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Ecosystem models of Northern British Columbia for the time periods 2000, 1950, 1900 and 1750 Ainsworth, Cameron; Heymans, Johanna J. (Sheila); Pitcher, Tony; Vasconcellos, Marcelo 2002

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A</928<2/!=2:182!G2/2@8-9!G2H.81/!!0110'''2/345%'61'''7458%&'9'!!!!,-./0/123!4.526/!.7!!$.81928:!;8<1</9!=.6>3?<@!A.8!B92!B<32!C28<.5/!!+DDDE!%&FDE!%&DD!@:5!%*FD!!!!!!!!!!     !A</928<2/!=2:182E!I:<J28/<10!.7!;8<1</9!=.6>3?<@E!=@:@5@!"##$!%%&'()*+* ECOSYSTEM MODELS OF NORTHERN BRITISH COLUMBIA FOR THE TIME PERIODS 2000, 1950, 1900 AND 1750                by  Cameron Ainsworth,   Johanna J. (Sheila) Heymans,   Tony J. Pitcher  and  Marcelo Vasconcellos    41 pages © published 2002 by   The Fisheries Centre, University of British Columbia  2204 Main Mall Vancouver, B.C., Canada 2002   ISSN 1198-6727 !ECOSYSTEM MODELS OF NORTHERN BRITISH COLUMBIA FOR THE TIME PERIODS 2000, 1950, 1900 AND 1750  By   Cameron Ainsworth, Johanna J. (Sheila) Heymans, Tony J. Pitcher and Marcelo Vasconcellos   2002   Fisheries Centre Research Reports 10(4), 41pp.   CONTENTS Page Director’s Foreword ............................................................................................... 3 Abstract.................................................................................................................. 4 Introduction........................................................................................................... 4 Model Groups......................................................................................................... 4 1) Sea Otters .............................................................................................................................. 4 2) Mysticetae ............................................................................................................................. 5 3) Odontocetae .......................................................................................................................... 5 4) Seals and sea lions ................................................................................................................ 5 5) Seabirds................................................................................................................................. 6 6) Transient (migratory) salmon............................................................................................... 6 7-8) Coho and chinook salmon ................................................................................................. 7 9-10) Juvenile and adult squid..................................................................................................8 11) Ratfish.................................................................................................................................. 9 12) Dogfish ................................................................................................................................ 9 13-14) Juvenile and adult pollock ........................................................................................... 10 15-16) Forage fish and eulachon.............................................................................................. 10 17-18) Juvenile and adult herring ............................................................................................11 19-20) Pacific ocean perch: juvenile and adult ........................................................................11 21) Inshore rockfish................................................................................................................. 12 22-23) Piscivorous rockfish: juvenile and adult ..................................................................... 12 24-25) Planktivorous rockfish: juvenile and adult.................................................................. 13 26-27) Juvenile and adult turbot (arrowtooth flounder)........................................................ 14 28-29) Juvenile and adult flatfish........................................................................................... 14 30-31) Juvenile and adult halibut ............................................................................................15 32-33) Juvenile and adult Pacific cod ......................................................................................15 34-35) Juvenile and adult sablefish ........................................................................................ 16 36-37) Juvenile and adult lingcod........................................................................................... 16 38) Shallow-water benthic fish ................................................................................................17 39) Skates .................................................................................................................................17 40-41) Large and small crabs .................................................................................................. 18 42) Commercial shrimp .......................................................................................................... 18 43-45) Epifaunal, infaunal carnivorous and detritivorous invertebrates............................... 18 46) Carnivorous jellyfish ......................................................................................................... 19 47-48) Euphausiids and copepods.......................................................................................... 19 49) Corals and sponges ...........................................................................................................20 Ecosystem Models of Northern BC, Past and Present, Page 2  50) Macrophytes ..................................................................................................................... 20 51) Phytoplankton................................................................................................................... 20 52) Discards ............................................................................................................................ 20 53) Detritus............................................................................................................................. 20 Balancing the Models ...........................................................................................20 Acknowledgements............................................................................................... 21 References............................................................................................................ 23 Appendices........................................................................................................... 24 Appendix A. Bycatch and discards ......................................................................................... 24 Appendix B. Parameter estimation..........................................................................................25 Appendix C. Parameters Used in models ............................................................................... 28 Appendix D. Diet matrices...................................................................................................... 29 Appendix E. Non-market prices ............................................................................................. 36 Appendix F. Landings..............................................................................................................37 Appendix G. Group definitions............................................................................................... 40                   A Research Report from ‘Back to the Future: the Restoration of Past Ecosystems as Policy Goals for Fisheries’ Supported by the Coasts Under Stress ‘Arm 2’ Project A Major Collaborative Research Initiative of the Canadian Government   41 pages © Fisheries Centre, University of British Columbia, 2002     FISHERIES CENTRE RESEARCH REPORTS ARE ABSTRACTED IN THE FAO AQUATIC SCIENCES AND FISHERIES ABSTRACTS (ASFA) Back to the Future on Canada’s West Coast, Page 3  DIRECTOR’S FOREWORD  MORE THAN ONE ROUTE TO HEAVEN  Imagine a shipwreck after escaping from Moors in Morocco, being rescued by sailors from Sicily, meeting St Francis of Assisi, delivering a brilliant impromptu address, and eventually taking over as head of the new Franciscan order after St Francis’ death in 1226. This is the life story of a remarkable Portuguese man, Saint Antony of Padua (1195 - 1231), the Patron Saint of Lisbon, and an excuse for an annual festival in that city every June 13th.  St Antony inherited both the vow of utter poverty, and St Francis’ trick of getting animals to listen to him. His logic and style made him particularly effective in converting educated heretics -  there were a lot of those in 13th century Italy – and in a sermon at Rimini he is reputed to have rebuked inattentive heretics by extolling the good behaviour of fishes in schools. In one version, he actually preaches to the fish (Figure 1). In an era where advanced science and technology under Islam were an unspoken challenge to the meager achievements of Christianity at the end of the Dark Ages, many were tempted to experiment with amalgams of the two religions (the Knights Templar are an example of this). St Antony’s message was that you can only have one religion (i.e., his) if you want to reach heaven.  But, as Dr Villy Christensen has pointed out, ECOPATH Models are not like religion, you are allowed to have more than one on your route to mass-balance heaven. Hence, this report, and its companion volume on Newfoundland, presents 4 different ECOPATH models for each of the west and east coasts of Canada.  The models describe the state of the marine ecosystem at four snapshots in time, from the present day to a time long past before contact of aboriginal peoples with Europeans. In the case of Northern British Columbia, these times are 2000; 1950, before modern catch data were kept; 1900, before the major expansion of industrial fisheries; and 1750, probably before Europeans arrived.  This material is the culmination of 2 years of work, and represents our best shot at describing the recent and historical past in these two environments. Doubtless, all of these models can be further improved, but these versions embody our closest approach to the perfection of ‘heaven’ to date. At a later stage, the more recent of the models can be tuned using their ability to emulate historical estimates of biomass from surveys, VPAs and the like, but this process is unlikely to be possible before such estimates began around 1950. The older ecosystem models have to rely on the constraints imposed by mass-balance itself, and as such, they are less certain than the recent models.  Information used in the models has derived from the workshops reported in Pitcher et al. (2002), and on further consultations with experts on each group on both coasts. In addition, a great of archival and historical material have been sifted and used wherever possible to  improve the biomass. For example, compared to the ancient past, some animals have gone locally extinct (e.g. walrus in Newfoundland). The static mass-balance models model reported here will be employed as baselines in dynamic simulations using Ecosim, aimed at determining what fisheries might be sustained by each of these marine ecosystems were they to be restored today - part of the Back to the Future policy research method.  Further information about Back to the Future research may be found on the web site www.fisheries.ubc.ca/projects/btf. This report forms part of the research output from the Coasts Under Stress (Arm 2) project, a Major Collaborative Research Initiative of the Canadian Government, led by Dr Rosemary Ommer.  The Fisheries Centre Research Reports series publishes results of research work carried out, or workshops held, at the UBC Fisheries Centre. The series focusses on multidisciplinary problems in fisheries management, and aims to provide a synoptic overview of the foundations, themes and prospects of current research. Fisheries Centre Research Reports are distributed to appropriate workshop participants or project partners, and are recorded in the Aquatic Sciences and Fisheries Abstracts. A full list appears on the Fisheries Centre's Web site, www.fisheries.ubc.ca, from where copies of most reports may be downloaded free of charge. Paper copies are available on request for a modest cost-recovery charge.  Tony J. Pitcher Professor of Fisheries &  Director, UBC Fisheries Centre  Pitcher, T., Heymans, J.J., Vasconcellos, M. (eds) (2002) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports 10(1), 116 pp   St Antony of Padua Preaching to the Fishes At Rimini, a 3m-wide panel of azulejos, blue ceramic tiles (Moorish technology) for which the Portuguese are justly famous. The panel is located just behind the main door of the Church of St Antony in Alfama, an old Moorish district of Lisbon. St Antony’s skill as a Franciscan preacher is evident from the attentive deportment of the fishes, compared to the unruly line of Italian heretics on the bridge behind. Ecosystem Models of Northern BC, Past and Present, Page 4  ABSTRACT Four Ecopath with Ecosim models were constructed to represent the marine ecosystem of northern British Columbia as it appeared in the years 1750, 1900, 1950 and 2000. The time periods were selected to characterize distinct epochs in the progression of exploitation and ecosystem structure (as required under Back to the Future methodology). Historical, archival and archeological information were used to construct the past models, as well as traditional ecological knowledge gained from community interviews. Approximately 150 species and genera are included, with many more implicit in the models. These players are grouped into 53 functional model groups, arranged by trophic similarity and habitat preference; special distinction is given to commercially important animals. Biomass, production, consumption and diet are among the parameters used to describe each group, as well as period-appropriate fisheries, bycatch and discards. The static Ecopath models described in this report represent the basis of dynamic Ecosim models, which can be used to test hypotheses regarding ecosystem structure/function and management strategies.  INTRODUCTION The 2000, 1950, 1900 and 1750s models of Hecate Strait were adapted from Beattie (2001) with some changes to the model structure to satisfy the aims of the “Coasts Under Stress” project. The total area of the ecosystem being modelled is approximately 70,000 km2. The model suggested by Beattie (2001) was also adapted to include recreational fisheries for salmon, halibut, lingcod and inshore rockfish, as well as the inclusion of newer market prices and the bycatch for the shrimp trawl fisheries. Organisms that compose our functional groups are detailed in Appendix G. The changes in biomass are given over the four models in the description of each group, and the P/B and Q/B ratios of 2000 and 1950 were similar, while that of 1900 and 1750 were presumed to be similar. The biomass, P/B and Q/B estimates used in this model are given in Appendix C. Diet estimates for past models are based on the 2000 model, but have been adapted to include the differences in diet that would occur prior to large-scale commercial fishing. Final diet matrices are listed in Appendix D. Unless otherwise stated, values were left to be similar to that of the present day model. Landings are listed in Appendix F.   MODEL GROUPS 1) Sea Otters Sea otters have been part of the Hecate Strait ecosystem at the time of first contact, and were very important to First Nations people, thus we included them in these models. Sea otters are also making a comeback in some parts of British Columbia, and might be more important in the ecosystem in the future.  Vasconcellos and Pitcher (2002a) suggest that the biomass at present as well as in the 1900s (and 1950s) was very low. We assume a biomass of 0.1 kgkm-2, which might still be too high. For pre-contact estimates of sea otter biomass, Kenyon (1975) estimated the total virgin population size between 100,000 and 150,000 animals. Assuming that the Hecate Strait covers approximately 1/20th of sea otter coastal range, Vasconcellos and Pitcher (2002a) estimate a population size in the pre-contact period of approximately 5,000 animals for the Hecate Strait. With an average weight of 22.4 kg (Bodkin et al., 1998) the density of sea otters in the pre-contact period is estimated at 1.6 kgkm-2. Riedman and Estes (1998) suggested that the otter populations grew at a rate of about 15% per year during the early phase of their recovery. Only an annual increase of 13% could be accommodated as biomass accumulation in the 1950 model, because of limiting production. Bodkin et al. (1998) estimated an instantaneous mortality rate of 0.13 yr-1 based on an average age of 7 years in the Prince William Sound area. We use the same P/B ratio for the 1950, 1900 and 1750 models. Riedman and Estes (1998) estimated a consumption rate of between 23 and 33% per day (84-120 per year) for adults. We use the average (101.5 yr-1) as the Q/B for this compartment in all time period models. Riedman and Estes (1998) suggested that the diet of sea otters consists of 50% epifaunal invertebrates, 20% small crabs, 1% large crabs, 10% shallow water benthic fish, 10% juvenile pollock and 9% squid.  Irwin (1984) suggested that First Nations hunted sea otters with harpoons and clubs. It is assumed that prior to the intensive exploitation of sea otters that began around 1740, sustainable harvesting rates were adopted, in the order of the rate of population growth of 2.5% per year (Kenyon 1975), and we assume a catch of about 0.2 kgkm-2 for the 1750 model. According to Vasconcellos and Pitcher (2002a) sea otter kills in the early 1900s can be considered insignificant, Back to the Future on Canada’s West Coast, Page 5  and as they were nearly extinct by 1920 we assume that no other catches of sea otters were taken. 2) Mysticetae The baleen whales include the blue whale, fin whale, sei whale, humpback whale, right whale, and gray whale (Gregr 2002). Gregr (2002) gives population estimates for baleen whales and sperm whales. Using the mean weight per species from Trites and Pauly (1998), the biomasses of Mysticetae for the 2000, 1900 and 1750 time periods were calculated as 1.339 tkm-2, 1.54 tkm-2 and 2.67 tkm-2 respectively. The 1950 biomass was assumed to be the same as present day because whales were already depleted by that time according to Gregr (2002). Trites and Heise (1996) suggested that the P/B ratio should be half of the 4% maximum rate of population increase, thus we use a P/B ratio of 0.02 yr-1 and we use the same P/B ratio for all time periods (although it might be lower in the earlier models due to the larger blue and humpback whales that were present at that time). Trites and Heise (1996) suggested a Q/B ratio of 13 yr-1 in summer and 5.1 yr-1 in winter. For the 2000 and 1950 models we used the average between these ratios (9.1 yr-1) while for the 1900 and 1750 models, we used a value of 8 yr-1, to incorporate the larger blue and humpback whales that were present at that time. The diet of Mysticetae was adapted from Tables H and I in Trites and Heise (1996). Table 1 below shows their seasonal breakdown. See Appendix D Table D1 for diet matrix used in Ecopath. First Nations people harpooned Gray whales according to Irwin (1984), and if we assume that they caught about two per year, it gives a catch of approximately 0.5 kgkm-2yr-1 in the 1750 model. Gregr (2002) suggests that there was a limited catch of baleen whales from after WWII until 1967. Revised versions of these models will include a 1900 and (a much smaller) 1950 catch. 3) Odontocetae The toothed whales include the sperm whale, Baird’s beaked whale, northern right whale dolphin, Pacific white-sided dolphin, Dall’s porpoise, harbour porpoise and killer whale. Trites and Heise (1996) give the number of toothed whales (excluding sperm whales) and average weight of each species in Northern B.C. (Table 2). The average sperm whale biomass is approximately 19 tonnes (150 sperm whales according to Gregr, (2002)), thus the total biomass of toothed whales was 0.061 tkm-2. This value was used for present day and 1950. As in Beattie et al. (1999), we consider that the biomass of killer whales, dolphins and porpoises in the Hecate Strait was ca. 20% larger during the early 1900s than at present time (estimation based on fishers and aboriginal people. Gregr (2002) suggests that the number of sperm whales was similar at that time. Thus, the biomass in 1900 was estimated at 0.066 tkm-2 and we assume that the biomass in 1750 was the same as that of the early 1900s (see Appendix C). We assume that the P/B of toothed whales will be higher than that of baleen whales, but lower than that of seals and sea lions. A P/B of 0.04 yr-1 was adopted for all time periods. Trites and Heise (1996, Tables F and G) suggested a Q/B of 15.6 yr-1 for toothed whales in the summer and 15.3 yr-1 in the winter, thus an average of 15.5 yr-1 was used in all models. The diet of toothed whales was adapted from Beattie (2001) by assuming that 1/6th of the predation on forage fish was directed to eulachon (Vasconcellos and Pitcher 2002e).  4) Seals and sea lions The seals and sea lions in the Hecate Strait include Steller sea lions and harbour seals. Northern fur seals, northern elephant seals and California sea lions sometimes visit the northern parts of BC (Vasconcellos and Pitcher 2002b). Beattie (2001) suggested that the present biomass of seals and sea lions is approximately 0.052 tkm-2, and according to Vasconcellos and Pitcher (2002b), present biomass is approximately 75% of what it was around 1900, Table 1:  Seasonal diet of Mysticetae. Source: Trites and Heise (1996).  Compartment Summer Winter diet Average Post-Krill 0.043 0.316 0.180 0.226 Copepods 0.009 0.074 0.042 0.020 Bivalves 0.047 0.026 0.037 0.037 Polychaetes 0.047 0.026 0.037 0.037 Amphipods 0.844 0.471 0.658 0.658 Sandlance 0.002 0.026 0.014 0.014 Herring 0.008 0.061 0.035 0.100 Table 2:  Numbers, mean weight and biomass of toothed whales. Source: Trites and Heise (1996).  Species Weight (kg) Number Biomass (tonnes) Dall's porpoise 341 1000 341 Harbour porpoise 31 1000 31 Pacific white sided 79 2000 158 Northern right 412 100 41 Killer whales 2195 100 219 Transient killer whales 2195 34 75 Ecosystem Models of Northern BC, Past and Present, Page 6  thus the biomass in 1900 was approximately 0.069 tkm-2. Vasconcellos and Pitcher (2002b) also suggest that the number of seals and sea lions in B.C. increased during the late 1800s and early 1900s due to a reduction in the native population that hunted them, and therefore the biomass of seals and sea lions around 1750 was probably similar to what it is at present (0.05 tkm-2). Biomass in the 1950 model was based on 11,653 animals in British Columbia, an average of three estimates compiled by Pike (1958) (estimates were from Dept. Fish 1955, Dept. Fish 1956, Fish Res. Bd. 1956). Numbers were converted to biomass using average weight provided by Trites and Heise (1996). Vasconcellos and Pitcher (2002b) estimate a biomass accumulation of 3.5% per year from estimates of 25% for 1989-2000 done by Bigg (1985). Biomass accumulation was therefore calculated as 0.0018 tkm-2yr-1 for the 2000 model. Trites and Heise (1996) suggest that the maximum rate of population growth for pinnipeds is about 12% and the P/B for all models was assumed to be half that at 0.06 yr-1. The same authors estimate a Q/B for seals and sea lions of 15.3 yr-1 in summer and 14.8 yr-1 in winter. We use 15.1 yr-1 in all models.  The diet of seals and sea lions in the initial diet matrix were adapted from Trites and Heise (1996, Tables H and I) by assuming that 1/6th of the predation on forage fish was directed to eulachon (Vasconcellos and Pitcher, 2002e). Sharks were replaced with dogfish and hake with Pacific Ocean perch, as there aren’t many sharks or hake in Hecate Strait. The salmon and rockfish in the diet were also broken down according to the biomass estimates of their groups in the system for each of the four models. Appendix D Table D3 gives the final diet matrix. Seals and sea lions were hunted by First Nations people (Vasconcellos and Pitcher, 2002b), so we add a catch of 0.1 kgkm-2yr-1 to the 1750 model as no First Nations catch estimate is available. Further, seals are routinely shot during salmon gillnet operations according to Ainsworth (pers. comm.), although kills are rare. We added a value of 0.1 kgkm-2yr-1 to include this discard of seals by salmon gillnet fishermen. 5) Seabirds Seabirds present in the Hecate Strait include gulls, grebes, Cassin’s auklet, tufted puffin, common murre, rhinoceros auklet, marbled murrelet, pigeon guillemot, merganser spp., pelagic cormorants, sooty shearwater, northern fulmar, double-crested cormorant and the common loon (Kaiser, 2002). Although it would be preferable to differentiate between species that breed in the region and species that are non-breeding seasonal residents, and to differentiate between different trophic feeders (i.e. planktivores vs. piscivores), seabirds were kept in one group in this model. It would be advisable to make these changes in the next phase of the modeling. Kaiser (2002) suggests that until 1900 the effect of contact between native people and Europeans may have been of benefit to seabirds; they expanded as epidemic and cultural disaster overtook the native population, many parts of the coast became depopulated, and European foods became commonplace. However, in the twentieth century, human activity often had a negative impact on the marine birds of British Columbia (Kaiser 2002). Thus, it is assumed that the biomass of seabirds would be higher in 1900 than in 1750, or any subsequent years. Kaiser (2002) gives the biomass of seabirds that are currently feeding on the Hecate Strait as 516 tonnes (0.007 tkm-2), which is what we used for the 1750 model – and similar to Haggan et al. (1999) we double the 1750 biomass for the 1900 model (0.014 tkm-2). Biomass for the 1950 model was taken as an intermediate value, the average of 1900 and present day – this assumes a gradual transition. Wada and Kelson (1996) suggested a P/B of 0.1 yr-1 for seabirds and we use this ratio for all four time periods. Wada and Kelson (1996) suggested a Q/B for seabirds of 112 yr-1 in summer and 98.4 yr-1 in winter. We use the average (105.2 yr-1) in all four models. The diet of seabirds in the 2000 model was adapted from Beattie (2001) by dividing the 30% consumed by forage fish into 25% forage fish and 5% eulachon (Vasconcellos and Pitcher, 2002e) – listed in Appendix D Table D4. Discards were reduced to 0.3% from 1% to balance the model. For the 1750 model, the diet was adapted from p. 57 in Pauly et al. (1996) as no discards or detritus were consumed and the structure of the ecosystem was probably very different. Benthos in Pauly, Christensen et al. (1996) were divided into small crabs and epifaunal invertebrates, and small pelagics were divided into forage fish (50%), eulachon (15%), and adult/juvenile herring (15 and 20% respectively). Small and large herbivorous zooplankton was assumed to be copepods (Pauly, Christensen et al. 1996).  6) Transient (migratory) salmon Transient salmon include sockeye, chum and pink salmon, which migrate through the system on their way to spawning areas. Vasconcellos and Back to the Future on Canada’s West Coast, Page 7  Pitcher (2002c) use the ratio between catch and exploitation rate to calculate the biomass of transient salmon at 0.588, 0.754, 0.840 and 1.0 tkm-2 for 2000, 1950, 1900 and 1750 respectively. Newlands (1998) calculated a P/B value of 2.48 yr-1 for transient salmon and that is used for the 2000 and 1950 models. The P/B ratios for 1900 and 1750 (Table 3) were calculated as the sum of fishing mortality (F = Catch / Biomass) and natural mortality rate (determined in Appendix B Table B1). Christensen (1996) gave annual Q/B ratios for pink, sockeye and chum of 12.2, 4.6 and 8.2 yr-1 respectively, and an average of 8.33 yr-1 was used in the 2000 and 1950s models. The Q/B estimates for 1900 and 1750 were calculated in Appendix B Table B2 as approximately 3.72 yr-1.  Transient salmon feed mostly on zooplankton, but outside of the ecosystem. Migratory species such as these are problematic during dynamic simulations since the abundance of their food is independent of systemic fluctations. As for the static model detailed here, transient salmon must receive some diet to get the correct trophic level. Thus, we add 0.1% euphausiids and 0.05% amphipods to their diet, with the remaining 99.85% being imported to the system. The diet of transient salmon remained the same for all four models. Vasconcellos and Pitcher (2002) suggested that the average catch of transient salmon for 1995-1997 was approximately 29 thousand tonnes (0.412 tkm-2) and the same reference gives the proportion of catches by gear type in the Hecate Strait during 1997. Recreational catch is based on an unpublished DFO survey (2000) summarized in Forrest (2002). Table 4 shows the estimated catches of transient salmon in the 2000 model. The 1950 commercial catch for transient salmon (sockeye, pink and steelhead trout) was taken from DFO catch statistics (DFO 1995), representing total 1951 catch in 10 statistical areas that comprise Hecate Strait, Dixon Entrance and Queen Charlotte Islands. The historical record for transient salmon apportions catch into gillnets, seine and troll. The latter was split evenly in the model between salmon troll and salmon troll freezer. Together with a small recreational fishery (estimated by Forrest (2002)), total catch of transient salmon in 1950 was 0.398 tkm-2yr-1 (see Appendix F for catch information). Vasconcellos and Pitcher (2002c) estimate the catch of transient salmon in 1900-1905 to be 0.126 tkm-2yr-1. This value was used in the 1900 model. Chum and humpback salmon were fished by First Nations people with hook and line, harpoon, spear, traps (weir, stone weir) dip nets, basket traps, or fall traps, and eaten fresh and smoked, or dried (Irwin 1984). Hewes (1973) estimates that First Nations caught approximately 6,400 tonnes of salmon in pre-contact times and we opted to split this catch equally between transient (0.046 tkm-2yr-1) and resident salmon.  7-8) Coho and chinook salmon Beattie (2001) calculated the biomass for coho and chinook salmon in the 2000 model as 0.024 tkm-2 and 0.018 tkm-2 respectively. In the 1950 model, these were 0.067 tkm-2 and 0.026 tkm-2 respectively, based on the ratio between catch and exploitation rate offered by DFO historical statistics. Vasconcellos and Pitcher (2002 c) estimate a biomass decrease of ca. 70% and 85% of coho and chinook salmon between 1900 and the present, which gives biomasses of 0.08 tkm-2 and 0.12 tkm-2 for coho and chinook in 1900. Similarly, Vasconcellos and Pitcher (2002c) estimate that the biomass of coho and chinook salmon was 20% higher in the pre-contact period than in the early 1900s. Thus the biomass of coho and chinook in the pre-contact period is estimated at 0.096 tkm-2 and 0.144 tkm-2, respectively. We assume that both the coho and chinook populations are at present in an annual decline of around 10%, which gives negative biomass accumulations of -0.24 kgkm-2yr-1 and –0.18 kgkm-2yr-1 respectively in the 2000 model. No biomass accumulations were given for 1950, 1900 or 1750. Beattie (2001) uses monthly estimates of 23% and 18% respectively, for the increase in body size of coho and chinook (obtained from Newlands (1998)). This gives P/B ratios of 2.76 yr-1 for coho and 2.16 yr-1 for chinook, which we used for both the 2000 and 1950 models. However, fishing Table 3:  Estimation of P/B ratios for transient and resident salmon.   Biomass (tkm-2) Catch (tkm-2yr-1) F (year-1) M (year-1) P/B (year-1) Group 1900 1750 1900  1750  1900 1750  1900 1750 Transient 0.84 1.008 0.125 0.046 0.140 0.045 0.470 0.621 0.517 Coho  0.08 0.096 0.012 0.023 0.150 0.238 0.918 1.069 1.157 Chinook  0.12 0.144 0.019 0.023 0.156 0.159 0.207 0.363 0.366 Table 4:  Catches of transient salmon in the 2000 model. Gear Proportion catch Transient salmon catch (tkm-2) Gillnet 0.455 0.187 Seine 0.461 0.190 Troll 0.017 0.007 Troll freezer 0.067 0.028 Recreational  0.002 Total 1 0.414 Ecosystem Models of Northern BC, Past and Present, Page 8  mortality was much lower prior to commercial fishing (1750 and 1900 models) and therefore we used P/B ratios calculated from the sum of F and M, where F = Catch / Biomass and M is from Appendix B Table B1. Beattie (2001) suggests that the Q/B ratio of both coho and chinook should be calculated by Ecopath using a P/Q ratio of 0.2. This gives a Q/B ratio of 13.8 yr-1 and 10.8 yr-1 respectively for coho and chinook. Appendix B Table B2 shows Q/B ratios calculated for the 1900 and 1750 models. These are 3.99 yr-1 for coho and 2.82 yr-1 for chinook, lower than the 1950 and 2000 models because older individuals were more abundant at that time. The diet (for all models) of coho and chinook was adapted from Beattie (2001), eulachon having been extracted from the forage fish compartment. It was assumed that 1/6th of the predation on forage fish in Beattie (2001) was directed at eulachon (Vasconcellos and Pitcher, 2002e). See Appendix D Table D5 and D6 for coho and chinook diet information. Beattie (2001) gives a 2000 catch of 0.006 tkm-2yr-1 and 0.003 tkm-2yr-1 for coho and chinook salmon respectively. This was converted to the various gears in our model by using the proportion of catches by gear type in the Hecate Strait during 1997 (Vasconcellos and Pitcher 2002c) (Table 5). Recreational catch for both groups is based on unpublished data from a 2000 survey (Forrest 2002). There were 0.027 tkm-2yr-1 of chinook taken by the sport fishery in 2000, and 0.005 tkm-2yr-1of coho. The 1950 commercial catch was taken from DFO’s statistical catch record, representing the 1951 catch in 10 statistical areas that comprise Hecate Strait, Dixon Entrance and Queen Charlotte Islands (DFO 1995). The historical records for coho and chinook apportion catch for gillnet, seine and troll. The latter was split evenly in the model between salmon troll and salmon troll freezer fleets. Recreational catch in 1950 was assumed to be 9% of present day according to Forrest (2002). Total catches for coho and chinook in 1950, including recreational, are therefore 0.061 and 0.0214 tkm-2yr-1 respectively. Vasconcellos and Pitcher (2002c) suggest a catch of 0.012 tkm-2yr-1 for coho and 0.018 tkm-2yr-1 for chinook in 1900-1905. Hewes (1973) estimated that First Nations caught approximately 6,400 tonnes of salmon in pre-contact times; we opted to split this catch equally between transient and resident salmon (0.046 tkm-2yr-1 each). Further, we assumed that 50% of that catch came from coho and chinook respectively (thus 0.023 tkm-2yr-1 each in 1750). See Appendix F for complete catch information by time period. Beattie (2001) obtained values on discards of salmon from DFO’s observer program database for 1997 (see Appendix A Table A2). Discarded coho and chinook salmon in the 2000 model amounted to 0.038 tonnes and 0.684 tonnes, respectively, which calculates to discards of 0.001 kgkm-2yr-1 and 0.01 kgkm-2yr-1. 9-10) Juvenile and adult squid Squid were split into juvenile and adult compartments due to the overwhelming effect of cannibalism in the models. The biomasses of both juvenile and adult squid were estimated with the inclusion of an ecotrophic efficiency of 95% for all four models. Beattie (2001) used the P/B ratio (6.023 yr-1) of the flying squid Onychoteuthis borealijaponica, which is used for both juvenile and adult squid in all models. The same author calculates a Q/B ratio of 34.675 yr-1 for two other Loligo species (L. pealei, L. vulgaris) and we use this ratio for both juvenile and adult squid in all four models.  The diet of squid was adapted from Beattie (2001) by assuming that 1/6th of the predation on forage fish was directed at eulachon (Vasconcellos and Pitcher 2002e). The diet of adult squid remained the same for all four models, while that of juvenile squid was adapted with the addition of adult herring in the 1750 model to balance forage fish. Final diet matrices appear in Appendix D Table D7. Opal squid, Loligo opalescens, are at present fished primarily as bait for sablefish, crabs and halibut, by using primarily seine nets (DFO 1999g) while a new fishery for the neon flying squid Ommastrephes bartrami is currently being promoted (DFO 1999h), but has not yet acquired significance. A very small catch of 0.001 kgkm-2 was added to the herring seine fleet to represent the catch of adult squid. Squid are also taken and retained by the groundfish fishery (Beattie 2001) in the 2000 model – 0.022 kgkm-2 was recorded by the DFO observer program database for 1997. No squid were caught in the 1950s, 1900s or 1750s. Beattie (2001) obtained values on discards of squid of 0.002 kgkm-2 from DFO’s observer Table 5.  Catches by gear types for 2000.  Gear Proportion  by gear type Catch (tkm-2yr-1)  Coho Chinook Coho Chinook Gillnet 0.166 0.194 0.0010 0.0006 Seine 0.061 0.023 0.0004 0.0001 Troll 0.268 0.266 0.0016 0.0008 Troll freezer 0.505 0.512 0.0030 0.0015 Recreational   0.0012 0.0006 Total 1 1 0.0072 0.0036 Back to the Future on Canada’s West Coast, Page 9  program database for 1997 (see Appendix A Table A2).  11) Ratfish  The biomass of ratfish is not available for any of the time periods. Biomass for 1750 and 1900 was calculated by assuming an ecotrophic efficiency of 95%. However, the 1950 and 2000 biomass was assumed to be similar to the average biomass estimated from Fargo et al. (1990) for 1984-1987 (Beattie 2001) (Table 6). Beattie (2001) suggests that the P/B of ratfish should be similar to that of dogfish (0.099 yr-1), that was used for the 2000 and 1950 models. However, for the 1900 and 1750 models, the M of 0.199 yr-1, calculated in Appendix B Table B1 was used as the P/B of ratfish, as there was no fishery for the species during those two time periods. Beattie (2001) calculates a Q/B ratio for ratfish of 1.4 yr-1 using a Winf of 1000g and average temperature of 6oC. We use this value for all four models as no newer data are available. The diet composition obtained from Beattie (2001) was used in all four models and adapted by assuming that 1/6th of the predation on forage fish was directed to eulachon (Vasconcellos and Pitcher 2002e), and dividing the benthic invertebrates in Beattie (2001) into carnivorous and detritivorous invertebrates for our model structure. Ratfish is caught and retained by the groundfish fishery in the 2000 model (Beattie 2001) – 0.052 kgkm-2yr-1 was recorded by the DFO observer program database for 1997. No catch is recorded for ratfish in the DFO Commercial Catch Statistics record (DFO 1995). The 1950 catch was assumed to be negligible. Beattie (2001) obtained values on discards of ratfish by the groundfish trawl fisheries of ca. 0.01 tkm-2 from DFO’s observer program database for 1997 (see Appendix A Table A2). Hay et al. (1999) suggest that ratfish are caught as bycatch to the shrimp trawl fishery. We use the estimate obtained by Hay et al. (1999) for ratfish bycatch (0.01 tkm-2) as a discard from the ratfish compartment in the 2000 and 1950 models (See Appendix A Table A1).  12) Dogfish The estimate of dogfish biomass given by Beattie (2001) (0.909 tkm-2) is used for our 2000 model, while the biomass of dogfish in 1900 was calculated by assuming an ecotrophic efficiency of 72% (similar to that of the 2000 model) and the 1750 biomass (1.36 tkm-2) was assumed to be 50% higher than the biomass at present (Vasconcellos and Pitcher 2002d). The end of World War II saw a revived liver oil fishery for dogfish, especially along the East coast of the Queen Charlotte Islands (British Columbia History Supplement for Special Centennial Newspaper Editions, 1958). An arbitrary 40% reduction from the pre-contact abundance was assumed in the 1950 model, due to the post-war fishery. The biomass estimate used in the 1950 model was 0.8 tkm-2.  Beattie (2001) calculates a P/B ratio for dogfish in 2000 of 0.099 yr-1 from natural mortality (0.094 yr-1) obtained from Wood et al. (1979) and fishing mortality of 0.005 yr-1 obtained from the DFO Fishery Observer Database. This value was also used for 1950. However, the natural mortality of 0.11 yr-1 calculated in Appendix B Table B1 was used for the 1750 model and a fishing mortality of 0.03 yr-1 (similar to the 1950 and 2000 Fs) was added to give a P/B of 0.14 yr-1 for the 1900 model. The Q/B ratio used in the 2000 and 1950 models (2.72 yr-1) for dogfish was obtained from Beattie (2001), but for the 1900 and 1750 models, the Q/B calculated in Appendix B Table B2 (3.33 yr-1) was used. The diet obtained from Beattie (2001) was adapted for the 2000 and 1950 models by assuming that 1/6th of the predation on forage fish was directed to eulachon (Vasconcellos and Pitcher 2002e) and the proportion of the diet attributed to benthic invertebrates was divided into infaunal carnivorous invertebrates and infaunal invertebrate detritivores. Transient salmon was included in the diet of dogfish for these models, and the percentage of coho and chinook was reduced to balance those compartments.  The dogfish fishery started around 1872, and by 1900-1905 0.017 tkm-2was caught annually with longlines (Vasconcellos and Pitcher 2002d). By the 1940s they were being caught with longlines, trawlers and gillnets (Vasconcellos and Pitcher 2002d). In the 2000 model, longlines and trawlers mostly catch dogfish; DFO information indicates a catch of 0.0226 tkm-2yr-1 by longlines from 1995-1997 and 0.3 kgkm-2yr-1 caught as bycatch and retained by the groundfish trawl fishery during 1997 (Beattie 2001). As mentioned earlier, a post-war fishery had developed for these animals. Although no catch records are available, the 1950 catch was assumed Table 6:  Biomass of ratfish. Source: Fargo et al. (1990).  Year Standing crop (tonnes) 1984 28,644 1986 54,292 1987 14,157 Average 23,771 Biomass (tkm-2) 0.517 Ecosystem Models of Northern BC, Past and Present, Page 10  to be 150% of the present day value (0.0339 tkm-2yr-1total catch). Like the present day model, catch was divided between longline and groundfish trawl, the latter receiving about 1% of the total. Beattie (2001) obtained values on discards of dogfish by the groundfish trawl fisheries of 0.009 tkm-2yr-1 from DFO’s observer program database for 1997 (see Appendix A Table A2). Dogfish is also caught as bycatch (0.6 kgkm-2yr-1 see Appendix A Table A1) to the shrimp trawl fishery (Hay et al. 1999). There are no data available on discards by the salmon gillnet fishery, but some sets had more dogfish than salmon, and they were very often killed by the fishermen (Ainsworth, pers. comm.). An estimate of 2% of the salmon catch (or 0.008 tkm-2yr-1) is used as the discard of dogfish in the salmon gillnet fishery in the present day model. A total discard rate of 0.019 tkm-2yr-1is estimated for the 1950 model. This amount includes bycatch from the salmon gillnetting fleet (2% of salmon catch) and groundfish trawl fleet (same as in 2000 model). 13-14) Juvenile and adult pollock Walleye pollock was split into adult and juveniles to reduce cannibalism in the model. Beattie (2001) used the 11-22,000 tonnes of pollock in the Hecate Strait obtained from Saunders and Andrews (1996) and 37% of the pollock stock being juveniles (Niggol, 1982) to calculate both juvenile and adult walleye pollock biomasses of 0.132 tkm-2 and 0.359 tkm-2 respectively. These values are used in the 1950 and 2000 models. The biomass of adult and juvenile pollock was estimated for both the 1900 and 1750 models by assuming an ecotrophic efficiency of 95%. The estimates of P/B of 0.263 yr-1 for adults and 1.061 yr-1 for juvenile walleye pollock, obtained from Beattie (2001) were used for the 1950 and 2000 models, while the natural mortality estimates calculated in Appendix B Table B1 (adult = 0.15 yr-1, juvenile = 0.23 yr-1) were used as P/B estimates for the 1750 and 1900 models.  Beattie (2001) obtained a Q/B ratio of 1.168 yr-1 for adult pollock and 0.98 yr-1 for juveniles, but decided to have the Q/B for juveniles calculated (5.31 yr-1), by assuming a P/Q ratio of 20% as the Q/B for juveniles was too low. These ratios were used in the 2000 and 1950 models. The Q/B values estimated in Appendix B Table B2 were used for adult and juvenile pollock in 1900 and 1750. The diet estimates were obtained from Beattie (2001) (see Appendix D Table D10). Decapods, euphausiids and mysids were all assumed to be euphausiids, while larvaceans, amphipods and gastropods were considered to be epifaunal invertebrates. Fish was considered to be forage fish and split into 1/6th eulachon and 5/6th forage fish (Vasconcellos and Pitcher 2002e).  Groundfish trawlers catch 0.007 tkm-2yr-1 in the 2000 model after Beattie (2001) (see Appendix A Table A2). Beattie (2001) obtained values on discards of pollock by the groundfish trawl fisheries of 0.002 tkm-2yr-1 from DFO’s observer program database for 1997. Pollock is also caught as bycatch (0.0002 tkm-2yr-1, see Appendix A Table A1) to the shrimp trawl fishery (Hay et al. 1999). These values were included in the 1950 and 2000 models. 15-16) Forage fish and eulachon Forage fish consist mainly of sandlance, although pilchards, anchovy, capelin, chub mackerel, shad and smelts are also present (Beattie 2001). Eulachon was removed from this compartment and all diet references to forage fish were split into 1/6th eulachon and 5/6th forage fish (Vasconcellos and Pitcher 2002e). As with Beattie (2001) the biomass of forage fish was not available, and the biomass of both forage fish and eulachon in all four models were estimated by setting the ecotrophic efficiency of these compartments to 95%. Beattie (2001) uses the average of adult and juvenile herring P/B ratios for forage fish (1.432 yr-1). We use that value for forage fish and eulachon in our 1950 and 2000 models. The natural mortality calculated in Appendix B Table B1 for forage fish (0.595 yr-1) was used as its P/B ratio in the 1900 and 1750 models, while that calculated for eulachon (0.557 yr-1) was increased to 0.6 yr-1 to consider catch for the 1750 and 1900 models. Beattie (2001) uses the average of adult and juvenile herring Q/B ratios for forage fish (8.395 yr-1), and we use that value for both forage fish and eulachon in the 2000 model. The Q/B of 6.61 yr-1 calculated in Appendix B Table B2 for forage fish was used for both forage fish and eulachon in the 1900 and 1750 models. The diet of forage fish was obtained from Beattie (2001), and was used in all four models. This value was adapted for eulachon, reducing the proportion of euphausiids in their diet in order to balance the model. We also assume that they do not feed on detritus and that copepods are more important in their diet. Final diet matrix for forage fish and eulachon is provided in Appendix D Table D11. There was a small recreational fishery for capelin in the past, specifically for the Georgia Strait area and this is probably also true for the Hecate Strait (Vasconcellos and Pitcher 2002f). A (seine net) reduction fishery for sardine began in 1917 and caught 70 tonnes that year. The catch increased to Back to the Future on Canada’s West Coast, Page 11  80,558 tonnes in 1943, but was reduced to 444 tonnes in 1947 (Schweigert 1987). The latter was used for our 1950 forage fish group (0.006 tkm-2yr-1). However, at present no forage fish is caught except for eulachon, for which the total catch in British Columbia is approximately 366 tonnes (or 0.005 tkm-2yr-1) and we assume that approximately 3/5ths of that is taken from the Hecate Strait. First Nations people harvest eulachon with herring rakes, seine, dip and bag nets after which they dried or smoked them and extracted their oil (Irwin 1984). Vasconcellos and Pitcher (2002e) assumed a tentative catch of 3,000 tonnes per year for the early 1900s by assuming that catches were one order of magnitude higher than in the present time, and also suggested that the pre-contact (1750) catch was probably similar (0.043 tkm-2yr-1). Beattie (2001) obtained values on discards of forage fish by the groundfish trawl fisheries from DFO’s observer program database for 1997 (see Appendix A Table A2) and we split the discard into forage fish (0.04 kgkm-2yr-1) and eulachon (0.007 kgkm-2yr-1) using the 1/6th eulachon rule that we employ for diets (Vasconcellos and Pitcher 2002e). Eulachon is also discarded by the shrimp trawl fishery, and Hay et al. (1999) calculated that shrimp trawlers on the central coast discard approximately 90 tonnes (0.001 tkm-2yr-1) of eulachon each year. The discards of other forage fish species by the shrimp trawl fishery were not significant (Table 4 in Hay et al. 1999). 17-18) Juvenile and adult herring  Herring was the focus of a reduction fishery early in the 20th century and is important to First Nations people (Jones 2000; Beattie 2001). Herring was split into adult and juvenile compartments to reduce the effects of cannibalism in the model. The 2000 biomass of adult and juvenile herring was obtained from Beattie (2001) at 2.265 tkm-2. Biomass for the 1950 model is 0.748 tkm-2 based on DFO archival records. The biomass of juvenile and adult herring in the 1900 and 1750 models was estimated by assuming an ecotrophic efficiency of 95%. A negative biomass accumulation was accepted for 1950 adult herring of 50% per year, in light of the damaging reduction fishery that continued until the mid-1960s.  The 2000 and 1950 P/B ratios for juveniles (2.19 yr-1) and adults (0.683 yr-1) were obtained from Beattie (2001). Natural mortality is calculated in Appendix B Table B1 (adult = 0.792 yr-1 and juvenile 1.173 yr-1) were used for the 1900 and 1750 models. The P/B of adult herring was considered marginally higher than M due to First Nations catches in 1750 and a small fishery in 1900 – we assume that the P/B of adult herring is 0.8 yr-1 for both models. The 2000 Q/B ratios for juveniles (10.95 yr-1) and adults (5.84 yr-1) were obtained from Beattie (2001), and those calculated in Appendix B Table B2 (adult = 7.5 yr-1 and juvenile = 11.3 yr-1) were used for the 1900 and 1750 models. The diet of juvenile and adult herring was obtained from Beattie (2001) and used in all four models (Appendix D Table D12). Herring is caught as bycatch to the groundfish trawl fishery (0.002 tkm-2yr-1  – see Appendix A Table A2 obtained from Beattie 2001). Schweigert and Fort (1999) give catches of herring from the Queen Charlotte Sound, Prince Rupert and the Central Coast. We divide this catch into gillnet (64% or 0.12 tkm-2yr-1) and seine net (36% or tkm-2yr-1) catches based on data from DFO (Sweigert and Fort, 1999) (Table 7). The herring fishery in Prince Rupert (DFO 2001a) and on the Central Coast (DFO 2001b) started around the turn of the century, but only became large at the start of the dry salt fishery in the mid 1930s, while in the Queen Charlotte Islands catches were first reported in 1937 (DFO 2001c; Jones 2000). Thus, we estimate that the catch was well below the approximately 66,000 tonnes caught in all three areas combined from 1951-1960, and we assume that it was similar to the approximately 0.25 million pounds, or 0.002 tkm-2yr-1, caught by First Nations in pre-contact times (Carrothers 1941). Catches for the 1950 model were taken from DFO catch statistics (DFO 1995). Herring is caught and discarded by the groundfish trawl fishery in the 2000 model (0.003 tkm-2yr-1 – see Appendix A Table A2 obtained from Beattie, 2001). 19-20) Pacific ocean perch: juvenile and adult Pacific Ocean perch has been an important part of the groundfish fishery in British Columbia, and was targeted from the early 1960s by domestic and international fisheries (Beattie 2001). The Table 7:  Herring catch (tonnes) by region. Source: Sweigert and Fort. (1999). Catch Queen Charlotte Sound Prince Rupert Central Coast Total 1994/95 0 2,877 10,308 13,185 1995/96 0 4,178 5,209 9,387 1996/97 0 6,815 4,806 11,621 1997/98 2100 4,218 9,965 16,283 1998/99 3792 3,114 8,738 15,644 Average    13,224 Ecosystem Models of Northern BC, Past and Present, Page 12  2000 biomass of both juvenile (0.065 tkm-2yr-1) and adult Pacific Ocean perch (1.819 tkm-2yr-1) was obtained from Beattie (2001), while the 1750 and 1900 biomasses for adults and juveniles were estimated by assuming an ecotrophic efficiency of 95%. A negative biomass accumulation of approximately 18% (-0.3 tkm-2yr-1) was calculated for Pacific Ocean perch in the 2000 model, from the B1996/B0 values obtained from Walters and Bonfil (1999). The 1950 and 2000 P/B ratios for juveniles (0.672 yr-1) and adults (0.144 yr-1) were obtained from Beattie (2001), and the natural mortality calculated in Appendix B Table B1 was used as P/B estimates in 1900 and 1750 (0.23 yr-1 for adults and 0.34 yr-1 for juveniles). Lower P/B for juveniles in the 1900 and 1750 models are justified because, although few fisheries target them, many are killed as bycatch and by other fishery activities. The 1950 and 2000 Q/B ratios for juveniles (3.21 yr-1) and adults (2.14 yr-1) were obtained from Beattie (2001) and the ratios calculated in Appendix B Table B2 were used in the 1900 and 1750 models (4.08 yr-1 for adults and 6.12 yr-1 for juveniles). The diets of juvenile and adult Pacific Ocean perch were obtained from Beattie (2001) and used for all four models. Note that P/Q juveniles in the 1950 and 2000 models = 0.209; P/Q juveniles in the 1900 and 1750 models = 0.05. In future revisions of the model these might be maintained at the same level. Catches of Pacific Ocean perch by the groundfish trawl fishery (0.065 tkm-2yr-1 – see Appendix A Table A2) in the 2000 model were obtained from Beattie (2001). The 1950 catches for this group are based on red and rock cod, taken from DFO commercial catch statistics for 1951 (DFO 1995). Pacific Ocean perch was caught and discarded in the 1950 and 2000 model by the groundfish trawl fishery (0.002 tkm-2yr-1 – see Appendix A Table A2 obtained from Beattie (2001)). 21) Inshore rockfish Inshore rockfish include copper rockfish, quillback rockfish, tiger rockfish, China rockfish and yelloweye rockfish. The 1950 and 2000 biomass of inshore rockfish (0.1 tkm-2) was obtained from Beattie (2001), while those of the 1900 and 1750 models were calculated by assuming an ecotrophic efficiency of 95%. (Some argue that lower EEs might apply to high trophic level fish in the models of the past.)  The 1950 and 2000 P/B ratio for inshore rockfish (0.19 yr-1) was obtained from Beattie (2001), and the natural mortality (0.18 yr-1), calculated in Appendix B Table B1, was used as the P/B ratio for inshore rockfish in the 1900 and 1750 models. The 1950 and 2000 Q/B ratio for inshore rockfish (5.688 yr-1) was obtained from Beattie (2001), and the Q/B ratio (3.7 yr-1) calculated in Appendix B Table B2 was used in the 1900 and 1750 models. The diet of inshore rockfish was obtained from Beattie (2001), used in all four models and adapted for the new model groupings by assuming that 1/6th of the proportion of forage fish in their diet is obtained from eulachon (Vasconcellos and Pitcher 2002e). Adult herring was reduced as a diet component in the 1950 model to 0.050; the difference was transferred to commercial shrimp, infaunal carnivorous invertebrates and euphausiids. The 2000 catches of inshore rockfish include 0.3 kgkm-2yr-1 (Appendix A Table A2) taken by the groundfish trawl fishery, 0.003 tkm-2yr-1 caught by the groundfish hook and line fishery, 0.004 tkm-2yr-1 by the halibut hook and line fisheries (Beattie 2001) and 0.004 tkm-2yr-1 taken by the recreational fishery (adapted from Forrest 2002) to total 0.01 tkm-2yr-1. Catch records do not extend as far back as 1950 for rockfish groups, so commercial catch for that model was arbitrarily assumed to be one half of the present value, and recreational catch was assumed to be 9% of the current recreational value (after Forrest 2002) to total 0.0037 tkm-2yr-1. Inshore rockfish is caught and discarded by the groundfish trawl fishery (0.2 kgkm-2yr-1 – see Appendix A Table A2 obtained from Beattie (2001)). 22-23) Piscivorous rockfish: juvenile and adult Piscivorous rockfish include species that feed mainly on fish and large invertebrates: rougheye, shortraker, short and longspine thornyheads, black, blue, chillipepper and dusky rockfish. The 2000 biomasses of both juvenile (0.007 tkm-2) and adult piscivorous rockfish (0.654 tkm-2) were obtained from Beattie (2001), while those of the 1900 and 1750 models were estimated by assuming an ecotrophic efficiency of 95%. Biomass for the 1950 model for adult piscivorous rockfish (0.753 tkm-2) was calculated by Ecopath assuming an EE of 0.95. The 1950 biomass of juveniles (0.008 tkm-2) was arrived at by assuming the same ratio of juveniles to adults as in the 2000 model. A negative biomass accumulation of approximately 1% (0.007 tkm-2yr-1) was calculated for adult piscivorous rockfish in the 2000 model from the B1996/B0 values obtained from (Walters and Bonfil 1999). This value was removed from the 1950 model.  Back to the Future on Canada’s West Coast, Page 13  The 1950 and 2000 P/B ratios of both juvenile (0.261 yr-1) and adult piscivorous rockfish (0.037 yr-1) were obtained from Beattie (2001). The natural mortality estimated in Appendix B Table B1 for adult (0.296 yr-1) and juvenile (0.440 yr-1) piscivorous rockfish were much higher than those obtained from Beattie (2001), and gave very low biomass estimates for these species, so we use the P/B ratios obtained from Beattie (2001) for all four models. The 1950 and 2000 Q/B ratios for both juvenile (1.89 yr-1) and adult piscivorous rockfish (1.26 yr-1) were obtained from Beattie (2001) and were again much lower than those calculated in Appendix B Table B2. We used the estimates from Beattie (2001) for all four models. The diet of adult and juvenile piscivorous rockfish were obtained from Beattie (2001), used for all four models and adapted for the new model groupings by assuming that 1/6th of the proportion of forage fish in their diet is obtained from eulachon (Vasconcellos and Pitcher 2002e). In the 2000 model adult piscivorous rockfish was caught by the groundfish trawl fishery (0.02 tkm-2yr-1 – see Appendix A Table A2 obtained from Beattie (2001)) and the groundfish hook and line fishery (0.002 tkm-2yr-1 for rougheye rockfish obtained from Beattie (2001)). Forrest (2002) summarizes the recreational catch of rockfish from an unpublished DFO survey; this amount was evenly distributed between the two adult (piscivorous) rockfish groups in this model, inshore rockfish and piscivorous rockfish. In balancing the model, this quantity was reduced slightly to 0.002 tkm-2yr-1 in the present group. Total present-day catch for this group is therefore 0.028 tkm-2yr-1. Catch records do not extend as far back as 1950 for rockfish groups, so commercial catch for the 1950 model was arbitrarily assumed to be one half of the present value, and recreational catch was assumed to be 9% of the current recreational value (after Forrest (2002)) to total 0.011 tkm-2yr-1. Piscivorous rockfish was caught and discarded by the groundfish trawl fishery (0.3 kgkm-2yr-1 – see Appendix A Table A2 obtained from Beattie (2001)) in the 2000 model. 24-25) Planktivorous rockfish: juvenile and adult Planktivorous rockfish feed primarily on zooplankton and are mainly pelagic (Beattie 2001), they include: yellowmouth, red-stripe, widow, yellowtail, darkblotch, canary, splitnose, sharpchin, Puget sound, bocaccio and shortbelly rockfish. The 2000 biomasses of juvenile (0.136 tkm-2) and adult planktivorous rockfish (1.2 tkm-2) were obtained from Beattie (2001), while those of the 1900 and 1750 models were estimated by assuming an ecotrophic efficiency of 95%. The 1950 estimate for adult planktivorous rockfish (1.664 tkm-2) was also arrived at by assuming an ecotrophic efficiency of 95%. This value falls approximately halfway between the 1900 and 2000 estimates. The biomass estimate for juvenile planktivorous rockfish (0.189 tkm-2) was arrived at by assuming the same ratio of adults to juveniles as in the 2000 model. A negative biomass accumulation of approximately 8% (-0.095 tkm-2yr-1) was calculated for adult planktivorous rockfish from the B1996/B0 values obtained from Walters and Bonfil (1999). This value was omitted from the 1950 model. The 1950 and 2000 P/B ratios of both juvenile (0.261 yr-1) and adult planktivorous rockfish (0.068 yr-1) were obtained from Beattie (2001) and these values were much lower than the values calculated in Appendix B Table B1 for natural mortality, so we used the values obtained from Beattie (2001) for all four models. The 1950 and 2000 Q/B ratios for both juvenile (3.21 yr-1) and adult planktivorous rockfish (2.14 yr-1) were obtained from Beattie (2001) and these values were much lower than the values calculated in Appendix B Table B2, so we used the values obtained from Beattie (2001) for all four models. The diets of adult and juvenile planktivorous rockfish were obtained from Beattie (2001) and adapted for the new model groupings by assuming that 1/6th of the proportion of forage fish in their diet is obtained from eulachon (Vasconcellos and Pitcher 2002e). These estimates were used for all four models. In the 2000 model, the groundfish trawl fishery caught 0.076 tkm-2yr-1 of adult planktivorous rockfish (Appendix A Table A2 obtained from Beattie (2001)). There is no recreational catch for planktivorous rockfish, since they do not respond to baited hooks. Total present catch for the adult group is then 0.076 tkm-2yr-1. Catch records do not extend as far back as 1950 for rockfish groups, so commercial catch for the 1950 model was arbitrarily assumed to be one half of the present value, and recreational catch was assumed to be 9% of the current recreational value (after Forrest (2002)) to total 0.036 tkm-2yr-1. Planktivorous rockfish was caught and discarded in the 1950 and 2000 model by the groundfish trawl fishery (0.005 tkm-2yr-1 – see Appendix A Table A2 obtained from Beattie (2001)). Large amounts of rockfish are also caught as bycatch to the salmon gillnet fishery according to Beattie (pers. comm.), and he assumes a value of 0.001 tkm-2yr-1  for discards from this fishery in the 2000 model. Ecosystem Models of Northern BC, Past and Present, Page 14  26-27) Juvenile and adult turbot (=arrowtooth flounder) The turbot, or arrowtooth flounder, has a large biomass in this system (Beattie 2001). The 1950 and 2000 biomass estimates of both juvenile (0.218 tkm-2) and adult turbot (1.5 tkm-2) were obtained from Beattie (2001) while their biomasses were estimated by assuming an ecotrophic efficiency of 95% in the 1900 and 1750 models. Vasconcellos and Fargo (2002) suggest that the unfished equilibrium biomass of turbot was estimated at 56,000 tonnes which is similar to the biomass estimated for adult turbot in 1900, however our estimates of biomass in 1750 were three times as large. The P/B ratios of both juvenile (0.33 yr-1) and adult turbot (0.22 yr-1) were obtained from Beattie (2001) and used in all four models. The Q/B ratios for both juvenile (2.172 yr-1) and adult turbot (1.983 yr-1) were obtained from Beattie (2001) and used in all four models. The diets of juvenile and adult turbot were obtained from Beattie (2001) and adapted for the new model groupings by assuming that 1/6th of the proportion of forage fish in their diet is obtained from eulachon (Vasconcellos and Pitcher 2002e). The 1950 diet for juvenile and adult turbot was assumed to be similar to 2000. In 1750 (and 1900) no discards were available, and the discards consumed by juvenile turbot in the 2000 model were added to epifaunal invertebrates, while the discards consumed by adult turbot in the 2000 model were added to shallow water benthic fish. In the 2000 model, adult turbot is caught by the groundfish trawlers (0.02 tkm-2yr-1 – see Appendix A Table A2 obtained from Beattie (2001)). DFO commercial catch statistics from 1951 (DFO 1995) were accepted for the 1950 adult turbot group (0.00288 tkm-2yr-1), all caught by groundfish trawlers. Adult turbot is caught and discarded by the groundfish trawl fishery in the 2000 model (0.03 tkm-2yr-1 – see Appendix A Table A2 obtained from Beattie (2001)). Turbot is also caught as bycatch (0.7 kgkm-2yr-1, see Appendix A Table A1) to the shrimp trawl fishery (Hay et al. 1999) in the 2000 model. This bycatch was removed entirely from the 1950 model, since the total catch was an order of magnitude less during that period than in the present day. 28-29) Juvenile and adult flatfish Information on flatfish is not readily available except for those species that are taken by the groundfish trawl fishery: rock sole, English sole and dover sole (Beattie 2001). Other species that are also included in this compartment, but for which very little information is available, include: butter sole, petral sole, rex sole, slender sole, flathead sole, starry flounder and Pacific sanddab. The 2000 biomass estimates of both juvenile (0.259 tkm-2) and adult flatfish (0.392 tkm-2) were obtained from Beattie (2001). The 1950 biomass estimate for adult flatfish (0.221 tkm-2) was obtained by assuming an EE of 0.95. Juvenile biomass (0.150 tkm-2) was calculated by assuming the same proportion of juvenile to adult as in the 2000 model. Biomass for the 1900 and 1750 models were estimated by assuming an ecotrophic efficiency of 95%. Vasconcellos and Fargo (2002) suggest that the unfished equilibrium biomasses of rock sole, English sole and Dover sole were 8,500 tonnes, 5,200 tonnes and 14,000 tonnes respectively, which gives B0 of approximately 0.4 tkm-2. This is similar to the biomass estimated for adult flatfish in 1900, however, the precontact biomass was more than four times that amount. The 1950 and 2000 P/B ratio for juvenile flatfish (1.9 yr-1) was based on a reported daily growth rate of 0.53% (Smith et al. 1995), while that of adult flatfish (0.9 yr-1) was obtained from (Beattie 2001) (Table A1.26). The natural mortality of flatfish was estimated in Appendix B Table B1 and was assumed to be equal to the P/B ratios (0.38 yr-1 = juvenile and 0.26 yr-1 = adult) for the 1900 and 1750 models. The 1950 and 2000 Q/B ratios for both juvenile (6.02 yr-1) and adult flatfish (4.3 yr-1) were obtained from the unbalanced model of Beattie (2001), and were similar to those estimated in Appendix B Table B2 – 4.2 yr-1 for adults and 6.3 yr-1 for juveniles, which were used for the 1900 and 1750 models. The diets of juvenile and adult flatfish were obtained from Beattie (2001), adapted for the new model groupings by assuming that 1/6th of the proportion of forage fish in their diet is obtained from eulachon (Vasconcellos and Pitcher 2002e). The proportion of the diet attributed to benthic invertebrates was divided into infaunal carnivorous invertebrates and infaunal invertebrate detritivores. These estimates were used for all four models. In the 2000 model, adult flatfish is caught by the groundfish trawl fishery (0.05 tkm-2yr-1– see Appendix A Table A2 obtained from Beattie (2001)). Adult flatfish catch (0.0392 tkm-2yr-1) for the 1950 model was taken from 1951 DFO catch statistics (DFO 1995). Adult flatfish is caught as bycatch (0.002 tkm-2yr-1, see Appendix A Table A1) to the shrimp trawl fishery in the 2000 model (Hay et al. 1999). Back to the Future on Canada’s West Coast, Page 15  30-31) Juvenile and adult halibut Beattie (2001) assumes that the biomass of both juvenile and adult (0.6 tkm-2) halibut is the same, and we use his estimates in the 2000 model. The 1950 model reduces this estimate to 0.429 tkm-2, according to the 1950 biomass value provided by Quinn (1985). Vasconcellos and Pitcher (2002g) suggest that the biomass of halibut in the early 1900s might be higher than at present although the recovery of the stock supports the hypothesis of the same biomass in the past as at the present time. Schreiber (2002) suggests that the biomass around the turn of the century was lower than in the 1700s, so we use the 2000 biomass estimate for adult halibut obtained from Beattie (2001) for the 1900 model, and assume that the biomass in 1750 was much higher (1.0 tkm-2). We estimated the biomass of juvenile halibut for both the 1750 and 1900 models by assuming an ecotrophic efficiency of 95%. The 1950 and 2000 P/B ratios for both juvenile (0.6 yr-1) and adult halibut (0.4 yr-1) were obtained from Table A1.26 in Beattie (2001). The natural mortality estimates of adult (0.064 yr-1) and juvenile (0.096 yr-1) halibut calculated in Appendix B Table B1 were added to the fishing mortalities (1900F = 0.02 yr-1 and 1750F = 0.003 yr-1) to calculate the P/B ratios for adults in 1900 and 1750 as 0.084 yr-1 and 0.067 yr-1 respectively, and for juveniles as 0.116 yr-1 and 0.099 yr-1 respectively. The 1950 and 2000 Q/B ratios for both juvenile (1.1 yr-1) and adult halibut (1.5 yr-1) were obtained from the unbalanced model of Beattie (2001), while those calculated in Appendix B Table B2 were used for the 1900 and 1750 models (adult = 1.7 yr-1 and juvenile = 2.5 yr-1). The diets of juvenile and adult halibut were obtained from Beattie (2001) and adapted for the new model groupings by assuming that 1/6th of the proportion of forage fish in their diet is obtained from eulachon (Vasconcellos and Pitcher 2002e).  Halibut is caught in the 2000 model by the groundfish trawl fishery (0.05 kgkm-2yr-1 each for adult and juveniles – see Appendix A Table A2 obtained from Beattie (2001)) and the hook and line fishery (0.028 tkm-2yr-1, Beattie (2001)). A small recreational catch of 0.014 tkm-2yr-1 is based on an unpublished survey by the DFO, summarized in Forrest (2002). Commercial catch of adult halibut for the 1950 model (0.097 tkm-2yr-1 groundfish trawl, 0.001 tkm-2yr-1 halibut hook and line) was taken from DFO catch statistics (DFO 1995). Recreational catch in 1950 was assumed to be 9% of the present day recreational catch according to Forrest (2002). Total catch was therefore 0.099 tkm-2yr-1 in 1950. Commercial fishing for Pacific halibut began in the 1880s and by 1909 fishermen already noticed that most of the formerly productive inshore areas had been depleted, and they began actively searching for previously unfished offshore grounds (Schreiber 2002). Rathbun (1990) gives catches of halibut in British Columbia (principally the Hecate Strait) in the late 1800s (Table 8), and we assume that 90% of his estimate (or 0.015 tkm-2yr-1) comes from our area and it is divided between adult and juvenile halibut (0.008 tkm-2yr-1 each). It is estimated that First Nations caught as much as 1.4 thousand tonnes (or 0.019 tkm-2yr-1) of halibut per year prior to the commercial fisheries (1750 model), and after 1888 they consumed over 270 tonnes annually (Carrothers 1941). All catches of halibut were split between adult and juveniles in the ratio of 1:1 (Pitcher, pers. comm.), thus the First Nations catch of juvenile and adult halibut in 1750 was approximately 0.009 tkm-2yr-1 each, while in the 1900 model it was around 0.001 tkm-2yr-1 . Halibut is caught and discarded (Beattie 2001) by the groundfish trawl fishery (0.0026 tkm-2yr-1 each for adult and juveniles (Pitcher, pers. comm.) (see Appendix A Table A2). This value was used in the 1950 and 2000 models. 32-33) Juvenile and adult Pacific cod The 2000 biomass of adult Pacific cod was estimated by Walters and Bonfil (1999) as 0.163 tkm-2 and it was assumed that the biomass of juveniles was approximately 36% of the total biomass (0.089 tkm-2). Biomass in the 1950 model for adult Pacific cod (0.086 tkm-2) was taken from a DFO stock assessment report representing all of British Columbia. The 1950 juvenile biomass (0.047 tkm-2) maintains the same ratio of adult to juvenile as in 2000. The biomass of juvenile and adult Pacific cod were estimated for both the 1900 and 1750 models by assuming an ecotrophic efficiency of 95%. The 1950 and 2000 P/B ratios for both juvenile (1.98 yr-1) and adult Pacific cod (1.32 yr-1) were obtained from Beattie (2001) (Table A1.26), while the natural mortality estimates from Appendix B Table B1 (0.26 yr-1 for juveniles and 0.17  yr-1 for Table 8:  Catches of halibut in Hecate Strait. Source: Rathbun, 1990.  Year Catch (pounds) Catch (tonnes) 1890 1,376,800 625 1891 2,124,500 964 1892 2,768,000 1,256 1895 4,251,000 1,928 Average 2,630,075 1,193 Ecosystem Models of Northern BC, Past and Present, Page 16  adults) were used as P/B ratios in the 1900 and 1750 models. The 1950 and 2000 Q/B ratios for both juvenile (7.5 yr-1) and adult Pacific cod (4.0 yr-1) were obtained from the unbalanced model of Beattie (2001) while the Q/B ratios estimated from Appendix B Table B2 (3.4 yr-1 for juveniles and 2.3 yr-1 for adults) were used in the 1900 and 1750 models. The diets of juvenile and adult Pacific cod were obtained from Beattie (2001) and adapted for the new model groupings by assuming that 1/6th of the proportion of forage fish in their diet is obtained from eulachon (Vasconcellos and Pitcher 2002e) and the proportion of the diet attributed to benthic invertebrates was divided into infaunal carnivorous invertebrates and infaunal invertebrate detritivores. These estimates were used for all four models.  First Nations people caught cod by using a lure and spear (Irwin 1984) and as it is thought to be a relatively short lived, high turnover species (Sinclair 2002) we assume a catch of around 0.001 tkm-2yr-1  for this species by First Nations in both the 1750 and 1900 models. In the 2000 model, adult Pacific cod is caught by the groundfish trawlers (0.02 tkm-2yr-1  – see Appendix A Table A2 obtained from Beattie 2001). In the 1950 model, catches for adult Pacific cod (0.052 tkm-2yr-1) are taken from DFO catch statistics (DFO 1995) for seine nets (64.1%), groundfish trawl (35.8%) and longline (0.03%). Adult Pacific cod is caught and discarded (Beattie 2001) by the groundfish trawl fishery (0.002 tkm-2yr-1  - see Appendix A Table A2) in the 1950 and 2000 models. 34-35) Juvenile and adult sablefish  Sablefish is also known as black cod (Beattie 2001). The 2000 biomass estimates of both juvenile (0.1 tkm-2) and adult (0.3 tkm-2) sablefish were obtained from Beattie (2001). Official DFO stock assessment reports indicate that there was approximately twice as much adult sablefish in the early 1960s as in the present day. Multiplying the present day estimate by two provided a rough estimate of the 1950 adult biomass (0.6 tkm2). The same ratio was maintained between juvenile and adult biomass as in the present day model to provide a juvenile biomass estimate of 0.238 tkm-2. Biomasses in the 1900 and 1750 models were estimated assuming an ecotrophic efficiency of 95%. The 1950 and 2000 P/B ratios for both juvenile (0.6 yr-1) and adult sablefish (0.3 yr-1) were obtained from Beattie (2001) (Table A1.26), while the natural mortality estimates from Appendix B Table B1 (0.27 yr-1 for juveniles and 0.18 yr-1 for adults) were used for P/B ratios in the 1900 and 1750 models. The Q/B ratios for both juvenile (7.0 yr-1) and adult sablefish (3.7 yr-1) were obtained from Beattie (2001) and used for all four models. The diets of juvenile and adult sablefish were obtained from (Beattie 2001) and adapted for the new model groupings by assuming that 1/6th of the proportion of forage fish in their diet is obtained from eulachon (Vasconcellos and Pitcher 2002e). These estimates were used for all four models. In the 2000 model, adult sablefish was caught by the groundfish trawlers (0.6 kgkm-2yr-1 – see Appendix A Table A2 obtained from Beattie 2001) and the sablefish trap fishery (0.06 tkm-2yr-1 - obtained from Beattie (2001) and DFO (1999a)). Total catch for adult sablefish was 0.00612 tkm-2yr-1 in 1951 according to DFO catch statistics (DFO 1995), divided into 63% longline and 37% groundfish trawl. Adult sablefish was caught and discarded (Beattie 2001) by the groundfish trawl fishery in the 1950 and 2000 models (0.003 tkm-2yr-1 - see Appendix A Table A2). 36-37) Juvenile and adult lingcod The 2000 biomass estimates of both juvenile (0.031 tkm-2) and adult (0.034 tkm-2) lingcod were obtained from Martell (1999) as cited in Beattie (2001). The 1950 estimate of adult biomass is 0.085 tkm-2 (adapted from Martell (1999)). Juvenile 1950 biomass was estimated by assuming the same ratio of adult to juvenile biomass as in 2000: the estimate is 0.078 tkm-2. Biomass was estimated by Ecopath for the 1900 and 1750 models by assuming an ecotrophic efficiency of 95 The 1950 and 2000 P/B ratio for adult lingcod (0.8 yr-1) was obtained from Beattie (2001) (Table A1.26), and that of juvenile lingcod (1.2 yr-1) was assumed to be 1.5 times that of adults (see Beattie (2001); an unbalanced model). The natural mortalities estimated in Appendix B Table B1 for adult and juvenile lingcod (0.26 yr-1 and 0.39 yr-1 respectively) were used as P/B ratios in the 1900 and 1750s models. The 1950 and 2000 Q/B ratios for both juvenile (3.3 yr-1) and adult lingcod (3.3 yr-1) were obtained from Beattie (2001), while those calculated in Appendix B Table B2 (3.9 yr-1 for juveniles and 2.8 yr-1 for adults) were used in the 1900 and 1750 models. The diet of adult lingcod was obtained from Beattie (2001) and was adapted for the new model groupings by assuming that 1/6th of the proportion of forage fish in their diet is obtained from eulachon (Vasconcellos and Pitcher 2002e). Back to the Future on Canada’s West Coast, Page 17  The diet of juvenile lingcod was adapted from the text of Cass et al. (1990), who suggested that juvenile lingcod feed on herring, forage fish, juvenile flatfish and Pacific cod (all 20%), shrimp and invertebrates (10% each), which were then adapted to include eulachon and all three of the invertebrate groups. These estimates were used for all models except 1950. In the 1950 model herring was reduced as a diet component to 0.159, to reduce predation pressure on that group. The difference was divided among juvenile lingcod, juvenile Pacific cod and juvenile planktivorous rockfish. In the 2000 model, adult lingcod is caught with groundfish trawls (0.007 tkm-2yr-1– see Appendix A Table A2 obtained from Beattie (2001)) and recreational fishermen catch both adult and juvenile lingcod. Cass, Beamish et al. (1990) suggest that currently, approximately 80 tonnes of lingcod is caught by scuba and 125 tonnes by recreational line fishermen, and we assume that the scuba catches (0.001 tkm-2yr-1) are mostly adults and that the line fishery (0.002 tkm-2yr-1) catch mostly juveniles, as Cass, Beamish et al. (1990) suggested that the recreational line fishery catch smaller sizes. In the 1950 model, groundfish trawl, groundfish hook and line and recreational fisheries together catch 0.05 tkm-2yr-1of adult lingcod. Data for 1950 was adapted from the historical estimates of Cass, Beamish et al., (1990). Lingcod was caught by First Nations people with wooden gorges, but was of minor imporance (Vasconcellos and Pitcher 2002h), and we assume a very small catch of 0.5 kgkm-2yr-1 for the 1750 model. Cass, Beamish et al. (1990) give catches for the whole of British Columbia around 1900-1905, and we use 50% of the 370 tonnes (0.003 tkm-2yr-1) as the catch in the 1900 model. Adult lingcod is caught and discarded (Beattie 2001) by groundfish trawl fishermen in the 1950 and 2000 models (0.001 tkm-2yr-1 - see Appendix A Table A2). 38) Shallow-water benthic fish This group includes the sculpins, blennies, poachers, gobies and the greenlings, especially rock greenling and other nearshore fishes such as eelpouts, northern clingfish, red irish lords, cabezon, cutthroat trout and white sturgeon. The 1950 and 2000 biomass estimate of shallow water benthic fish (1.5 tkm-2) was obtained from Beattie (2001), while the 1900 and 1750 models were estimated by assuming an ecotrophic efficiency of 95%.  The 2000 P/B ratio for shallow water benthic fish (0.8 yr-1) was obtained from Beattie (2001) (Table A1.26), while the natural mortality of 0.27  yr-1 calculated in Appendix B Table B1 was used as the P/B ratio of shallow water benthic fish in the 1900 and 1750 models. The 1950 and 2000 Q/B ratio for shallow water benthic fish (5.3 yr-1) was obtained from Beattie (2001), while the Q/B ratio (2.1 yr-1) calculated in Appendix B Table B2 was used in the 1900 and 1750 models. The diet of shallow water benthic fish was obtained from Beattie (2001) and was adapted for the new model groupings by assuming that 1/6th of the proportion of forage fish in their diet is obtained from eulachon (Vasconcellos and Pitcher 2002e) and the proportion of the diet attributed to benthic invertebrates was divided into infaunal carnivorous invertebrates and infaunal invertebrate detritivores. This estimate was used for all four models A small amount of shallow water benthic fish is caught with groundfish trawlers in the 2000 model (0.001 kgkm-2yr-1 – see Appendix A Table A2 obtained from Beattie (2001)). In the 2000 model, a small amount of shallow water benthic fish is caught and discarded (Beattie 2001) by the groundfish trawl fishery (0.04 kgkm-2yr-1 - see Appendix A Table A2) and the shrimp fishery (0.001 kgkm-2yr-1 - see Appendix A Table A1 obtained from Hay et al. (1999)). 39) Skates This compartment consists mostly of skates, although the few stingrays and sharks that are present in the system are also included. The skates include the big skate, longnose skate, starry skate, black skate and the deep-sea skate (Beattie 2001), while the sharks include the tope shark, great white shark, broadnose sevengill shark,  bluntnose sixgill shark, blue shark and basking shark and the stingrays include the diamond stingray and Pelagic stingray (Froese and Pauly, 2002). The 1950 and 2000 biomass estimate of this compartment (0.36 tkm-2) was obtained from Beattie (2001), while for the 1900 and 1750 models, the biomasses of skates were estimated using ecotrophic efficiencies of 95%.  The 1950 and 2000 P/B ratio for skates (0.31 yr-1) was obtained from Beattie (2001) (Table A1.26), and the natural mortality (0.15 yr-1) estimated in Appendix B Table B1 was used for the 1900 and 1750 models. The 1950 and 2000 Q/B ratio for skates (1.24 yr-1) was obtained from Beattie (2001), and the ratio (1.2 yr-1) calculated in Appendix B Table B2 was used for the 1900 and 1750 models. The diet of skates was obtained from Beattie (2001) and was adapted for the new model groupings by assuming that 1/6th of the proportion of forage fish in their diet is obtained Ecosystem Models of Northern BC, Past and Present, Page 18  from eulachon (Vasconcellos and Pitcher 2002e) and the proportion of the diet attributed to benthic invertebrates was divided into infaunal carnivorous invertebrates and infaunal invertebrate detritivores. This estimate was used for all four models. Skates are caught with groundfish trawlers in the 2000 model (0.02 tkm-2yr-1 – see Appendix A Table A2 obtained from Beattie (2001)). A very small catch of skate was included in the 1950 model, 0.0895 kgkm-2yr-1 (DFO 1995). Only half this amount was indicated by the DFO catch records for groundfish trawl in 1951, but an equal value was arbitrarily assigned to longline, in order to account for some level of bycatch. Skates are caught and discarded Beattie (2001) by the groundfish trawl fishery (0.007 tkm-2yr-1 - see Appendix A Table A2) and the shrimp fishery (0.0005 tkm-2yr-1 - see Appendix A Table A1 obtained from Hay et al. (1999)) in the 1950 and 2000 models. 40-41) Large and small crabs Crabs are divided into large crabs, with a carapace length of more than 120 mm, and small crabs – carapace length less than 120 mm. The large crabs include mostly Dungeness crab, but also the red rock crab, tanner crab and king crab, while the small crabs include the juveniles (< 120 mm carapace length) and other small crabs such as kelp crab (Beattie 2001). The biomasses of both large and small crabs were estimated by setting their ecotrophic efficiencies at 95% in all four models.  The P/B ratios of large (1.5 yr-1) and small (3.5 yr-1) crabs were obtained from Beattie (2001) (Table A1.26) and used in all four models. The Q/B ratios of both large and small crabs were estimated by setting their P/Q ratios at 0.3 and 0.25 respectively for all four models. The diets of large and small crab were obtained from Beattie (2001) and the proportion of the diet attributed to benthic invertebrates was divided into infaunal carnivorous invertebrates and infaunal invertebrate detritivores.  In the 2000 model, a very small amount of large crabs are caught with groundfish trawlers (0.003 kgkm-2yr-1 – see Appendix A Table A2 obtained from Beattie (2001)), while the main fishery for large crabs is the crab trap fishery, which catches approximately 0.053 tkm-2yr-1 (Beattie 2001). Forrest (2002) summarizes the recreational catch (0.0016 tkm-2yr-1) of large crabs from an unpublished DFO survey. Total catch in 1951 was then 0.055 tkm-2yr-1. The 1950 model applies 1951 DFO catch statistics (DFO 1995) for Hecate Strait and Dixon Entrance. Historical records indicate that only 0.0053 tkm-2yr-1 of large crabs were caught commercially during that time, which is an order of magnitude less than the present-day catch. About 91% was caught by trap, and the remainder by groundfish trawl. Forrest (2002) estimates the recreational catch as 9% of the present-day value. Total catch in 1951 was then 0.0054 tkm-2yr-1. Both large (0.2 kgkm-2yr-1) and small (0.04 kgkm-2yr-1) crabs are caught and discarded (Beattie 2001) with groundfish trawl fishery (Appendix A Table A1) in the 2000 model. 42) Commercial shrimp This group includes the penaeid prawn and shrimp: smooth shrimp, spiny shrimp, pink shrimp, coonstripe, humpback shrimp, sidestripe and prawn (Beattie 2001). The 2000 biomass estimate of this compartment (0.06 tkm-2) was obtained from (Beattie 2001), and the biomass of commercial shrimp in the 1950, 1900 and 1750 models were estimated assuming an ecotrophic efficiency of 95%.  The 1950 and 2000 P/B ratio for shrimp (11.5 yr-1) was obtained from Beattie (2001), Table A1.26, and for the 1900 and 1750 models it was assumed that the P/B was approximately 50% of the 2000 P/B as there was no fishing mortality. The Q/B ratio of shrimp was calculated by assuming a P/Q ratio of 25% in all four models. The diet of shrimp was obtained from Beattie (2001) and used in all four models. In the 2000 model, a very small amount of shrimp is caught with groundfish trawls (0.001 kgkm-2yr-1 – see Appendix A Table A2 obtained from Beattie (2001)), while the shrimp trawl fishery catches 0.05 tkm-2yr-1 (Beattie 2001). The prawn trap fishery in the 2000 model harvests approximately 0.006 tkm-2yr-1 (Beattie 2001). Forrest (2002) cites an unpublished DFO survey that identifies a small recreational catch of commercial shrimp (0.4 kgkm-2yr-1). The 1950 model assumes a catch of 0.612 kgkm-2yr-1, caught entirely by shrimp trawl, after 1951 DFO catch statistics (DFO 1995). A very small amount of shrimp (0.004 kgkm-2yr-1 – see Appendix A Table A2) is caught and discarded (Beattie 2001) by the groundfish trawl fishery in the 2000 model. 43-45) Epifaunal, infaunal carnivorous and detritivorous invertebrates Epifaunal invertebrates include echinoderms, molluscs, cnidarians and amphipods, while infaunal carnivorous invertebrates include mostly Back to the Future on Canada’s West Coast, Page 19  polychaetes, and infaunal invertebrate detritivores include the nemertea, gastropoda, pelecypoda, scaphopoda, ostracoda, cumacea, isopoda, amphipoda, decapoda, sipunculida, ophiuroidea, echinoidea, and holothuroidea that feed on detritus. The biomass of epifaunal invertebrates was estimated in all four models by assuming an ecotrophic efficiency of 95%, while that of the polychaetes were extracted from the benthic infaunal biomass given by Beattie (2001) to give biomass estimates of 13.25 tkm-2 and 34.305 tkm-2 each for carnivorous and detritivorous infauna in the 1950 and 2000 models. The biomasses of both infaunal compartments were estimated in the 1900 and 1750 models by assuming ecotrophic efficiencies of 95% for each.  The P/B ratios of epibenthic invertebrates (1.4 yr-1) and detritivorous infauna (1.3 yr-1) were obtained from Beattie (2001), while that of carnivorous invertebrates (2.0 yr-1) was obtained from Jarre-Teichmann and Guénette (1996), and these ratios were used for all four models. The Q/B ratios of all three invertebrate groups were estimated by assuming a P/Q ratio of 0.09 (Beattie 2001) in all four models. The diets of epifaunal invertebrates and detritivorous infauna were obtained from Beattie (2001), and it was assumed that carnivorous infauna feed mostly on detritus, but also on detritivorous infauna. These estimates were used in all four models In the 2000 model, a very small amount of epifaunal invertebrates are caught by groundfish trawlers (0.08 kgkm-2yr-1 – see Appendix A Table A2, Beattie 2001), but the largest fisheries for epifaunal invertebrates (0.078 tkm-2yr-1) are for sea urchins, Stronglyocentrotus spp., and sea cucumbers, Parastichopus californicus (Beattie 2001). Forrest (2002) cites an unpublished DFO survey that identifies a recreational catch of 0.00022 t/km2/yr, composed of clams, oysters and other shellfish. DFO archives report that the commercial harvest of epifaunal invertebrates in 1950 was approximately 37.7% of present day. The 1950 estimate was therefore taken as 0.0294 tkm-2yr-1; this amount accounts for butter clams primarily. Recreational catch in 1950 was assumed to be 9% of the present-day value after Forrest (2002). Total catch used in the 1950 model was 0.029 tkm-2yr-1. Vasconcellos and Pitcher (2002i) suggest that aboriginal fisheries for invertebrates always existed, but with no estimate of catch we assume a very small catch of 0.5 kgkm-2yr-1 each for epifaunal invertebrates and infaunal detritivores in the 1750 model and an even smaller catch of 0.1 kgkm-2yr-1 each in the 1900 model, as there was a large reduction in First Nations people from pre-contact. Epifaunal invertebrates (0.002 tkm-2yr-1) and detriti-vorous infaunal invertebrates (0.003 kgkm-2yr-1 – see Appendix A Table A2) are caught and discarded (Beattie 2001) by the groundfish trawl fishery in the 1950 and 2000 models. 46) Carnivorous jellyfish The 1950 and 2000 biomass estimate of jellyfish (3.0 tkm-2) was obtained from Beattie (2001), while in the 1900 and 1750 models it was estimated by assuming an ecotrophic efficiency of 95%. The P/B ratio for jellyfish (18 yr-1) was obtained from Beattie (2001) (Table A1.26) and used in all four models. The Q/B ratio for jellyfish (60 yr-1) was obtained from Beattie (2001) and used in all four models. Beattie (2001) suggests that the diet of jellies consists primarily of small zooplankton, zooplankton eggs and other jellies. The 10% attributed to carnivorous jellies in Beattie (2001) is split into 5% jellies and 5% copepods. This estimate was used for all four models. Jellyfish (0.03 kgkm-2yr-1: see Appendix A Table A2) are caught and discarded by the groundfish trawl fishery and large amounts of jellyfish are caught in salmon gillnets during the warmest months (Beattie 2001). No data are available, but a catch of 0.0001 tkm-2yr-1 was assumed in the 1950 and 2000 models. 47-48) Euphausiids and copepods Euphausiids in the Hecate Strait consist of three species (Thysanoessa spinifera, T. longipes and Euphausia pacifica) that account for 90% of biomass (Beattie 2001). Copepods include Pseudocalanus spp., Oithona spp. and Acartia spp. (Beattie 2001). The biomass estimates of euphausiids (8.70 tkm-2) and copepods (4.7 tkm-2) in the 1950 and 2000 models were obtained from Beattie (2001), while their biomasses were estimated for the 1900 and 1750 models by assuming an ecotrophic efficiency of 95% each. The P/B ratios for euphausiids (6.1 yr-1) and copepods (27 yr-1) were obtained from Beattie (2001) (Table A1.26) and used in all four models. The 1950 and 2000 Q/B ratio for euphausiids (24.8 yr-1) was obtained from Beattie (2001) and that of copepods (99 yr-1) was calculated by assuming a P/Q ratio of 30%. These Q/B ratios were also used for the 1900 and 1750 models. The diets of both euphausiids and copepods were obtained from (Beattie 2001) and used in all four models. Ecosystem Models of Northern BC, Past and Present, Page 20  49) Corals and sponges Sponge biomass is estimated to be approximately 300 tkm-2 in areas of sponge reef that have not been affected by bottom trawling and other forms of seafloor impacts (Conway 2002). The habitat in the study area that is suitable to these organisms is estimated at approximately 700 km2 according to Conway (2002). It is estimated that 30-50 % of the total sponge reef area has been affected by trawling and other forms of seafloor impacts through fishing (Conway 2002). The areas covered by the sponge reefs or sponge mud mounds is about 700 km2 (Conway 2002) and if a 30 – 50 % reduction in sponge populations has occurred since the initiation of bottom dragging then the biomass value we would assign to all the sponges on the sponge reefs in total would be on the order of 150 – 210 tkm-2. Thus the overall biomass of corals and sponges for the Hecate Strait is 1.9 tkm-2 in the 2000 model and prior to trawling it was probably closer to 3.2 tkm-2 (1900 and 1750 model). The 1950 model uses the mean value between the 1900 and 2000 estimates, which is 2.6 t tkm-2. Conway (2002) suggested an annual P/B ratio of 0.01 yr-1, which we used for all four models. A Q/B ratio of 2.0 yr-1 used in all four models, although no good information is available on this. We assume that the corals and sponges filter detritus from the water column. 50) Macrophytes This compartment consists of bull kelp and giant kelp; also seaweeds and sea grasses. The 1950 and 2000 biomasses of macrophytes (5.3 tkm-2) were obtained from Beattie (2001) and Sloan (2002) and suggest that the 2000 biomass is probably the same as in the 1900s, but higher in the 1750s when sea otters were abundant. It was thus assumed that the 1750s biomass (10.6 tkm-2) is double that of the 1900 and 2000 models. The P/B ratio for macrophytes (5.3 yr-1) was obtained from Beattie (2001) (Table A1.26) and used in all four models. 51) Phytoplankton The biomass of phytoplankton (15.4 tkm-2) was obtained from Beattie (2001) and it was assumed that the biomass was similar for all four time-periods. The P/B ratio for phytoplankton (179 yr-1) was obtained from Beattie (2001) (Table A1.26) and it was assumed that primary production was similar for all four time periods. 52) Discards Fishery discards were captured in this compartment to link birds and other discard feeders to discards. The 1950 and 2000 discard pool biomass (0.07 tkm-2) was obtained from Beattie (2001) and it was assumed that nothing was discarded in 1900 or 1750.  53) Detritus A single detritus pool (10 tkm-2) was obtained from Beattie (2001) and assumed to be similar for all four models. In future improvements to the model, two detritus pools might be added, one for dissolved and one for particulate matter.     BALANCING THE MODELS  Adult herring and copepods were reduced in the diet of Mysticetae in order to balance those two groups. Accordingly, euphausids were increased in the diet of Mysticetae, as they were already a major component (84% according to Beattie, 2001).  The proportion of seals and sea lions in the diet of toothed whales was reduced to balance the 2000 model, and transient salmon was increased. Inshore rockfish was reduced as a diet component of Odontocetae, and planktivorous rockfish was increased in the 2000 model. In the 1750 model, a very small proportion of forage fish in the diet of toothed whales (0.004 kgkm-2yr-1) was transferred to sea otters to incorporate the effect of the larger sea otter population on the diet of toothed whales. To balance chinook and coho salmon in the 2000 model, their percentages in the diet of seals and sea lions were reduced, and the transient salmon was increased. Pollock was reduced in the diet for balance, and turbot and flatfish were added, and juvenile sablefish was added to the diet to take some of the pressure off adult sablefish in the 2000 model. For subsequent balancing of adult lingcod in the 1750 model, adult lingcod was added to the diet of seals and sea lions and the 0.03 was reduced from the juvenile Pacific cod in their diet. Except for minor changes required in balancing, the 1950 diet matrix remains unaltered from 2000. After balancing, the final diet matrices are given in Appendix D. Ratfish was reduced in the 2000 diet of dogfish, and adult planktivorous rockfish was added to balance ratfish in this model. In the 1750 model the percentages of coho and chinook salmon in the diet of dogfish were reduced even more, to Back to the Future on Canada’s West Coast, Page 21  balance those compartments. Final ratfish diet is given in Appendix D Table D8. The percentage of juvenile pollock in the diet of adult pollock was reduced by 5% and the remainder went to forage fish. Cannibalism in juvenile pollock was excluded and the 5.7% was added to juvenile flatfish. Final diet matrix of pollock appears in Appendix D Table D10. In order to balance adult herring in the 1950 model it was necessary to drastically reduce it in the diet of most of its predators, particularly chinook, dogfish, inshore rockfish and lingcod. Since the 1950 diet matrix was based on 2000, it is not surprising that the much smaller biomass of herring in 1950 could not support all of its benefactors. Even still we had to accept a negative biomass accumulation of 50% per year. Although a negative biomass accumulation may be reasonable considering the damaging reduction fishery, this estimate is probably high.  The biomass accumulation for Pacific Ocean perch (-0.3 tkm-2yr-1) was too high and we reduced it to - 0.15 tkm-2yr-1 to balance the present-day model. The biomass accumulation was removed entirely for the 1950 model. To balance juvenile pollock in the 2000 model, predation by adult Pollock was shifted to juvenile turbot. To balance juvenile planktivorous rockfish in the 2000 model, predation by inshore rockfish was added to juvenile turbot. To balance the shallow water benthic fish in the 2000 model, the percentage eaten by adult halibut was added to adult flatfish. The discards in the 2000 diet of adult halibut were assumed to be detritus in the 1750 model, as no discards were available at that time.  To balance juvenile flatfish in the 2000 model, their contribution (20%) to the diet of large crabs was reduced to 10%, and the contribution of detritus was increased to 30%. These estimates were used for all four models.   ACKNOWLEDGEMENTS  We are grateful to Dr Marcelo Vasconcellos for comments on the manuscript. Thanks also to Keith Brickley of the DFO Statistical Services Unit in Ottawa for providing sport catch survey data.   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(eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports, 10(1):116 pages. Kenyon, K. W. 1975. The sea otter in the eastern Pacific Ocean. Dover Publications. 352p. Martell, S. 1999. Estimating lingcod biomass in Hecate Strait using stock reduction analysis. Pages 25-30 in: Haggan, N. and Beattie, A. I. (eds). Back to the Future: reconstructing the Hecate Strait ecosystem. Fisheries Centre Research Reports 7(3), 65 pages. Newlands, N. 1998. Box 3: Salmon Population Parameters. Page 77 in D. Pauly; T. Pitcher and D. Preikshot. (eds) Back to the Future: Reconstructing the Strait of Georgia Ecosystem. Fisheries Centre Research Reports, 6(5):99pp. Niggol, K. 1982. Data on fish species from Bering Sea and Gulf of Alaska. NOAA Tech. Mem. NMFS F/NWC-29. Palomares, M. L. D. and Pauly, D. 1998. 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US Commission of Fish and Fisheries. Riedman, M. L. and Estes, J. A. 1998. A review of the history, distribution and foraging ecology of sea otters. Pages 4-21 in G. R. Van Blarian and J. A. Estes (eds) The community ecology of sea otters. Springer Verlag: 4-21. Schweigert, J. F. 1987. Status of the Pacific Sardine, Sardinops sagax, in Canada. Canadian Field-Naturalist, 102(2):296-303. Schweigert, J. and Fort, C. 1999. Stock assessment for British Columbia herring in 1999 and forecasts of the potential catch in 2000. DFO Canadian Stock Assessment Secretariat Research Document 99/178 Saunders, M. and Andrews, W. 1996. Walleye pollock stock assessment for 1996 and recommended yield options for 1997. PSARC Working Paper G96-8. 19pp. Schreiber, D. 2002. Halibut. Pages 89-90 in: Pitcher, T., Heymans, J. J., and Vasconcellos, M. (eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports, 10(1), 116 pages. Sinclair, A. 2002. Pacific cod. Page 94 in: Pitcher, T., Heymans, J. J., and Vasconcellos, M. (eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports, 10(1), 116 pages. Sloan, N.A. 2002. Macrophytes of the Hecate Strait. Pages 110-112 in: Pitcher, T., Heymans, J. J., and Vasconcellos, M. (eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports, 10(1), 116 pages. Smith, R. L, Paul, A. J. and Paul, J. M. 1995. Minimal food requirements for Yellowfin sole in Alaska: estimates from laboratory bioenergetics. Alaska Sea Grant College Program Report No. 95-04:285-296. Trites, A. and Heise, K. 1996. Whales and dolphins. In: Pauly, D., Christensen, V. and Haggan, N. (eds) 1996. Mass-Balance Models of North-eastern Pacific Ecosystems. Fisheries Centre Research Reports, 4(1), 127 pages. Trites, A. and Pauly, D. 1998. Estimating mean body masses of marine mammals from maximum body lengths. Canadian Journal of Zoology, 76(5):886-896pp. Vasconcellos, M. and Fargo, J. 2002. A historical perspective for flatfish species in Hecate Strait. Pages. 94-96 in: Pitcher, T., Heymans, J. J., and Vasconcellos, M. (eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports 10(1):116 pages. Vasconcellos, M. and Pitcher, T.J. 2002a. Workshop notes on Sea Otters. Pages 80-81 in Pitcher, T., Heymans, J. J., and Vasconcellos, M. (eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports, 10(1):116 pages. Vasconcellos, M. and Pitcher, T. J. 2002b. Workshop notes on Seals and sea lions. Pages 83-85 in Pitcher, T., Heymans, J. J., and Vasconcellos, M. (eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports, 10(1):116 pages. Vasconcellos, M. and Pitcher, T. J. 2002c. Workshop notes on Pacific salmon. Pages 87-89 in: Pitcher, T., Heymans, J. J., and Vasconcellos, M. (eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports, 10(1):116 pages. Vasconcellos, M. and Pitcher, T. J. 2002d. Workshop notes on dogfish. Page 87 in Pitcher, T., Heymans, J. J., and Vasconcellos, M. (eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports, 10(1):116 pages. Vasconcellos, M. and Pitcher, T. J. 2002e. Workshop notes on eulachon. Pages 106-107 in Pitcher, T., Heymans, J. J., and Vasconcellos, M. (eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports, 10(1):116 pages. Vasconcellos, M. and Pitcher, T. J. 2002f. Workshop notes on forage fish. Pages 97-98 in Pitcher, T., Heymans, J. J., and Vasconcellos, M. (eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports, 10(1):116 pages. Back to the Future on Canada’s West Coast, Page 23  Vasconcellos, M. and Pitcher, T. J. 2002g. Workshop notes on halibut. Pages 91-92 in Pitcher, T., Heymans, J. J., and Vasconcellos, M. (eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports, 10(1):116 pages. Vasconcellos, M. and Pitcher, T. J. 2002h. Historic reference points for models of past ecosystems in northern British Columbia. Pages 60-67 in Pitcher, T., Heymans, J. J., and Vasconcellos, M. (eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports, 10(1):116 pages. Vasconcellos, M. and Pitcher, T. J. 2002i. Workshop notes on Invertebrates. Pages 107-108 in Pitcher, T., Heymans, J. J., and Vasconcellos, M. (eds) Information Supporting Past and Present Ecosystem Models of Northern British Columbia and the Newfoundland Shelf. Fisheries Centre Research Reports, 10(1):116 pages. Wada, Y. and Kelson, J. 1996. Seabirds of the southern B.C. shelf. Pages 55-56 in Christensen, V. and Haggan, N. (eds). Mass-Balance Models of North-eastern Pacific Ecosystems. Fisheries Centre Research Reports, Vol.4 (1):131pp. Walters, C. J. and Bonfil, R. 1999. Multispecies spatial assessment models for the British Columbia groundfish trawl fishery. Canadian Journal of Fisheries and Aquatic Sciences, 56: 601-628. Wood, C. C., Ketchen, K. S. and Beamish, R. J. 1979. Population dynamics of spiny dogfish (Squalus acanthius) in British Columbia waters. Journal of the Fisheries Research Board of Canada, 36: 647-656.    Ecosystem Models of Northern BC, Past and Present, Page 24  APPENDICES APPENDIX A.      BYCATCH AND DISCARDS Table A1: Bycatch to the shrimp trawl fishery. (Source: Hay et al. 1999) Species Catch (kg) % of target species Catch (kgkm-2yr-1)  Pink shrimp smooth 73.100     Side-stripe shrimp 8.662     Pink shrimp 3.731     Prawn 0.370     Coon stripe shrimp 0.315   Total shrimp 86.177  52.000 Eulachon 7.660 0.089 4.622 Eelpouts (Shallow water benthic fish) 1.982 0.023 1.196 Arrowtooth flounder (Turbot) 1.156 0.013 0.698 Walleye pollock 0.392 0.005 0.059   Dover sole 0.303 0.004    Flathead sole 0.901 0.010    Rex sole 0.790 0.009    English sole 0.550 0.006    Slender sole 0.505 0.006    Pacific sanddab 0.298 0.003  Total flatfish  0.039 2.019 Spotted ratfish* 2.071 0.024 1.250 Spiny dogfish* 0.943 0.011 0.569   Longnose skate* 0.388 0.004    Big skate* 0.482 0.006  Total skate  0.010 0.525  Table A2: By-catch and discards from the groundfish trawl fishery. (Source: DFO observer database. Adapted from Beattie, 2001) Compartment Catches (tonnes) Catch (t/km2) Retained Discarded Retained Discarded Coho salmon 0.003 0.038 0.000 0.001 Chinook salmon 0.118 0.684 0.002 0.010 Squid  0.116 1.544 0.002 0.022 Ratfish 3.600 716.000 0.052 10.234 Dogfish 15.800 636.000 0.226 9.082 Pollock 469.800 171.000 6.712 2.448 Forage fish - 3.300  0.040 Eulachon*    0.007 Adult herring 0.152 19.000 0.002 0.278 Adult Pacific Ocean perch 4547.000 153.000 64.959 2.184 Inshore rockfish 22.000 13.000 0.314 0.192 Adult piscivorous rockfish 1580.000 24.000 22.581 0.339 Adult planktivorous rockfish 5354.000 355.000 76.482 5.065 Adult turbot 1227.000 1826.000 17.527 26.089 Adult flatfish 3694.000 - 52.775  Juvenile halibut#   0.052 2.609 Adult halibut# 7.200 365.000 0.052 2.609 Adult Pacific cod 1271.000 107.000 18.161 1.531 Adult sablefish 42.000 225.000 0.595 3.219 Adult lingcod 483.000 91.000 6.897 1.298 Shallow water benthic fish 0.043 2.800 0.001 0.040 Skates 1141.000 480.000 16.302 6.856 Large crabs 0.185 16.000 0.003 0.225 Small crabs 0.014 2.600 0.000 0.037 Shrimp 0.047 0.292 0.001 0.004 Epifaunal invertebrates 5.735 164.000 0.082 2.347 Infaunal invertebrates - 0.203  0.003 Carnivorous jellyfish - 2.400  0.034 * It is assumed that 1/6th of the forage fish discarded is eulachon. # The catch of halibut was split into adult and juvenile halibut (50:50).  Back to the Future on Canada’s West Coast, Page 25  APPENDIX B.    PARAMETER ESTIMATION The P/B and Q/B ratios of all fish species (Tables B1 and B2) were calculated by using empirical formulas obtained from Palomares and Pauly (1998). The formula used for M is from Pauly (1980):  M = k(0.65) * Loo(-0.279) * T(0.463) or logM = 0.0066 - (0.279 * Log10(Loo)) + (0.65431*Log10(k)) + (0.4631* Log10(T)) The formula for Q/B is from (Christensen and Pauly, 1992):  Q/B = 106.37 * 0.0313Tk * Woo(-0.168) * 1.38Pf * 1.89Hd. Woo was estimated from the length-weight formula (W(g) = a * Lb) and the values used for k, Loo (cm) temperature (°C), a and b were obtained from Fishbase 2000 and references therein.  Pf was 1 for predators and zooplankton feeders and 0 for herbivores, and Hb was 1 for herbivores and 0 for predators and zooplankton feeders.  In most instances the M and Q/B estimates of juveniles were assumed to be 1.5 x that of adults and the sex ratio was assumed to be 50:50. Table B1. M estimated for all fish compartments. # Species K Loo T M* M# Juvenile M FishBase Reference   sockeye 0.58 69 12 0.68053 0.68951  1149  chum male 0.27 120 12 0.35478 0.35827    chum female 0.3 102 12 0.39755 0.40165  1150  pink 0.33 78.5 12 0.45502 0.4599   6 Transient salmon    0.47197 0.47733   7 Coho 0.98 80 12 0.91832 0.93254  4937 8 Chinook 0.13 150.3 12 0.20718 0.20857    Ratfish male 0.221 96 4 0.19932 0.20109  785  ratfish female 0.196 79 4 0.19466 0.19629  785 11 Ratfish average    0.19699 0.19869    Dogfish female 0.031 125 7 0.06693 010040  1280  Dogfish male 0.092 84.7 7 0.15131 0.22696  1280 12 Dogfish average    0.10912     Pollock female 0.092 94.4 7 0.1468 0.14755  960  Pollock male 0.097 79.8 7 0.15923 0.16008  960 14 Pollock average    0.15301 0.15382 0.22952 960  capelin male 0.48 20 7 0.66237 0.67052  1080  capelin female 0.48 19 7 0.67192 0.68018  1080  chub mackerel California 0.25 42.3 10 0.41487 0.41881  5896  chub mackerel California 1933-34 0.221 40.5 10 0.38759 0.39107    chub mackerel California 1958-70 0.244 43.6 10 0.40494 0.40874    chub mackerel California 1939-52 0.4 40 10 0.57196 0.57856    slender black smelt 0.14 27 7 0.27347 0.27537    California anchovy 0.45 16.4 10 0.79186 0.8014  907  South American pilchard 1937 0.57 25.1 10 0.81999 0.83073  841  South American pilchard 1938 0.55 29.1 10 0.76879 0.77874  841  South American pilchard 1939 0.54 29.3 10 0.75823 0.76797  841  South American pilchard 1941 0.52 30 10 0.735 0.74432  841  South American pilchard 1942 0.53 30.2 10 0.74278 0.75226  841  American shad 0.13 78.5 10 0.22824 0.22976   15 Forage fish average    0.588 0.59489   16 Eulachon 0.3 31.5 12 0.55177 0.55746   17 Herring 0.48 27 12 0.78184 0.7915 1.17276 839 19 Pacific Ocean Perch 0.13 45.3 7 0.22558 0.22707 0.33836   Copper rockfish 0.12 50 10 0.24573 0.24728  4512  yelloweye rockfish 0.05 93.5 10 0.11681 0.1171   21 Inshore rockfish    0.18127 0.18219    black rockfish 0.143 60 4 0.17125 0.17244  2012  blue rockfish 0.168 38.7 10 0.32846 0.33101  1227  chilipepper male 0.3 38.7 7 0.40592 0.41008  6998  chilipepper female 0.18 53.2 7 0.26649 0.26863  6998 23 Piscivorous rockfish    0.29303 0.29554 0.43954   puget sound rockfish 0.704 13.7 7 0.94419 0.95738  27786  puget sound rockfish 0.535 17.1 7 0.74251 0.752  27786  yellowtail rockfish male 0.153 48.5 7 0.24604 0.24784  35371  yellowtail rockfish female 0.157 52.3 7 0.24499 0.24682  35371 Ecosystem Models of Northern BC, Past and Present, Page 26  # Species K Loo T M* M# Juvenile M FishBase Reference  shortbelly rockfish female 0.211 32.4 7 0.33933 0.34229  2707  shortbelly rockfish male 0.298 29 7 0.43804 0.44252  2707  bocaccio female 0.11 87.8 7 0.16825 0.16924  6998  bocaccio male 0.13 76.6 7 0.19482 0.19611  6998  canary rockfish 0.12 78.5 7 0.18369 0.18484   25 Planktivorous rockfish    0.3891 0.39323 0.58364   butter sole male 0.36 38 4 0.35448 0.35838  4948  butter sole female 0.26 42 4 0.279 0.28167  4948  english sole female 0.243 41.6 4 0.26771 0.2702  1094  english sole male 0.347 30.7 4 0.36733 0.37131  1094  pacific sanddab 0.3 30 4 0.33633 0.33976  754  petral sole male 0.16 49 4 0.19492 0.19638  1090  petral sole female 0.167 58.6 4 0.19067 0.19213  1090  rocksole male 0.12 48.8 4 0.16186 0.16287  5830  rocksole female 0.15 55 4 0.18099 0.18229  5830  starry flounder male 0.229 44.8 4 0.25231 0.25459  1098  starry flounder female 0.192 51 4 0.21701 0.21881  1098 29 Average flatfish    0.25478 0.25712 0.38218  30 Pacific halibut 0.05 215 4 0.06369 0.06386 0.09553 950 32 Pacific cod 0.19 114 4 0.17221 0.17363 0.25832 5817 34 Sablefish 0.19 94 4 0.18174 0.18323 0.2726 5818  Lingcod female 0.18 113 7 0.21597 0.21771  34120  Lingcod male 0.27 86.1 7 0.30325 0.30622  34120 37 Lingcod average    0.25961 0.26196 0.38942 34120  green sturgeon 0.087 190 7 0.11647 0.11703  718  cabezon 0.342 57.7 7 0.39539 0.39967  1224  snowy snailfish 0.3 20 7 0.488 0.49301  871  white sturgeon 0.04 350 7 0.05927 0.05936  1766  red irish lord  53 7      kelp greenling 0.17 63.2 7 0.24472 0.24663    rock greenling  63.2 7      cutthroat trout summer 0.25 101.8 7 0.27528 0.27789    cutthroat trout winter 0.25 101.8 7     38 Shallowwater benthic feeders    0.26319 0.2656    shortfin mako 0.07 321 7 0.08735 0.0877  6100  broadnose sevengill shark 0.25 202 7 0.22738 0.22953  34307  pacific angelshark female 0.162 126 7 0.19564 0.19712  6147  pacific angelshark male 0.152 126 7 0.1877 0.18907  6147  great white shark 0.058 653 7 0.06341 0.06361  31510  basking shark 0.062 1000 7 0.05879 0.05899  9030  tope shark 0.11 175 7 0.1388 0.13961  777  blue shark male 0.18 295 7 0.16524 0.16657  6100  blue shark female 0.25 242 7 0.2162 0.21825  6100 39 Skates and sharks    0.14895 0.15005   * calculated using Pauly (1980) # calculated using Palomares and Pauly (1998)  Back to the Future on Canada’s West Coast, Page 27  Table B2: Calculations of Q/B for all fish compartments. # Species Loo a b Woo Temp. oC Pf Hd Q/B Juvenile Q/B FishBase reference   sockeye 69 0.019223 3 6315 3.51 1 0 3.93078     chum average 111 0.014083 3 19261 3.51 1 0 3.25922    pink 78.5 0.00336 3.3 6017 3.51 1 0 3.96276  7231 6 Transient salmon        3.71759   7 Coho 80 0.0112 3 5734 3.51 1 0 3.99499   8 Chinook 150.3 0.01333 3 45275 3.51 1 0 2.82329    Ratfish male 96   0 3.61       ratfish female 79   0 3.61       Dogfish female 125           Dogfish male 84.7          12 Dogfish average 104.85 0.00396 3.004 4650 3.57 1 0 3.33123  4511 13 Pollock female 94.4 0.0059 3.03 5689 3.57 1 0 3.22032  2831  Pollock male 79.8 0.0059 3.03 3419 3.57 1 0 3.50786  2831 14 Pollock average 87.1 0.0059 3.03 4554 3.57 1 0 3.36409 5.04614 2831 15 capelin male 20 0.00146 3.41 40 3.57 1 0 7.40962  1080  capelin female 19 0.00215 3.25 31 3.57 1 0 7.73913  1080  chub mackerel California 42.3 0.00137 3.394 453 3.53 1 0 5.61518  4530  slender blacksmelt 27 0.007 3 138 3.57 1 0 6.01669  0  California anchovy 16.4 0.0117 2.95 45 3.53 1 0 8.28185  1658  South American pilchard 1937 25.1 0.00761 3 120 3.53 1 0 7.01699  0  American shad 78.5 0.0065 2.959 2629 3.53 1 0 4.17953  3762 15 Forage fish average        6.60843   17 Herring 27 0.00448 3.127 134 3.51 1 0 7.50892 11.2634 12624 19 Pacific Ocean Perch 45.3 0.0149 3 1385 3.57 1 0 4.08294 6.1244   Copper rockfish 50 0.017464 3 2183 3.53 1 0 4.31219    yelloweye rockfish 93.5 0.013841 3 11313 3.53 1 0 3.27081    quillback rockfish 63.2 0.029659 3 7487 3.53 1 0 3.50571   21 Inshore rockfish        3.69624    black rockfish 60 0.021111 3 4560 3.61 1 0 2.92338    blue rockfish 38.7 0.017266 3 1001 3.53 1 0 4.91591    china rockfish 46.9 0.022541 3 2325 3.57 1 0 3.74258   23 Piscivorous rockfish        3.86062 5.79094  24 puget sound rockfish 13.7 0.0588 2.687 67 3.57 1 0 6.79755  27786  puget sound rockfish 17.1 0.0588 2.687 121 3.57 1 0 6.15024  27786  yellowtail rockfish male 48.5 0.015086 3 1721 3.57 1 0 3.93664    yellowtail rockfish female 52.3 0.015086 3 2158 3.57 1 0 3.78978    bocaccio female 87.8 0.01321 3 8941 3.57 1 0 2.98476    bocaccio male 76.6 0.01321 3 5937 3.57 1 0 3.19727    canary rockfish 78.5 0.01379 3 6671 3.57 1 0 3.13532   25 Planktivorous rockfish        4.28451 6.42676   english sole female 41.6 0.00383 3.127 443 3.61 1 0 4.32559  4511  english sole male 30.7 0.00383 3.127 171 3.61 1 0 5.07419  4511  petral sole male 49 0.00418 3.135 832 3.61 1 0 3.89082  1090  petral sole female 58.6 0.00171 3.352 1442 3.61 1 0 3.54716  1090 29 Average flatfish        4.20944 6.31416  30 Pacific halibut 215 0.00314 3.24 113248 3.61 1 0 1.70417 2.55626  32 Pacific cod 114 0.0224 2.89 19711 3.61 1 0 2.28603 3.42904 4511  Lingcod female 113           Lingcod male 86.1          37 Lingcod average 99.55 0.0133 3 13121 3.57 1 0 2.79848 3.93799  38 green sturgeon 190 0.005934 3 40703 3.57   1.67666    cabezon 57.7 0.029141 3 5598 3.57   2.33987    white sturgeon 350 0.012218 3 523858 3.57   1.09153    red irish lord 53 0.028241 3 4204 3.57   2.45515    kelp greenling 63.2 0.015583 3 3934 3.57   2.48276    rock greenling 63.2 0.012969 3 3274 3.57   2.56055    cutthroat trout summer 101.8 0.0138 2.948 11448 3.57   2.0749  3852  cutthroat trout winter 101.8 0.0234 2.827 11095 3.57   2.08585  3852 38 Shallowwater benthic feeders        2.09591    shortfin mako 321 0.05 2.32 32663 3.57   1.7398  8588  broadnose sevengill shark 202   0 3.57       pacific angelshark female 126   0 3.57       pacific angelshark male 126   0 3.57       great white shark 653 0.00758 3.085 3661647 3.57   0.78734  27093  basking shark 1000 0.00494 3 4940000 3.57   0.74871  6032  tope shark 175 0.0181 2.72 22842 3.57   1.84754    blue shark male 295 0.0131 3.2 1048822 3.57   0.97137  776  blue shark female 242 0.0131 3.2 556520 3.57   1.08049  776 39 Skates and sharks        1.19588    Ecosystem Models of Northern BC, Past and Present, Page 28  APPENDIX C.   PARAMETERS USED IN MODELS Table C1. Basic parameters for the 2000, 1950, 1900 and 1750 Ecopath models. Values in bold were calculated by Ecopath.  Biomass (tkm-2) Production/Biomass ratio (yr-1) Consumption/Biomass ratio (yr-1) Groups 2000 1950 1900 1750 2000 1950 1900 1750 2000 1950 1900 1750 Sea otters 0.0001 0.000 0.0001 0.0016 0.130 0.130 0.130 0.130 101.500 101.500 101.500 101.500 Mysticetae 1.3390 1.339 1.5410 2.6720 0.020 0.020 0.020 0.020 9.100 9.100 8.000 8.000 Odontocetae 0.0613 0.061 0.0656 0.0660 0.040 0.020 0.040 0.040 15.500 15.500 15.600 15.600 Seals, sea lions 0.0520 0.057 0.0690 0.0800 0.060 0.060 0.060 0.060 15.100 15.100 15.100 15.100 Seabirds 0.0074 0.011 0.0147 0.0074 0.100 0.100 0.100 0.100 105.200 105.200 105.200 105.200 Transient salmon 0.5880 0.754 0.8400 1.0080 2.480 2.480 0.621 0.517 8.330 8.330 3.718 3.718 Coho salmon 0.0240 0.067 0.0800 0.0960 2.760 2.760 1.069 1.157 13.800 13.800 3.995 3.995 Chinook salmon 0.0180 0.026 0.1200 0.1440 2.160 2.160 0.364 0.366 10.800 10.800 2.823 2.823 Small squid 0.8446 0.955 0.7955 1.2068 6.023 6.023 6.023 6.023 34.675 34.675 34.675 34.675 Squid 0.2833 0.316 0.2587 0.3986 6.023 6.023 6.023 6.023 34.675 34.675 34.675 34.675 Ratfish 0.5170 0.517 0.1828 0.2618 0.099 0.099 0.199 0.199 1.400 1.400 1.400 1.400 Dogfish 0.9090 0.800 0.4761 1.3635 0.099 0.099 0.140 0.110 2.719 2.719 3.330 3.330 Juvenile pollock 0.1320 0.132 0.9264 1.3177 1.061 1.060 0.230 0.230 5.305 5.305 5.046 5.046 Pollock 0.3590 0.359 0.4795 0.6218 0.263 0.263 0.154 0.153 1.168 1.168 3.364 3.364 Forage fish 8.4847 9.554 24.603 32.501 1.432 1.432 0.588 0.595 8.395 8.395 6.608 6.608 Eulachon 1.6613 1.893 5.0332 7.3152 1.432 1.432 0.600 0.600 8.395 8.395 6.608 6.608 Juvenile herring 2.2650 1.317 3.7287 5.4463 2.190 2.190 1.173 1.173 10.950 10.950 11.263 11.263 Adult herring 2.2650 0.748 2.4798 7.5033 0.683 0.683 0.800 0.792 5.840 5.840 7.509 7.509 Juvenile POP 0.0650 0.036 0.1531 0.2132 0.672 0.672 0.338 0.338 3.210 3.210 6.124 6.124 Adult POP 1.8190 1.019 1.0111 1.4039 0.144 0.144 0.227 0.227 2.140 2.140 4.083 4.083 Inshore rockfish 0.1000 0.100 0.0814 0.0959 0.190 0.190 0.182 0.182 5.688 5.688 5.544 3.696 Juvenile piscivorous rockfish 0.0070 0.008 0.0158 0.0198 0.261 0.261 0.261 0.261 1.890 1.890 1.890 1.890 Adult piscivorous rockfish 0.6540 0.753 0.1186 0.1375 0.037 0.037 0.037 0.037 1.260 1.260 1.260 1.260 Juvenile planktivorous rockfish 0.1360 0.189 0.1337 0.2067 0.261 0.261 0.261 0.261 3.210 3.210 3.210 3.210 Adult planktivorous rockfish 1.2070 1.664 1.2862 2.0859 0.068 0.068 0.068 0.068 2.140 2.140 2.140 2.140 Juvenile turbot 0.2180 0.218 0.1697 0.2480 0.330 0.330 0.330 0.330 2.172 2.172 2.172 2.172 Adult turbot 1.5300 1.530 1.3415 2.1965 0.220 0.220 0.220 0.220 1.983 1.983 1.983 1.983 Juvenile flatfish 0.2590 0.150 1.6062 2.5827 1.935 1.935 0.382 0.382 6.023 6.023 6.314 6.314 Adult flatfish 0.3920 0.221 1.0143 1.7652 0.949 0.949 0.257 0.257 4.270 4.270 4.209 4.209 Juvenile halibut 0.6080 0.406 0.2955 0.4446 0.600 0.600 0.116 0.099 1.460 1.460 2.556 2.556 Adult halibut 0.6080 0.429 0.6080 1.0000 0.400 0.400 0.084 0.067 1.095 1.095 1.704 1.704 Juvenile Pacific cod 0.0890 0.047 0.3073 0.4645 1.980 1.980 0.258 0.258 7.500 7.500 3.429 3.429 Adult Pacific cod 0.1630 0.086 1.2192 2.0392 1.320 1.320 0.174 0.174 4.000 4.000 2.286 2.286 Juvenile sablefish 0.1190 0.238 0.1078 0.1805 0.600 0.600 0.273 0.273 7.000 7.000 7.000 7.000 Adult sablefish 0.3010 0.602 0.1374 0.1912 0.276 0.276 0.184 0.183 3.730 3.730 3.730 3.730 Juvenile lingcod 0.0310 0.078 0.0045 0.0056 1.200 1.200 0.389 0.389 3.300 3.300 3.938 3.938 Adult lingcod 0.0340 0.085 0.1191 0.1476 0.800 0.800 0.300 0.262 3.300 3.300 2.798 2.798 Shallow-water benthic fish 0.5090 0.509 4.4640 7.5060 1.500 1.500 0.266 0.266 5.256 5.256 2.096 2.096 Skates 0.3350 0.335 0.1669 0.2393 0.310 0.310 0.150 0.150 1.240 1.240 1.196 1.196 Large crabs 0.4421 0.310 0.3878 0.6525 1.500 1.500 1.500 1.500 5.000 5.000 5.000 5.000 Small crabs 0.6495 0.574 1.4577 2.4070 3.500 3.500 3.500 3.500 14.000 8.750 14.000 14.000 Commercial shrimp 0.0610 0.039 0.0466 0.0704 11.475 11.480 5.700 5.700 45.900 76.533 22.800 22.800 Epifaunal invertebrates 13.448 11.584 28.604 42.835 1.448 1.448 1.448 1.448 16.089 4.052 16.089 16.089 Infaunal carnivorous i t b t 13.2451 13.245 4.9530 8.2054 2.000 2.000 2.000 2.000 22.222 22.220 22.222 22.222 Infaunal invertebrate d t iti 34.3051 34.305 23.450 39.280 1.349 1.349 1.300 1.300 14.989 14.990 14.444 14.444 Carnivorous jellyfish 3.0000 3.000 3.3628 4.6258 18.000 18.000 18.000 18.000 60.000 60.000 60.000 60.000 Euphausiids 8.7000 8.700 12.606 22.662 6.100 6.000 6.000 6.000 24.820 24.820 24.820 24.820 Copepods 4.6670 4.667 8.6707 13.128 27.000 27.000 27.000 27.000 90.000 90.000 99.000 99.000 Corals and sponges 1.9286 1.9286 19.286 19.286 0.010 0.010 0.010 0.010 2.000 2.000 2.000 2.000 Macrophytes 5.2800 5.280 5.2800 10.5600 5.256 5.256 5.256 5.256 -  - - Phytoplankton 15.4060 15.406 15.4060 15.4060 178.502 178.502 178.502 178.502 -  - - Discards 0.0720 0.072 - - - - - - -  - - Back to the Future on Canada’s West Coast, Page 29  APPENDIX D.    DIET MATRICES  Table D1: Mysticetae diet.  2000 1950 1900 1750 Forage fish 0.014 0.014 0.014 0.014 Adult herring 0.010 0.001 0.010 0.010 Epifaunal invertebrates 0.037 0.037 0.037 0.037 Infaunal carn. invert. 0.037 0.045 0.037 0.037 Infaunal invert. detritivores 0.658 0.658 0.658 0.658 Euphausiids 0.226 0.226 0.226 0.226 Copepods 0.020 0.020 0.020 0.020  Table D2: Odontocetae diet.  2000 1950 1900 1750 Seals, sea lions 0.001 0.001 0.001 0.001 Transient salmon 0.041 0.041 0.050 0.050 Coho salmon 0.005 0.011 0.005 0.005 Chinook salmon 0.003 0.005 0.005 0.005 Small squid 0.202 0.202 0.202 0.202 Squid 0.224 0.224 0.224 0.224 Ratfish 0.026 0.026 0.026 0.026 Forage fish 0.162 0.162 0.162 0.161 Eulachon 0.032 0.032 0.032 0.032 Juvenile herring 0.026 0.026 0.026 0.026 Adult herring 0.056 0.040 0.056 0.056 Juvenile POP 0.020 0.005 0.020 0.020 Inshore rockfish 0.002 0.003 0.005 0.005 Juv. planktivorous rockfish 0.006 0.010 0.006 0.006 Ad. planktivorous rockfish 0.020 0.011 0.020 0.020 Juvenile turbot 0.027 0.016 0.026 0.026 Large crabs 0.021 0.019 0.019 0.019 Euphausiids 0.115 0.162 0.115 0.115 Discards 0.012 0.005    Table D3: Seal and sea lion diet.  2000 1950 1900 1750 Transient salmon 0.080 0.080 0.080 0.080 Coho salmon 0.002 0.002 0.002 0.002 Chinook salmon 0.005 0.005 0.005 0.005 Small squid 0.108 0.108 0.108 0.108 Squid 0.011 0.011 0.011 0.011 Dogfish 0.030 0.030 0.030 0.030 Pollock 0.040 0.040 0.040 0.040 Forage fish 0.070 0.070 0.070 0.070 Juvenile herring 0.280 0.280 0.280 0.280 Adult POP 0.121 0.061 0.121 0.121 Inshore rockfish 0.002 0.003 0.003 0.003 Ad. picivorous rockfish 0.004 0.000 0.004 0.004 Juv. planktivorous rockfish 0.004 0.004 0.004 0.004 Ad. planktivorous rockfish 0.035 0.004 0.035 0.035 Adult turbot 0.063 0.010 0.062 0.062 Adult flatfish 0.060 0.062 0.060 0.060 Juvenile Pacific cod 0.060 0.050 0.030 0.030 Juvenile sablefish 0.006 0.020 0.006 0.006 Adult sablefish 0.020 0.031 0.020 0.020 Adult lingcod  0.130 0.030 0.030  Ecosystem Models of Northern BC, Past and Present, Page 30  Table D4: Seabird diet.  2000 1950 1900 1750 Transient salmon  0.054 0.052 0.052 Small squid 0.050 0.069 0.069 0.069 Squid 0.050    Forage fish 0.250 0.263 0.263 0.263 Eulachon 0.050 0.079 0.079 0.079 Juvenile herring 0.100 0.105 0.105 0.105 Adult herring 0.050 0.003 0.079 0.079 Small crabs 0.100 0.041 0.041 0.041 Epifaunal invertebrates  0.041 0.041 0.041 Carnivorous jellyfish  0.036 0.001 0.001 Euphausiids 0.300 0.154 0.115 0.115 Copepods  0.156 0.155 0.156 Discards 0.003    Detritus 0.047     Table D5: Coho diet.  2000 1950 1900 1750 Squid 0.300 0.300 0.300 0.300 Forage fish 0.167 0.167 0.167 0.167 Eulachon 0.033 0.033 0.033 0.033 Adult herring 0.250 0.250 0.250 0.250 Euphausiids 0.250 0.250 0.250 0.250  Table D6: Chinook diet.  2000 1950 1900 1750 Forage fish 0.333 0.333 0.333 0.333 Eulachon 0.067 0.067 0.067 0.067 Adult herring 0.400 0.400 0.400 0.400 Euphausiids 0.200 0.200 0.200 0.200  Table D7: Squid diet. Juvenile Adult  2000 1950 1900 1750 2000 1950 1900 1750 Small squid     0.347 0.347 0.347 0.347 Forage fish 0.167 0.167 0.167 0.100 0.327 0.327 0.327 0.327 Eulachon 0.033 0.033 0.033 0.033 0.065 0.065 0.065 0.065 Juvenile herring 0.100 0.040 0.100 0.100     Adult herring    0.067     Carnivorous jellyfish 0.250 0.250 0.250 0.250 0.117 0.117 0.117 0.117 Euphausiids 0.330 0.390 0.330 0.330 0.103 0.103 0.103 0.103 Copepods 0.120 0.120 0.120 0.120 0.041 0.041 0.041 0.041  Table D8: Ratfish diet.  2000 1950 1900 1750 Forage fish 0.278 0.278 0.278 0.278 Eulachon 0.056 0.056 0.056 0.056 Epifaunal invertebrates 0.183 0.183 0.183 0.183 Infaunal carn. invert. 0.070 0.070 0.070 0.070 Infaunal invert. detritivores 0.080 0.080 0.080 0.080 Euphausiids 0.334 0.334 0.334 0.334  Back to the Future on Canada’s West Coast, Page 31  Table D9: Dogfish diet.  2000 1950 1900 1750 Transient salmon 0.009 0.054 0.023 0.023 Coho salmon 0.010 0.015 0.003 0.003 Chinook salmon 0.001 0.010 0.003 0.003 Small squid 0.033 0.033 0.033 0.033 Squid 0.055 0.055 0.055 0.055 Ratfish 0.005 0.006 0.005 0.005 Forage fish 0.077 0.077 0.077 0.077 Eulachon 0.015 0.015 0.015 0.015 Juvenile herring 0.041 0.041 0.041 0.041 Adult herring 0.100 0.010 0.100 0.100 Juvenile POP 0.004 0.004 0.004 0.004 Adult POP 0.003 0.003 0.003 0.003 Juv. planktivorous rockfish 0.003 0.003 0.003 0.003 Ad. planktivorous rockfish 0.015 0.005 0.015 0.015 Juvenile turbot 0.005 0.005 0.005 0.005 Adult turbot 0.013 0.020 0.013 0.013 Juvenile flatfish 0.020 0.010 0.020 0.020 Adult flatfish 0.028 0.020 0.028 0.028 Juvenile Pacific cod 0.008 0.008 0.008 0.008 Adult Pacific cod 0.007 0.005 0.007 0.007 Juvenile sablefish 0.004 0.014 0.004 0.004 Adult sablefish 0.002 0.020 0.002 0.002 Shallowwater benthic fish 0.017 0.017 0.017 0.017 Large crabs 0.046 0.037 0.037 0.037 Small crabs 0.036 0.036 0.036 0.036 Epifaunal invertebrates 0.052 0.052 0.052 0.052 Infaunal carn. invert. 0.017 0.019 0.017 0.017 Infaunal invert. detritivores 0.006 0.008 0.006 0.006 Carnivorous jellyfish 0.039 0.039 0.039 0.039 Euphausiids 0.143 0.149 0.143 0.143 Copepods 0.100 0.130 0.100 0.100 Detritus 0.086 0.080 0.086 0.086  Table D10: Pollock diet.  2000 1950 1900 1750 Squid 0.031 0.031 0.031 0.031 Juvenile pollock 0.100 0.100 0.100 0.100 Forage fish 0.198 0.198 0.198 0.198 Eulachon 0.028 0.028 0.028 0.028 Epifaunal invertebrates 0.022 0.022 0.022 0.022 Euphausiids 0.461 0.461 0.461 0.461 Copepods 0.160 0.160 0.160 0.160  Table D11: Forage fish diet. Forage fish Eulachon  2000 1950 1900 1750 2000 1950 1900 1750 Epifaunal invertebrates 0.100 0.100 0.100 0.100 0.100 0.100 0.100 0.100 Carnivorous jellyfish 0.200 0.200 0.200 0.200 0.200 0.200 0.200 0.200 Euphausiids 0.150 0.150 0.150 0.150 0.100 0.100 0.100 0.100 Copepods 0.500 0.500 0.500 0.500 0.600 0.600 0.600 0.600 Detritus 0.050 0.050 0.050 0.050      Table D12: Herring diet. Juvenile Adult  2000 1950 1900 1750 2000 1950 1900 1750 Euphausiids 0.100 0.100 0.100 0.100 0.900 0.900 0.900 0.900 Copepods 0.900 0.900 0.900 0.900 0.100 0.100 0.100 0.100  Ecosystem Models of Northern BC, Past and Present, Page 32  Table D13:  Inshore rockfish diet.  2000 1950 1900 1750 Forage fish 0.060 0.060 0.060 0.060 Eulachon 0.012 0.012 0.012 0.012 Juvenile herring 0.300 0.300 0.300 0.300 Adult herring 0.325 0.050 0.325 0.325 Shallowwater benthic fish 0.045 0.045 0.045 0.045 Large crabs 0.005 0.005 0.005 0.005 Small crabs 0.107 0.107 0.107 0.107 Commercial shrimp 0.040 0.095 0.040 0.040 Epifaunal invertebrates 0.050 0.050 0.050 0.050 Infaunal carn. invert. 0.004 0.124 0.004 0.004 Euphausiids 0.052 0.152 0.052 0.052  Table D14: Piscivorous rockfish diet. Juvenile Adult  2000 1950 1900 1750 2000 1950 1900 1750 Squid     0.140 0.140 0.140 0.140 Forage fish     0.027 0.027 0.027 0.027 Eulachon     0.005 0.005 0.005 0.005 Skates     0.069 0.069 0.069 0.069 Small crabs 0.100 0.100 0.100 0.100 0.130 0.130 0.130 0.130 Commercial shrimp 0.100 0.100 0.100 0.100     Epifaunal invertebrates 0.100 0.100 0.100 0.100 0.254 0.254 0.254 0.254 Infaunal invert. detritivores     0.040 0.040 0.040 0.040 Carnivorous jellyfish     0.038 0.038 0.038 0.038 Euphausiids 0.400 0.400 0.400 0.400 0.196 0.196 0.196 0.196 Copepods 0.300 0.300 0.300 0.300     Detritus     0.101 0.101 0.101 0.101  Table D15: Planktivorous rockfish. Juvenile Adult  2000 1950 1900 1750 2000 1950 1900 1750 Small squid     0.092 0.092 0.092 0.092 Squid     0.110 0.110 0.110 0.110 Forage fish     0.028 0.028 0.028 0.028 Eulachon     0.006 0.006 0.006 0.006 Juvenile herring     0.109 0.109 0.109 0.109 Carnivorous jellyfish     0.006 0.006 0.006 0.006 Euphausiids 0.500 0.500 0.500 0.500 0.574 0.574 0.574 0.574 Copepods 0.500 0.500 0.500 0.500 0.075 0.075 0.075 0.075  Back to the Future on Canada’s West Coast, Page 33  Table D16: Turbot diet. Juvenile Adult  2000 1950 1900 1750 2000 1950 1900 1750 Small squid 0.174 0.174 0.174 0.174 0.207 0.207 0.207 0.207 Squid     0.178 0.178 0.178 0.178 Juvenile pollock 0.030 0.030 0.030 0.030 0.009 0.009 0.009 0.009 Pollock 0.070 0.070 0.070 0.070 0.001 0.001 0.001 0.001 Forage fish 0.111 0.111 0.111 0.111 0.107 0.107 0.107 0.107 Eulachon 0.022 0.022 0.022 0.022 0.021 0.021 0.021 0.021 Juvenile herring 0.150 0.150 0.150 0.150 0.099 0.099 0.099 0.099 Adult herring 0.088 0.048 0.088 0.088 0.010 0.010 0.010 0.010 Juvenile POP     0.001 0.001 0.001 0.001 Adult POP     0.025 0.020 0.025 0.025 Inshore rockfish 0.007 0.007 0.007 0.007     Juv. picivorous rockfish 0.001 0.001 0.001 0.001     Juv. planktivorous rockfish 0.017 0.017 0.017 0.017     Juvenile turbot     0.001 0.001 0.001 0.001 Juvenile flatfish 0.033 0.033 0.033 0.033 0.020 0.020 0.020 0.020 Adult flatfish     0.005 0.005 0.005 0.005 Adult Pacific cod     0.026 0.003 0.026 0.026 Shallowwater benthic fish     0.123 0.128 0.133 0.133 Small crabs 0.100 0.100 0.100 0.100     Commercial shrimp 0.100 0.100 0.100 0.100 0.021 0.044 0.021 0.021 Epifaunal invertebrates 0.033 0.033 0.035 0.035 0.024 0.024 0.024 0.024 Euphausiids 0.062 0.074 0.062 0.062 0.050 0.050 0.050 0.050 Discards 0.002    0.010    Detritus  0.030   0.062 0.010 0.062 0.062 Import      0.062    Table D17: Flatfish diet. Juvenile Adult  2000 1950 1900 1750 2000 1950 1900 1750 Forage fish 0.050 0.050 0.050 0.050 0.154 0.154 0.154 0.154 Eulachon 0.010 0.010 0.010 0.010 0.031 0.031 0.031 0.031 Small crabs 0.068 0.068 0.068 0.068 0.038 0.038 0.038 0.038 Epifaunal invertebrates 0.046 0.046 0.046 0.046 0.046 0.046 0.046 0.046 Infaunal carn. invert. 0.373 0.373 0.373 0.373 0.272 0.272 0.272 0.272 Infaunal invert. detritivores 0.453 0.453 0.453 0.453 0.455 0.455 0.455 0.455 Euphausiids     0.004 0.004 0.004 0.004  Table D18: Halibut diet. Juvenile Adult  2000 1950 1900 1750 2000 1950 1900 1750 Small squid 0.033 0.033 0.033 0.033 0.051 0.051 0.051 0.051 Squid 0.030 0.030 0.030 0.030 0.076 0.076 0.076 0.076 Forage fish 0.055 0.055 0.055 0.055 0.014 0.014 0.014 0.014 Eulachon 0.011 0.011 0.011 0.011 0.003 0.003 0.003 0.003 Juvenile herring 0.050 0.050 0.050 0.050     Adult herring     0.100 0.020 0.100 0.100 Juvenile POP 0.003 0.003 0.003 0.003     Adult POP     0.020 0.020 0.020 0.020 Juv. planktivorous rockfish     0.005 0.005 0.005 0.005 Ad. planktivorous rockfish     0.002 0.001 0.002 0.002 Adult turbot     0.043 0.074 0.043 0.043 Juvenile flatfish 0.020 0.020 0.020 0.020     Adult flatfish     0.123 0.123 0.123 0.123 Juvenile Pacific cod 0.008 0.008 0.008 0.008     Adult Pacific cod     0.100 0.060 0.100 0.100 Shallowwater benthic fish 0.055 0.055 0.055 0.055     Skates     0.013 0.053 0.013 0.013 Large crabs 0.300 0.300 0.300 0.300 0.210 0.210 0.210 0.210 Small crabs 0.300 0.300 0.300 0.300 0.140 0.140 0.140 0.140 Commercial shrimp 0.060 0.060 0.060 0.060     Epifaunal invertebrates     0.060 0.110 0.060 0.060 Discards     0.040    Detritus 0.075 0.075 0.075 0.075  0.040 0.040 0.040 Ecosystem Models of Northern BC, Past and Present, Page 34  Table D19: Pacific cod diet. Juvenile Adult  2000 1950 1900 1750 2000 1950 1900 1750 Forage fish     0.393 0.393 0.393 0.393 Eulachon     0.079 0.079 0.079 0.079 Juvenile herring     0.009 0.009 0.009 0.009 Adult herring     0.253 0.153 0.253 0.253 Adult turbot     0.054 0.154 0.054 0.054 Shallowwater benthic fish     0.212 0.212 0.212 0.212 Small crabs 0.027 0.027 0.027 0.027     Epifaunal invertebrates 0.310 0.310 0.310 0.310     Infaunal carn. invert. 0.079 0.079 0.079 0.079     Infaunal invert. detritivores 0.263 0.263 0.263 0.263     Euphausiids 0.115 0.115 0.115 0.115     Copepods 0.057 0.057 0.057 0.057     Detritus 0.149 0.149 0.149 0.149      Table D20: Sablefish diet. Juvenile Adult  2000 1950 1900 1750 2000 1950 1900 1750 Small squid 0.018 0.018 0.018 0.018  0.050   Juvenile pollock     0.010 0.010 0.010 0.010 Forage fish 0.025 0.025 0.025 0.025 0.333 0.333 0.333 0.333 Eulachon 0.005 0.005 0.005 0.005 0.067 0.067 0.067 0.067 Juvenile herring 0.020 0.020 0.020 0.020     Adult herring 0.020 0.020 0.020 0.020 0.100 0.010 0.100 0.100 Juvenile POP 0.001  0.001 0.001     Adult POP  0.001       Juv. planktivorous rockfish 0.001 0.001 0.001 0.001 0.005 0.005 0.005 0.005 Juvenile turbot 0.010 0.010 0.010 0.010 0.010 0.010 0.010 0.010 Juvenile flatfish     0.010 0.010 0.010 0.010 Juvenile halibut     0.045 0.045 0.045 0.045 Juvenile Pacific cod     0.010 0.005 0.010 0.010 Juvenile sablefish     0.030 0.030 0.030 0.030 Small crabs     0.010 0.010 0.010 0.010 Commercial shrimp     0.010 0.015 0.010 0.010 Epifaunal invertebrates 0.020 0.020 0.020 0.020 0.010 0.010 0.010 0.010 Carnivorous jellyfish 0.050 0.050 0.050 0.050 0.350 0.390 0.350 0.350 Euphausiids 0.830 0.830 0.830 0.830      Table D21: Lingcod diet. Juvenile Adult  2000 1950 1900 1750 2000 1950 1900 1750 Forage fish 0.167 0.177 0.167 0.167 0.317 0.317 0.317 0.317 Eulachon 0.033 0.033 0.033 0.033 0.063 0.063 0.063 0.063 Juvenile herring 0.100 0.200 0.100 0.100 0.050 0.050 0.050 0.050 Adult herring 0.100  0.100 0.100 0.370 0.159 0.370 0.370 Juvenile POP     0.050 0.020 0.050 0.050 Inshore rockfish     0.010 0.010 0.010 0.010 Juv. picivorous rockfish     0.010 0.005 0.010 0.010 Juv. planktivorous rockfish     0.010 0.020 0.010 0.010 Juvenile turbot     0.010 0.010 0.010 0.010 Juvenile flatfish 0.200 0.180 0.200 0.200 0.005 0.010 0.005 0.005 Juvenile Pacific cod 0.200 0.150 0.200 0.200 0.050 0.010 0.050 0.050 Adult Pacific cod     0.050 0.030 0.050 0.050 Juvenile lingcod     0.005 0.280 0.005 0.005 Small crabs  0.100       Commercial shrimp 0.100 0.160 0.100 0.100     Epifaunal invertebrates 0.040  0.040 0.040     Infaunal carn. invert. 0.030  0.030 0.030     Infaunal invert. detritivores 0.030  0.030 0.030     Detritus      0.016    Back to the Future on Canada’s West Coast, Page 35  Table D22: Shallow water benthic fish diet.  2000 1950 1900 1750 Squid 0.001 0.001 0.001 0.001 Forage fish 0.198 0.198 0.198 0.198 Eulachon 0.040 0.040 0.040 0.040 Shallowwater benthic fish 0.010 0.010 0.010 0.010 Small crabs 0.333 0.333 0.333 0.333 Commercial shrimp 0.004 0.004 0.004 0.004 Epifaunal invertebrates 0.037 0.037 0.037 0.037 Infaunal carn. invert. 0.191 0.191 0.191 0.191 Infaunal invert. detritivores 0.096 0.096 0.096 0.096 Euphausiids 0.025 0.025 0.025 0.025 Copepods 0.048 0.048 0.048 0.048 Detritus 0.017 0.017 0.017 0.017  Table D23: Skate diet.  2000 1950 1900 1750 Forage fish 0.238 0.238 0.238 0.238 Eulachon 0.048 0.048 0.048 0.048 Large crabs 0.140 0.140 0.140 0.140 Small crabs 0.250 0.250 0.250 0.250 Commercial shrimp 0.100 0.100 0.100 0.100 Epifaunal invertebrates 0.100 0.100 0.100 0.100 Infaunal carn. invert. 0.050 0.050 0.050 0.050 Infaunal invert. detritivores 0.050 0.050 0.050 0.050 Detritus 0.024 0.024 0.024 0.024  Table D24: Crab diet. Large Small  2000 1950 1900 1750 2000 1950 1900 1750 Juvenile flatfish 0.100 0.060 0.100 0.100     Small crabs 0.100 0.100 0.100 0.100     Commercial shrimp 0.015 0.015 0.015 0.015     Epifaunal invertebrates 0.435 0.435 0.435 0.435 0.800 0.800 0.800 0.800 Infaunal carn. invert. 0.025 0.065 0.025 0.025 0.100 0.100 0.100 0.100 Infaunal invert. detritivores 0.025 0.025 0.025 0.025 0.100 0.100 0.100 0.100 Detritus 0.300 0.300 0.300 0.300      Table D25: Commercial shrimp diet.  2000 1950 1900 1750 Euphausiids 0.300 0.300 0.300 0.300 Copepods 0.200 0.200 0.200 0.200 Detritus 0.500 0.500 0.500 0.500  Table D26: Invertebrate diet. Epifaunal Infaunal carn. Infaunal detrit.  All periods All periods All periods Infaunal invert. detritivores  0.100  Macrophytes 0.001   Detritus 0.999 0.900 1.000  Table D27: Carnivorous jellyfish.  All Periods Carnivorous jellyfish 0.050 Copepods 0.050 Detritus 0.900  Table D28: Euphausiid and copepod diet. Euphausiid Copepod  All periods All periods Copepods 0.200  Phytoplankton 0.800 1.000  Ecosystem Models of Northern BC, Past and Present, Page 36  APPENDIX E.   NON-MARKET PRICES Non-market Prices: (Beattie 2001) suggested a non-market price for all marine mammals from the money made by wildlife viewing, scuba diving and kayaking in the ecosystem, which brings in $22 million, $8 million and $14 million respectively. Table E1: Non-market prices. Activity Functional group Biomass (t/km2) Biomass (tonnes) Value  ($/kg) Total value ($/kg) Wildlife viewing  Mysticetae 0.310 22,940 0.719   Odontocetae 0.022 1,628 1.351   Seals/sea lions  0.052 3,848 0.572   Sea birds 0.016 1,184 0.929  Kayaking Mysticetae 0.310 22,940 0.076 *0.796  Odontocetae 0.022 1,628 1.075 *2.426  Seals/sea lions 0.052 3,848 0.455 *1.027  Sea birds 0.016 1,184 1.478 *2.407 Scuba diving Inshore rockfish 0.100 7,400 0.270 0.270  Shallow water benthic fish 5.280 390,720 0.005 0.005  Epifaunal invertebrates 5.280 390,720 0.005 0.005  Kelp 5.280 390,720 0.005 0.005 *Total value includes value from wildlife viewing and kayaking. (Source: Beattie, 2001)  (Beattie 2001) calculates non-market values assuming that all the management costs are spent on marine management and that it is equal on all salmon species.  Table E2: Management costs in Pacific salmon. (Source: Beattie, 2001) Species    Biomass (t/km2) Biomass (tonne) Management cost (tonne) Management cost ($/tonne) Management cost ($/kg) Coho salmon 0.024 1776 17.5 9853.60 9.85 Chinook salmon 0.018 1332 17.5 13138.14 13.14   APPENDIX F.    LANDINGS Table F1: 2000 Landings  Group Name Groundfish trawl Sable Herring gillnet Groundfish hook&line Salmon gillnet Crab trap Shrimp / prawn trap Other Inv. Halibut hook&line Salmon troll Salmon seine Salmon troll freezer Herring seine Shrimp trawl Eulachon Longline Recreational Total Transient salmon    0.187     0.007 0.190 0.028     0.002 0.414 Coho salmon     0.001     0.002 <0.001 0.003     0.005 0.011 Chinook salmon <0.001    <0.001     <0.001 <0.001 0.002     0.027 0.030 Squid <0.001            <0.001     <0.001 Ratfish <0.001                 <0.001 Dogfish <0.001               0.023  0.023 Pollock 0.007                 0.007 Eulachon               0.003   0.003 Adult herring <0.001  0.121          0.068     0.189 Adult POP 0.065                 0.065 Inshore rockfish <0.001   0.003     0.004        0.003 0.010 Adult pisc. rockfish 0.023   0.002             0.002 0.027 Adult plank. rockfish 0.076                 0.076 Adult turbot 0.018                 0.018 Adult flatfish 0.053                 0.053 Juvenile halibut <0.001        0.028        0.001 0.029 Adult halibut <0.001        0.028        0.014 0.042 Adult Pacific cod 0.018        0.002         0.020 Adult sablefish <0.001 0.055       0.003         0.059 Juvenile lingcod                 0.002 0.002 Adult lingcod 0.007                0.001 0.008 Shallowwater benthic fish <0.001                 <0.001 Skates 0.016                 0.016 Large crabs <0.001     0.053           0.002 0.055 Commercial shrimp <0.001      0.006       0.052   <0.001 0.058 Epifaunal invertebrates <0.001       0.078         <0.001 0.078 Sum 0.284 0.055 0.121 0.005 0.189 0.053 0.006 0.078 0.064 0.009 0.190 0.032 0.068 0.052 0.003 0.023 0.060 1.292 Ecosystem Models of Northern BC, Past and Present, Page 38  Table F2: 1950 Landings. Group Name Groundfish trawl Sable Herring gillnet Ground H+L Salmon gillnet Crab trap Shrimp / prawn trap Other Inv. Halibut H+L Salmon troll Salmon seine Salmon troll freezer Herring seine Shrimp trawl Eulachon Longline Seine nets Recreational Sea lion shooting Total Seals, sea lions                   0.001 0.001 Transient salmon    0.181     0.005 0.208 0.005      <0.001  0.398 Coho salmon     0.020     0.014 0.012 0.014      <0.001  0.061 Chinook salmon     0.006     0.006 0.001 0.006      0.002  0.021 Dogfish                0.034    0.034 Pollock 0.006                   0.006 Forage fish                 0.006   0.006 Eulachon               <0.001     <0.001 Adult herring   <0.001          0.232    0.232   0.465 Adult POP 0.002   <0.001            <0.001    0.003 Inshore rockfish    0.002     0.002         <0.001  0.004 Adult pisc. rockfish 0.010   0.001              <0.001  0.011 Adult plank. rockfish 0.036                 <0.001  0.036 Adult turbot 0.003                   0.003 Adult flatfish 0.039                   0.039 Juvenile halibut         <0.001           <0.001 Adult halibut 0.097        <0.001         0.001  0.099 Adult Pacific cod 0.019               <0.001 0.033   0.052 Adult sablefish 0.002 0.004                  0.006 Juvenile lingcod                  0.003  0.003 Adult lingcod 0.031   0.009           0.008   0.002  0.050 Skates <0.001               <0.001    <0.001 Large crabs <0.001     0.005            <0.001  0.005 Commercial shrimp      0.001       <0.001    <0.001  0.002 Epifaunal inverts.       0.029          <0.001  0.029 Sum 0.245 0.004 <0.001 0.011 0.207 0.005 0.001 0.029 0.003 0.025 0.221 0.025 0.232 <0.001 0.009 0.035 0.272 0.010 0.001 1.337  Table F3: 1900 Landings. Group Name Herring Hook and Line Salmon seine Eulachon Whaling Longline (setline) FN Halibut FN Inverts. Total Mysticetae     0.027    0.027 Odontocetae     0.002    0.002 Transient salmon  0.126      0.126 Coho salmon   0.012      0.012 Chinook salmon   0.019      0.019 Dogfish      0.017   0.017 Eulachon    0.043     0.043 Adult herring 0.002        0.002 Juvenile halibut  0.008     0.002  0.010 Adult halibut  0.008     0.002  0.010 Adult Pacific cod       0.001  0.001 Adult lingcod  0.003       0.003 Epifaunal inverts.       <0.001 <0.001 Infaunal invert. detrit.       <0.001 <0.001 Sum 0.002 0.018 0.156 0.043 0.030 0.017 0.005 <0.001 0.270  Table F4: 1750 Landings. Group Name Sea otters Halibut hook&line Salmon seine Eulachon Herring Whaling Cod, etc. Inverts. Total Sea otters <0.001        <0.001 Mysticetae      <0.001   <0.001 Seals, sea lions      <0.001   <0.001 Transient salmon  0.046      0.046 Coho salmon   0.023      0.023 Chinook salmon   0.023      0.023 Eulachon    0.043     0.043 Adult herring     0.002    0.002 Juvenile halibut  0.010       0.010 Adult halibut  0.010       0.010 Adult Pacific cod       0.001  0.001 Adult lingcod       <0.001  <0.001 Epifaunal invertebrates       <0.001 <0.001 Infaunal invert. detrit.       <0.001 <0.001 Sum <0.001 0.019 0.091 0.043 0.002 <0.001 0.002 0.001 0.159 Ecosystem Models of Northern BC, Past and Present, Page 40  APPENDIX G.     GROUP DEFINITIONS  Table G1. Species included in each model group. Name of Ecopath functional group is in bold. Common name Scientific name   Sea Otters  Sea otter Enhydra lutra     Mysticetae   blue whale Balaenoptera musculus fin whale Balaenoptera physalus sei whale Balaenoptera borealis humpback whale Megaptera novaeangliae right whale Balaena glacialis gray whale Eschrichtius robustus     Odontocetae  sperm whale Physeter macrocephalus Baird's beaked whale Berardius bairdii northern right whale dolphin Lissodelphis borealis Pacific white-sided dolphin Lagenorhynchus obliquidens Dall’s porpoise Phocoenoides dalli harbour porpoise Phocoena phocoena killer whale Orcinus orca     Seals and sea lions  Steller sea lion Eumetopias jubatus harbour seal Phoca vitulina northern fur seal Callorhinus ursinus northern elephant seal Mirounga angustirostris California sea lion Zalophus californianus     Seabirds   gulls  Laridae grebes  Podicipedidae Cassin’s auklet  Ptychoramphus aleuticus tufted puffin  Fratercula corniculata common murre  Uria aalge rhinoceros auklet Cerorhinca monocerata marbled murrelet  Brachyramphus marmoratus pigeon guillemot  Cepphus columba merganser spp.  Mergus serrator, M. merganser pelagic cormorants  Phalacrocorax pelagicus sooty shearwater  Puffinus griseus northern fulmar  Fulmarus glacialis double-crested cormorant Phalacrocorax auritus common loon  Gavia immer     Transient salmon  sockeye Oncorhynchus nerka chum Oncorhynchus keta pink salmon Oncorhynchus gorbuscha     Coho and chinook salmon  coho salmon Oncorhynchus kisutch chinook salmon Oncorhynchus tshawytscha     Juvenile and adult squid  common squid Loligo opalescens Ratfish   ratfish Hydrolagus collei     Dogfish  dogfish Squalus acanthias     Juvenile and adult pollock   walleye pollock Theragra chalcogramma     Forage fish and eulachon  sandlance Ammodytes hexapterus pilchards Sardinops sagax   anchovy Engraulis mordax   capelin Mallotus villosus   chub mackerel Scomber japonicus   shad  Alosa sapidissima   smelts  Osmeridae eulachon Thaleichthys pacificus     Juvenile and adult herring  Pacific herring Clupea pallasi     Juvenile and adult Pacific ocean perch Pacific Ocean perch Sebastes alutus     Inshore rockfish  copper rockfish Sebastes caurinus quillback rockfish Sebastes maliger tiger rockfish Sebastes nigrocinctus China rockfish Sebastes nebulosus yelloweye rockfish  Sebastes rubberrimus     Juvenile and adult piscivorous rockfish rougheye rockfish Sebastes aleutioanus shortraker rockfish Sebastes borealis shortspine thornyhead Sebastolobus altivelis  longspine thornyhead Sebastolobus alascanus black rockfish Sebastes melanops blue rockfish Sebastes mystinus chillipepper  Sebastes goodei dusky rockfish Sebastes ciliatus     Juvenile and adult planktivorous rockfish yellowmouth rockfish Sebastes reedi red-stripe rockfish Sebastes proriger widow rockfish Sebastes entomelas yellowtail rockfish Sebastes flavidus darkblotch rockfish Sebastes cremeri canary rockfish Sebastes pinniger Back to the Future on Canada’s West Coast, Page 41  splitnose rockfish Sebastes diploproa sharpchin rockfish Sebastes zacentrus Puget sound rockfish Sebastes emphaeus bocaccio  Sebastes paucispinis shortbelly rockfish Sebastes jordani     Juvenile and adult turbot  arrowtooth flounder Atheresthes stomias     Juvenile and adult flatfish  rock sole Lepidosetta bilineata English sole Parophyrys vetulus dover sole Microstomas pacificus     Juvenile and adult halibut  halibut Hippoglossus stenolepsis     Juvenile and adult Pacific cod Pacific cod Gadus macrocephalus     Juvenile and adult sablefish   Sablefish Anoplopoma fimbria     Juvenile and adult lingcod  lingcod Ophiodon elongatus     Shallow-water benthic fish  sculpins  Cottidae blennies  Blennidae poachers  Agonidae gobies  Gobiedae greenlings  Hexagramidae rock greenling Hexagrammos lagocephalus eelpouts Zoarcidae northern clingfish Gobiesox maeandricus   red irish lords Hemilepidotus hemilepidotus   cabezon Scorpaenichthys marmoratus   cutthroat trout  Oncorhynchus clarki clarki   white sturgeon Acipenser transmontanus       Skates  big skate  Raja binoculata longnose skate  Raja rhina starry skate  Raja stellulata black skate  Raja kincaidi deep-sea skate  Raja abyssicola tope shark Galeorhinus galeus   great white shark Carcharodon carcharias   broadnose sevengill shark Notorynchus cepedianus   bluntnose sixgill shark Hexanchus griseus   blue shark  Prionace glauca   basking shark  Cetorhinus maximus   diamond stingray  Dasyatis dipterura   Pelagic stingray Pteroplatytrygon violacea       Large and small crabs  Dungeness crab  Cancer magister red rock crab  Cancer productus tanner crab  Chionecetes sp. king crab  Paralithodes sp. kelp crab Pugettia producta     Commercial shrimp   smooth shrimp Pandalus jordani spiny shrimp Pandalus borealis eous pink shrimp Pandalus goniurus coonstripe shrimp Pandalus danae humpback shrimp Pandalus hypsinotus sidestripe shrimp Pandalopsis disbar prawn Pandalus platycterus     Macrophytes  bull kelp  Nereocystis leutkeana giant kelp Macrocystis integrifolia 

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