sockeye salmon. Ecology of Freshwater Fish 17:136-145. Leman, B. and G. J. Paulik. 1966. Spill pattern manipulation to guide migrant salmon upstream. Transactions of the American Fisheries Society 95:397-407. Lucas, M. C. and E. Baras. 2001. Migration of Freshwater Fishes. Blackwell Science, Malden, MA. Mathes, M. T., S. G. Hinch, S. J. Cooke, Crossin, G. T., D. A. Patterson, A. G. Lotto, and A. P. Farrell. 2009. Effect of water temperature, timing, physiological condition and lake thermal refugia on migrating adult Weaver Creek sockeye salmon (Oncorhynchus nerka). Canadian Journal of Fisheries and Aquatic Sciences, in press. Morrison, J., M. C. Quick, and M. G. G. Foreman. 2002. Climate change in the Fraser River watershed: flow and temperature projections. Journal of Hydrology 263:230244. Naughton, G. P., C. C. Caudill, M. L. Keefer, T. C. Bjornn, L. C. Stuehrenberg, and C. A. Peery. 2005. Late-season mortality during migration of radio-tagged adult sockeye salmon (Oncorhynchus nerka) in the Columbia River. Canadian Journal of Fisheries and Aquatic Sciences 62:30-47. Newell, J. C., and T. P. Quinn. 2005. Behavioral thermoregulation by maturing adult sockeye salmon (Oncorhynchus nerka) in a stratified lake prior to spawning. Canadian Journal of Zoology 83:1232-1239. Pon, L. B., S. G. Hinch, S. J. Cooke, D. A. Patterson, and A. P. Farrell. 2009a. A comparison of the physiological condition of migrant adult sockeye salmon and their attraction into the fishway at Seton River dam, British Columbia under three operational water discharge rates. North American Journal of Fisheries Management, in press. Roscoe, D. W. and S. G. Hinch. 2009. Effectiveness monitoring of fish passage facilities: historical trends, geographic patterns and future directions. Fish and Fisheries, in press. Scruton, D. A., C. J. Pennell, C. E. Bourgeois, R. F. Goosney, T. R. Porter, and K. D. Clarke. 2007. Assessment of a retrofitted downstream fish bypass system for wild Atlantic salmon (Salmo salar) smolts and kelts at a hydroelectric facility on the Exploits River, Newfoundland, Canada. Hydrobiologia 582:155-169.  136  State of the Salmon. 2009. Red list assessment of sockeye salmon (Oncorhynchus nerka). Report for the International Union for the Conservation of Nature’s Salmonid Specialist Group, 29p. Young, J. L., S. G. Hinch, S. J. Cooke, G. T. Crossin, D. A. Patterson, A. P. Farrell, G. Can Der Kraak, A. G. Lotto, A. Lister, M. C. Healey, and K. K. English. 2006. Physiological and energetic correlates of en route mortality for abnormally early migrating adult sockeye salmon (Oncorhynchus nerka) in the Thompson River, British Columbia. Canadian Journal of Fisheries and Aquatic sciences 63:10671077.  137  

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