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Ecosystem models of Newfoundland for the time periods 1995, 1985, 1900 and 1450. Pitcher, Tony; Heymans, Johanna J. (Sheila); Vasconcellos, Marcelo 2002

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<@/?2=@2/!F2:1=2!G2/2;=-?!G2H.=1/!!0110'''2/345%'61'''7458%&''9'!!!!,-./0/123!4.526/!.7!$287.9:56;:5!<.=!>?2!>@32!A2=@.5/!%&&BC!%&'BC!%&DD!;:5!%EBD!!!!!!!!!!   !<@/?2=@2/!F2:1=2C!I:@J2=/@10!.7!K=@1@/?!F.693L@;C!F;:;5;!"##$!%%&'()*+*  ,FM#N#>,4!4MO,P#!M<!$,Q<MI$OPR$O!<MG!>S,!>"4,!A,G"MO#!!%&&BC!%&'BC!!%&DD!R$O!%EBD!               Edited by  Tony  J. Pitcher, Johanna J. (Sheila) Heymans  and Marcelo Vasconcellos      74 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 NEWFOUNDLAND FOR THE TIME PERIODS 1995, 1985, 1900 AND 1450  Edited By Tony J. Pitcher,  Johanna J. (Sheila) Heymans and Marcelo Vasconcellos  2002  Fisheries Centre Research Reports 10(5):  74 pages  CONTENTS Page Director?s Foreword: More Than One Route To Heaven ....................................................................... 3 Executive Summary..................................................................................................................................... 4 A Model of the Marine Ecosystem of Newfoundland and Southern Labrador (2J3KLNO) in the Time Periods 1985-1987 and 1995-1997  Johanna J. (Sheila) Heymans and Tony J. Pitcher  Model Description by Group........................................................................................................... 5   1) Walrus............................................................................................................................................5   2) Cetaceans.......................................................................................................................................6   3) Grey seals ......................................................................................................................................6   4) Harp seals......................................................................................................................................6   5) Hooded seals .................................................................................................................................7   6-8) Seabirds .................................................................................................................................... 8   Groundfish species ..........................................................................................................................10   9-10) Cod .........................................................................................................................................10   11-12) American plaice (adult and juvenile)...................................................................................10   13-14) Greenland halibut (adult and juvenile)...............................................................................10   15-17) Flounders ..............................................................................................................................10   18) Skates......................................................................................................................................... 11   19) Dogfish....................................................................................................................................... 11   20) Redfish ...................................................................................................................................... 11   21) Transient mackerel (> 29 cm) .................................................................................................. 11   22-23) Demersal and bentho-pelagic piscivores (adult and juvenile) .......................................... 12   24-25) Large demersal fish (adult and juvenile)............................................................................ 12   26) Other small demersals.............................................................................................................. 12   27) Lumpfish ................................................................................................................................... 12   28) Greenland cod........................................................................................................................... 12   29) Atlantic salmon......................................................................................................................... 13   30) Capelin ...................................................................................................................................... 13   31) Sandlance................................................................................................................................... 13   32) Arctic cod .................................................................................................................................. 13   33) Herring ...................................................................................................................................... 14   34) Transient pelagics ..................................................................................................................... 14   35) Small pelagics............................................................................................................................ 14   36) Mesopelagics............................................................................................................................. 14   37-38) Squid (shortfin and Arctic squid) ....................................................................................... 14   39-41) Large crustaceans (large crabs, small crabs, and lobster) ................................................. 15   42) Shrimp....................................................................................................................................... 15   43-46) Benthos................................................................................................................................ 16   47-48) Zooplankton ........................................................................................................................ 16   49) Phytoplankton........................................................................................................................... 16   50) Detritus ..................................................................................................................................... 16  Balancing the Models:  1995-1997 ................................................................................................. 17  Balancing the Models:  1985-1987 .................................................................................................21  Conclusions .................................................................................................................................... 24  Acknowledgements........................................................................................................................ 24  References ...................................................................................................................................... 24  Appendix A: Model groups and species in Newfoundland.......................................................... 28  Appendix B: Diet matrices ........................................................................................................... 30  Appendix C: Balanced model and diet matrix 1995-1997 ........................................................... 36  Appendix D: Balanced model and diet matrix 1985-1987...........................................................40   A Picasso-esque View of the Marine Ecosystem of Newfoundland and Southern Labrador: Models for the Time Periods 1450 and 1900  Johanna J. (Sheila) Heymans and Tony J. Pitcher  Introduction ................................................................................................................................... 44  Model Description by Group ......................................................................................................... 44   1) Walrus......................................................................................................................................... 44   2) Cetaceans.................................................................................................................................... 45   3-5) Seals ........................................................................................................................................ 46    3) Grey seals......................................................................................................................................... 46    4) Harp seals........................................................................................................................................ 46    5) Hooded seals ................................................................................................................................... 46    Seal catches.......................................................................................................................................... 47   6-8) Seabirds ...................................................................................................................................47   9-10) Cod ........................................................................................................................................ 48   11-12) American plaice ................................................................................................................... 49   13-14) Greenland halibut ............................................................................................................... 49   15-17) Flounders ............................................................................................................................. 50   18) Skates........................................................................................................................................ 50   19) Dogfish.......................................................................................................................................51   20) Redfish ......................................................................................................................................51   21) Transient mackerel (> 29 cm)...................................................................................................51   22-23) Demersal and bentho-pelagic piscivores (adult and juvenile) ..........................................51   24-25) Large demersals feeders (adult and juvenile) ....................................................................51   26) Other small demersals ............................................................................................................. 52   27) Lumpfish .................................................................................................................................. 52   28) Greenland cod.......................................................................................................................... 52   29) Atlantic salmon ........................................................................................................................ 52   30) Capelin ..................................................................................................................................... 53   31) Sandlance.................................................................................................................................. 53   32) Arctic cod.................................................................................................................................. 53   33) Herring ..................................................................................................................................... 53   34) Transient pelagics .................................................................................................................... 54   35) Small pelagics........................................................................................................................... 54   36) Mesopelagics ............................................................................................................................ 54   37-38) Squid (shortfin and Arctic squid) ...................................................................................... 54   39-41) Large crustaceans (large crabs, small crabs, and lobster) ................................................ 54   42) Shrimp.......................................................................................................................................55   43-46) Benthos ................................................................................................................................55   47-48) Large and small zooplankton..............................................................................................55   50) Detritus......................................................................................................................................55  Balancing the Models:  1900-1905................................................................................................ 55  Balancing the Models:  1450 ......................................................................................................... 57  Conclusions .................................................................................................................................... 58  Acknowledgements ........................................................................................................................ 59  References ...................................................................................................................................... 59  Appendix A: Model groups and species ? M and P/B estimates................................................64  Appendix B: Exports of salmon for Newfoundland ....................................................................66  Appendix C: Balanced model and diet matrix 1900-1905........................................................... 67  Appendix D: Balanced model and diet matrix 1450 .....................................................................71    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  74 pages ? Fisheries Centre, University of British Columbia, 2002  FISHERIES CENTRE RESEARCH REPORTS ARE ABSTRACTED IN THE FAO AQUATIC SCIENCES AND FISHERIES ABSTRACTS (ASFA) Page 3, Back to the Future on Canada?s East Coast  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 lots of those in 13th century Italy - and in a famous 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 is an example of this). St Antony?s uncompromising message was that you can only have one religion (i.e. his) if you wanted 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 Northern British Columbia, present four 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 Newfoundland, these times are 1995-97, representing a post cod-collapse ecosystem; 1985-87, before the cod collapse, 1900, before the major expansion of industrial fisheries and 1450, probably before Cabot and the Europeans arrived.  This material is the culmination of two 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 amount of archival and historical material has 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 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 Figure 1. St Antony of Padua Preaching to the Fishes At Rimini, a 3m-wide panel of azulejos, blue ceramic tiles (Moorish technology) for which thePortuguese are justly famous. The panel is located just behind the main door ofthe Church of St Antony in Alfama, an old Moorish district of Lisbon. StAntony?s skill as a Franciscan preacher is evident from the attentive deportmentof the fishes, compared to the unruly line of Italian heretics on the bridgebehind. Ecosystem Models of Newfoundland, Past and Present, Page 4  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. and 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.                      EXECUTIVE SUMMARY  Papers in this report set out the sources and derivations of parameters for four Ecopath mass-balance models covering Newfoundland and southern Labrador?s marine ecosystem (DFO statistical areas 2J3KLNO), referring to the historical times 1985, 1995, 1990 and 1450 (approximated as 3- to 5-year averages). The models have 50 compartments, including linked juvenile and adult life history stages for 6 groups of fish. The models include animals, such as walrus, that are locally extinct today. These models span a Newfoundland marine ecosystem that has changed greatly over the past 500 years. Anthropogenic changes were likely noticeable as soon as Basque whalers arrived, probably before 1450, while mass exploitation of seabirds in the 18th century resulted in extinction of the great auk. For several centuries cod fisheries were seemingly sustainable, but in the late 1980s they collapsed and have failed to recover. The precision of the models changes as we go back in time. While the 1990s and 1980s models, based on many recent scientific surveys and estimates, are likely a good approximation of the true ecosystem, the earlier models have an approximate date of reference, and are less certain, although a great deal of information from historical, archival and archaeological sources was incorporated. These static mass-balance models represent starting values for dynamic ecosystem simulations, which aim to determine sustainable and responsible fisheries that might be operated in ecosystems restored to these past states: part of ?Back to the Future? policy explorations.    Page 5, Back to the Future on Canada?s East Coast   A MODEL OF THE MARINE ECOSYSTEM OF NEWFOUNDLAND AND SOUTHERN LABRADOR (2J3KLNO) IN THE TIME PERIODS 1985-1987 AND 1995-1997  Johanna J. (Sheila) Heymans  and  Tony J. Pitcher Fisheries Centre, UBC   INTRODUCTION  The marine ecosystem of Newfoundland and southern Labrador has changed dramatically from the post World War II period, with the most noticeable change being from the late 1980s onwards. The collapse of groundfish species prior to the closure of the fishery in 1992 spawned a range of descriptions, explanations and theories regarding its origins (Bradbury et al. 2000, Hutchings and Myers 1995, Hutchings 1996, Myers and Cadigan 1995, Myers et al. 1997b, O'Driscoll et al. 2000, Rose et al. 2000, Shelton and Stansbury 2000 and Taggart et al. 1994). The reduction in the biomass of major species (cod and haddock) fundamentally changed groundfish community structure and reduced the total species biomass by 90% from the 1950s to the 1990s (Casey and Myers 2001). During this decrease in gadoid biomass on the southern Grand Bank, flatfish biomass increased and dominated from the late 1960s into the early 1980s. Biomass of Atlantic cod, haddock and white hake was greatest in the 1950s, with cod and haddock being equally abundant. Redfish biomass increased on the southern Grand Banks in the 1980s, but decreased overall since the 1950s (Casey and Myers 2001).   The objective of this paper is to derive parameters for mass-balance models of the marine ecosystem of Newfoundland and southern Labrador (DFO statistical areas 2J3KLNO) for two time periods: 1985-87 and 1995-97. The ecosystem was defined from the coast to the 1,000 m isobath and encompasses a total area of approximately 495,000 km2. These models will be used as historical starting points for dynamic policy explorations in  the ?Back to the Future? project (Pitcher 2001).   The models consist of 50 compartments: 48 consumers, one primary producer (phytoplankton), and one detritus group. A previous mass-balance model constructed for 1985-87 (Bundy et al. 2000) was used as a starting point for both new models, and was adapted by increasing the model compartments to include more linked juvenile-adult stages. These groups, and the representative species they include, are listed in Appendix A. In some cases groups are locally extinct (walrus and grey whales), but these compartments have been kept in the model (with very low biomass estimates) to facilitate comparison with historical models for 1900 and 1450 constructed by Heymans and Pitcher (this volume).  Summary information from earlier reports of workshops with local scientists (Pitcher et al. 2002) has been enhanced by further publications and advice from experts cited in the account for each group. In addition, much publicly available data from several sources (notably DFO, NAFO, FAO and ICES) has been taken from the Sea Around Us Project (SAUP) database (Watson et al. 2000).    MODEL DESCRIPTION BY GROUP  1) Walrus  In the past century only five walruses have been recorded in the area: two in 1949 and three in 1967 (Mercer 1967). In 1904 Ganong (1904) reported that they do not occur further south than Labrador and in 1951 Wright (1951) suggested that they are no longer found south of Hudson Strait. Thus, biomass in the 1980s and 1990s models was assumed to be very low (1*10-6tkm-2) in order to include these groups for comparison purposes. The P/B ratio of 6% was obtained from walruses in a Bering Sea mass-balance model (Trites et al. 1999). According to FAO (FAO 1978), adult walruses consume 45 kg of food per day, which gives a Q/B of 16.8 year-1. As the species was nearly extinct, they were not hunted off Newfoundland in the late twentieth century.  Walruses feed mostly on invertebrates that live in or on the bottom sediments (Anon. 2001a). Brenton (1979) suggests that 65 species of benthic invertebrates, principally mollusks, echinoderms, tunicates, crustaceans, priapulids and echiuroids are consumed. Allen (1942) reports that their diet occasionally includes seals and rarely fish. The diet of walruses in the Bering Sea model (Trites et al. 1999) was adapted as follows: consumption of small flatfish in the Bering Sea was assigned to juvenile American plaice; consumption of large flatfish was assigned to flounders; consumption of adult pollock was assigned to Greenland cod; consumption of juvenile pollock was assigned to demersal bentho-pelagic juveniles. Consumption of pelagics was assigned to capelin, and deepwater fish were broken down into other large demersals and seals (1% each for juvenile Ecosystem Models of Newfoundland, Past and Present, Page 6  demersals and other small demersal feeders, and 0.1% each for grey, harp and hooded seals). The benthic particulate feeders in the Bering Sea model included snow and tanner crabs, red and blue king crabs, and shrimp (Trites et al. 1999), and this was therefore redistributed to small crabs and shrimps (12% each). Infauna in the Bering Sea model consist of clams, polychaetes and other worms (mainly Echiuridae) (Trites et al. 1999). Thus the consumption of infauna in the Newfoundland model includes 10% polychaetes and 30% bivalves. Epifauna in the Bering Sea model include hermit crabs, snails, brittle stars, and starfish (Trites et al. 1999). In the Newfoundland model the consumption of epifauna was split between other benthic invertebrates (20%) and Echinoderms (5%) (Appendix B).   2) Cetaceans  The species of whales that are known to occur in the area include the humpback Megaptera novaeangliae, fin Balaenoptera physalus, minke Balaenoptera acutorostrata, sei Balaenoptera borealis, sperm Physeter catodon, pilot Globicephala melaena and blue whale Balaenoptera musculus (Bundy et al. 2000). The main porpoise species is the harbour porpoise Phocoena phocoena. Stenson et al. (2002) assumed that the biomass of whales in the 1990s was similar to that of 1985-1987 (0.251 tkm-2 as obtained from Bundy et al. 2000). The P/B and Q/B estimates for cetaceans given by Bundy et al. (2000) were used in both models. Almost no whales were killed by humans during 1985-1987, but a small catch was recorded by the grappling and wounding fishery (0.000058 tkm-2yr-1) in 1995-97 (see Table 7).   Diet estimates for cetaceans made by Bundy et al. (2000) were adapted for the new groupings as follows: the proportions of large and small demersals in the diet were broken down into 1.5% each for large and small bentho-pelagic and demersal fish, and 0.6% for lumpfish. Piscivorous and planktivorous pelagic feeders (small) were divided into small pelagics, herring, squid (5.4% each) and mesopelagics (3%) (Appendix B).  3) Grey seals  For the purposes of the Back to the Future project, it was assumed that there were some grey seals in the 2J3KLNO area prior to commercial sealing (Heymans and Pitcher, this volume). Therefore grey seals were added, although a very small biomass was assumed (1*10-6 tkm-2). The P/B ratio of 6% for seals in the Bering Sea model (Trites et al. 1999) was used for grey seals in all models. Dommasnes et al. (2001) and Trites et al. (1999) estimate a Q/B ratio for grey seals in the Norwegian and Bering Seas of 15.0 and 15.93 yr-1, respectively. We used 15.0 yr-1 as a Q/B ratio for grey seals in Newfoundland. Diets of grey seals (Appendix A) were adapted from diets for areas 4T, 4X and 3Ps obtained by Hammill and Stenson (2000). There were no catches of grey seals in 2J3KLNO in either time periods.   4) Harp seals  The biomass of harp seals in the 1980s was estimated at 0.184 tkm-2 (Bundy et al. 2000), and estimates for the 1990s were based on population size data obtained by Healey and Stenson (2000), Hammill and Stenson (2000) and Stenson and Sjare (1997). To estimate harp seal biomass in the model area it was assumed that 20% of all age groups remain in the Arctic throughout the year and that the residency period in Div. 2J and 3KL is from 21 November to 6 July (Stenson and Sjare 1997). One-third of the adult population and 20% of juveniles (ages 1?4) were assumed to enter the Gulf of St. Lawrence at or around the beginning of December and remain there until the end of May. A small proportion (5%) of the seals that migrated southward were assumed to remain in the study area for the entire year, with the proportion in each area the same as Table 1. Catch (numbers) of harp seals in the Gulf and Front region of Newfoundland and Labrador (Stenson, pers. comm.)  Age 1995 1996 1997 0 34106 184856 220476 1 6750 15052 17730 2 4898 10919 8126 3 4040 4133 2733 4 2995 3146 1920 5 3138 2757 1553 6 1950 2165 1255 7 1950 2067 1106 8 807 1376 739 9 570 981 516 10 332 1376 1330 11 475 1277 962 12 332 789 516 13 190 789 813 14 475 981 297 15 475 981 367 16 237 1474 516 17 285 1474 590 18 380 888 442 19 190 592 297 20 285 592 516 21 285 592 297 22 47 789 223 23 190 493 149 24 47 592 223 25+ 332 1771 516 Page 7, Back to the Future on Canada?s East Coast   for the winter period. The average weight of a harp seal is 100 kg (Hammill and Stenson 2000). Based on the above assumptions and on an average population of 5 million seals the biomass of harp seals in the 1990s is estimated at approximately 0.41 tkm-?.  The P/B and Q/B ratios of 0.102 and 17.412 yr-1, respectively, were obtained from Bundy et al. (2000). Diets of harp seals for 1985-87 and 1995-97 were obtained from Stenson (pers. comm.) and adapted to the groups in this model (Appendix B) by assuming that birds in the diet are mostly dovekies and murres (piscivorous birds). The flounders in the diet were assumed to be mainly witch flounder, and unknown fish was assumed to be yellowtail flounder, as it was a very small proportion of the total diet. Gadoid species (< 35 cm) was assumed to be Arctic cod, and Gadus species (? and > 35 cm) was divided between Atlantic cod and Greenland cod according to the ratio of their biomass estimates (Appendix B).  The catch of harp seals in the 1980s was estimated at around 0.001 tkm-2yr-1 (Bundy et al. 2000). Total harp seal catches for the 1995-97 period, in the Gulf and Front areas of Newfoundland and Labrador were obtained from Stenson (pers. comm., Table 1) and adapted for seals caught in 2J3KLNO by assuming that 76% of the 0 age group and 85% of 1+ seals in 1995 were caught in the Front region (obtained from the official catch statistics). In 1996 the proportion of seals caught on the Front was 62% and 86% respectively for 0 and 1+ seals, and in 1997 the proportions were 74% and 83% respectively. The percentage struck-and-lost is only 1% for the 0 group while in 1+ approximately 50% is lost.  Thus the total harp seal catch was approximately 3,320 tonnes juveniles (0 group) and 3,830 tonnes adults (1+), when using the average weight obtained from Hammill and Stenson (2000), with the total catch being approximately 7,150 tonnes or 0.014 tkm-2yr-1. There was also a very small catch (2*10-6 tkm-2yr-1) of harp seals in 1995-1997 by the grappling and wounding fishery (see Table 7). Of the six species found in Newfoundland (harp, hooded, grey, harbour, ringed and bearded seals) all are known to occur as bycatch in various types of fishing gear, including trawls, purse seines, gill nets, and hook and line (FAO, 1995 in Walsh et al. 2000). Harp seals are the most common bycatch species and are taken primarily by inshore monofilament gill nets set for cod, flounder and lumpfish (Walsh et al. 2000). Entrapped seals are usually dumped at sea or used locally for food (Lien et al. 1988). The number of beaters (pups) and 1+ (adult) harp seals caught as bycatch in the lumpfish fishery (Walsh et al. 2000) are given in Table 2. The total bycatch of harp seals was therefore 1,053 tonnes (0.002 tkm-2yr-1) and 1,348 tonnes (0.003  tkm-2yr-1) in the 1985-1987 and 1995-1997 models, respectively.  5) Hooded seals  There were approximately 600,000 hooded seals in the population in 1995 and 1996 (Hammill and Stenson 2000). Hooded seals have an average weight of 220 kg, and stay in the area for about half the year (Hammill and Stenson 2000). Half the population goes to the Gulf of St. Lawrence, which gives a 1990s biomass of approximately 0.062 tkm-?. The biomass of hooded seals in 1985-1987 was estimated at 0.034 tkm-? (Bundy et al. 2000). The P/B and Q/B ratios of 0.109 and 13.1 yr-1, respectively, obtained from Bundy et al. (2000) were used in both models. Diets were obtained from Hammill and Stenson (2000) and adapted for the groups in this model (Appendix B).  The catch of hooded seals in the 1980s was estimated at 0.00018 tkm-2yr-1 (Bundy et al. 2000), while the catch for 1995-97 was obtained from ICES/NAFO (Anon. 2001b). It was assumed that most of these catches (Table 3) were taken from 2J3KLNO and that approximately 25,000 of the hooded seals caught in 1996 were pups, while all the other seals caught in these 3 years were adults (Stenson pers. comm.). The average weights of juvenile and adult hooded seals (37.5 kg and 220 kg respectively) were obtained from Hammill and Stenson (2000). Thus the total catch of hooded seals in 1995-1997 was estimated at approximately 950 tonnes (Table 3), or 0.002 tkm-2yr-1. No data are available on Table 2. Bycatch of pups (= ?beaters?) and adult (1+)harp seals in the lumpfish fishery (Walsh et al. 2000) and Stenson (pers. comm.)  Year Pups (numbers) Adults (numbers) Pups (tonnes) Adults (tonnes) 1985 6047 3160 197 316 1986 11026 5725 358 573 1987 18559 11135 603 1113 Average   386 667 1995 5210 11736 169 1174 1996 8597 14803 279 1480 1997 12036 5495 391 549 Average   280 1068 Table 3. Number of hooded seals caught for 1995-1997 (ICES/NAFO, Anon. 2001b). *Available statistics not split by age. Year Pups 1+ Unknown Total 1995 0 0 857* 857 1996 0 0 25754* 25754 1997 0 7058 0 7058 Average 8333 2890   Tonnes 312 636   Ecosystem Models of Newfoundland, Past and Present, Page 8  bycatch of hooded seals although they are presumably not caught in large quantities.   6-8) Seabirds   In this model seabirds are partitioned into ducks, planktivorous and piscivorous birds. Ducks include the common eider, scoters and oldsquaws, while planktivorous birds include storm petrels and dovekies. Piscivorous birds include gannets, cormorants, gulls, kittiwakes, terns, guillemots, murres, razorbills and puffins (Burke et al. 2002). (The extinct great auk is included in historical models.) Fulmars and shearwaters (Brown et al. 1981) were at first placed with planktivorous birds, but Montevecchi (Memorial University of Newfoundland, pers. comm.) suggested that they should be grouped with piscivorous birds. The average annual biomass of breeding and wintering birds in 2J3KL for 2000 was 0btained from Burke et al. (2002) and the sum of these two values was used to calculate the biomass assuming that the biomass in 2J3KL and 2J3KLNO would be similar (Table 4). Bird biomass in the 1980s was estimated from average values obtained from Bundy et al. (2000), and also includes fulmars and shearwaters as piscivores. The P/B and Q/B ratios for birds given in Bundy et al. (2000) were used for all three of these groups.   The diet of seabirds used in Bundy et al. (2000) was adapted to the new groups (Appendix B) by using the large and small zooplankton for planktivorous birds, and dividing the mollusks in the diet of ducks between bivalves and other benthic invertebrates. Fish species eaten by piscivorous birds were divided as follows: small demersal feeders were partitioned into juvenile demersal feeders and juvenile bentho-pelagic piscivores, lumpfish and Greenland cod. Piscivorous small pelagic feeders were divided between small pelagics, mesopelagics and shortfin squid, while planktivorous small pelagic feeders were divided into herring, mesopelagics and Arctic squid. Large pelagic feeders were divided into salmon, transient pelagics and large transient mackerel. An extra source of food from fishery discards and offal probably have had significant positive effects on birds like the northern fulmar and several species of gulls (Tasker et al. 2000). This effect is not yet incorporated in the model, but may  be included at a later stage.  Anthropogenic mortality of seabirds includes hunting, bycatch, disturbance and oil pollution, which kill large numbers of ducks and other sea birds (Montevecchi and Tuck 1987). Approximately 500,000 thick billed and common murres are hunted annually (Montevecchi and Tuck 1987), although the hunting pressure decreased during the 1990s, when bag limits were imposed. Pursuit divers, such as auks and shearwaters, are the seabirds most commonly Table 5. Biomass estimates (tkm-2) of groundfish species obtained from Lilly (pers. comm.) without adjustments for catchability. Total catch (tkm-2yr-1) from Tables 6 and 7 and P/B (yr-1) calculated from mortality rates (Z = M + F) or from Q/B and gross conversion efficiency (see text for details). * biomass estimated assuming ecotrophic efficiency of 95%. Group Biomass 1985-87 Biomass 1995-97 Catch 1985-87 Catch 1995-97 Natural mortality P/B 1985-87 P/B 1995-97 Cod > 35 cm 1.8111 0.0799 0.5430 0.0011 0.104 0.404 0.118 Cod ? 35 cm 0.3018 0.0133 0.0000 0.0000 0.155 0.155 0.155 American plaice >35 cm 0.7215 0.3396 0.1021 0.0019 0.083 0.224 0.088 American plaice ?35 cm 0.5802 0.2731 0.0000 0.0000 0.124 0.124 0.124 Greenland halibut > 40 cm 0.3317 0.3657 0.0371 0.0260 0.026 0.138 0.098 Greenland halibut ? 40 cm 0.4739 0.5225 0.0000 0.0000 0.040 0.040 0.040 Yellowtail flounder 0.1784 0.3300 0.0387 0.0006 0.317 0.534 0.319 Witch flounder 0.0691 0.0243 0.0244 0.0028 0.235 0.588 0.348 Winter flounder * * 0.0026 0.0009 0.267 0.267 0.267 Skates 0.2347 0.2077 0.0300 0.0180 0.233 0.361 0.320 Dogfish 0.0073 0.0065 0.0003 0.0002 0.159 0.193 0.194 Redfish 0.4184 0.3799 0.1576 0.0133 0.113 0.489 0.148 Dem. & BP piscivores > 40 cm 0.0374 0.0152 0.0194 0.0016 0.098 0.617 0.206 Dem. & BP piscivores ? 40 cm * * 0.0000 0.0000 0.147 0.147 0.147 Large demersals > 30 cm 0.2366 0.1185 0.0276 0.0088 0.155 0.272 0.229 Large demersals ? 30 cm * * 0.0000 < 0.0001 0.232 0.232 0.232 Small demersals 0.0087 0.1190 0.0000 < 0.0001 0.564 0.564 0.564 Lumpfish 0.0129 0.0194 0.0000 < 0.0001 0.114 0.114 0.116 Greenland cod 0.0003 0.0001 < 0.0001 < 0.0001 0.101 0.166 0.594 Salmon * * 0.0019 0.0001 0.279 0.615 0.615 Table 4. Estimates of average seabird biomass (tkm-2) and catch (tkm-2yr-1) in 1980s and 1990s, with fulmars and shearwaters as piscivores. The average area for2J3KL is 367,542 km2 (Bundy, 2002). * from Bundy et al. (2000), t = tonnes.  Biomass  1990s Biomass 1980s* Catch   t tkm-2 tkm-2 tkm-2yr-1 Ducks 83 0.0002 0.0002 0.0001 Piscivores 4,945 0.0135 0.0010 0.0008 Planktivores  1,073 0.0029 0.0022 0.0002 Page 9, Back to the Future on Canada?s East Coast   caught as bycatch in gill nets, while loons, cormorants, puffins and gannets are also caught in high numbers (Montevecchi 2001). The common murre is the species most widely affected by fishing nets (Montevecchi 2001).   Seabirds vulnerable to longline fisheries include petrels, such as northern fulmars, shearwaters, gulls and skuas (Montevecchi 2001). Estimates of seabird bycatch from gill nets range from 0.25% in Atlantic puffins, to up to 20% in common murres, and virtually all other gear types also catch birds (Tasker et al. 2000). We assume that the 0.001 tkm-2yr-1 estimated as a catch by (Bundy et al. 2000) is divided into ducks, piscivorous and planktivorous birds in the ratio of Table 6. Catches (kgkm-2yr-1) of all species in the model area during 1985-1987 obtained from the SAUP database.   Bottom Trawls Midwater Trawls Mobile Seine Surround Nets Gill & Entangle Hooks and Lines Traps and Lift Nets Dredges Grappling  Wounding Other Gear Total Cod 385.580 0.701 0.560  56.071 37.169 62.787  0.088 542.956 American plaice 95.589 0.086 0.112  5.870 0.276 0.147 0.002 0.007 102.090 Greenland halibut 18.564 0.013   18.409 0.057 0.040  0.001 37.086 Yellowtail flounder 38.566 0.014 0.114   0.017   0.002 38.713 Witch flounder 23.208 0.228 0.017  0.935 0.006 0.002  0.002 24.400 Winter flounder 0.206    2.247 0.042 0.078   2.573 Skates 27.601 2.156   0.246 0.023 0.003   30.030 Dogfish 0.133 0.117        0.251 Redfish 125.189 31.960   0.428 0.001 0.001  0.001 157.579 Mackerel  0.040  15.886 1.385 0.007 0.636   17.956 BP piscivores 10.982 0.374 0.054  2.189 5.811 0.004  0.010 19.426 Large demersals 26.952 0.036 0.048  0.434 0.127 0.030  0.005 27.632 Greenland cod     0.005 0.013 0.002   0.020 Salmon     1.797 0.019 0.040   1.856 Capelin 0.024 44.123  18.483 0.008  35.720   98.358 Sandlance 0.083         0.083 Herring 0.010   11.084 4.314 0.002 0.487   15.898 Transient pelagics      0.708   0.007 0.715 Small pelagics 0.025 0.059   0.018 0.014 0.003   0.118 Shortfin squid 0.763 0.001    0.392 0.006   1.162 Large crabs     0.015  8.839   8.854 Lobster       1.382   1.382 Shrimp 2.345         2.345 Bivalves        0.233  0.233 Table 7. Catches (kgkm-2yr-1) of all species in the model area during 1995-1997 obtained from the SAUP database.   Bottom Trawls Midwater Trawls Mobile Seine Surround Nets Gill & Entangle  Hooks and Lines Traps and Lift Nets Dredges Grappling  Wounding Other Gear Total Cetaceans         0.058  0.058 Harp seals         0.002  0.002 Cod 0.174 0.002   0.711 0.187 0.078    1.152 American plaice 1.784 0.001   0.115 0.003     1.905 Greenland halibut 20.201    5.780 0.046    0.001 26.028 Yellowtail flounder 0.642     0.001     0.644 Witch flounder 2.742 0.001 0.001  0.011 0.001     2.755 Winter flounder     0.888  0.015    0.904 Skates 15.542    1.224 0.593   0.686  18.045 Dogfish 0.228          0.228 Redfish 11.502 1.792   0.023 0.028    0.001 13.346 Mackerel    0.002 0.013  0.001    0.017 BP piscivores 0.481    0.446 0.705     1.633 Large demersals 8.167    0.424 0.152 0.084    8.828 J demersals    0.002   0.001    0.003 Small demersals     0.028  0.003    0.030 Lumpfish       0.026    0.026 Greenland cod     0.006 0.036 0.001    0.043 Salmon     0.105 0.005 0.001    0.111 Capelin    12.475 0.010  11.520    24.005 Herring    5.343 1.603  0.040    6.987 Transient pelagics      0.955     0.956 Small pelagics 0.020    0.007 0.007 0.007  0.222  0.263 Mesopelagics     0.001   0.237 0.006  0.244 SF squid 0.003      0.230    0.233 Large crabs     0.017  65.248    65.265 Small crabs        0.044    0.044 Lobster       0.999    0.999 Shrimp 44.988       0.075   45.063 Bivalves     0.001   32.889  0.001 32.890 Other inverts       0.840 0.654  0.925 2.418 Ecosystem Models of Newfoundland, Past and Present, Page 10  their biomasses (Table 4). This was also used as an estimate of catch (and other anthropogenic mortality) in the 1990s.  Groundfish species  Biomass estimates for all groundfish species were obtained from G. Lilly (Department of Fisheries and Oceans, St. John?s, Newfoundland, pers. comm.), and were taken from Engels survey trawls for the 1980s and Campelen survey trawl estimates in the 1990s (Table 5). No catchability adjustments were made, as this information was not available at the time the models were constructed. Comparisons to subsequent models  that include catchability adjustments will be made later.   Diet estimates for groundfish species were obtained from Lilly (2002). Catches of all species were obtained from the SAUP database (Watson et al. 2000) (Tables 6 and 7).  9-10) Cod (adult and juvenile)  Bundy et al. (2000) estimated the (catchability adjusted) 1985-87 biomass of adult (> 35 cm) and juvenile cod at 2.04 tkm-2 and 0.34 tkm-2 respectively, and the unadjusted adult cod biomasses (Table 5) for both 1985-87 and 1995-97 were obtained from Lilly (pers. comm.). The ratio between adult and juvenile biomass obtained from Bundy et al. (2000) was used to estimate the biomass of juvenile cod at 0.3 tkm-2 and 0.013 tkm-2 respectively for 1985-87 and 1995-97 (Table 5). Q/B estimates calculated for the reconstruction of the 1900 model (Heymans and Pitcher, this volume) were in most cases much lower than those used in Bundy et al. (2000), probably due to the change in size structure of these species. Thus, the Q/B ratio obtained from Bundy et al. (2000) for Atlantic cod (3.24 yr-1 for adults and 6.09 yr-1 for juveniles) were used in the 1985-87 and 1995-97 models.  Bundy et al. (2000) estimated the annual P/B of adult and juvenile Atlantic cod to be 0.65 and 1.6 yr-1 respectively in the 1980s. Vasconcellos et al. (2002d) quotes Lilly as considering that the P/B of cod would have been higher in the mid-1980s than in the 1990s. Natural mortality is estimated at approximately 0.1 yr-1 (Appendix A Table A1 in Heymans and Pitcher, this volume). Fishing mortality is added to natural mortality to estimate P/B ratios for adult cod at 0.4 and 0.1 yr-1 for 1980s and 1990s respectively (Table 5). The P/B ratio of juvenile cod was assumed to be similar to the natural mortality (0.15 yr-1) for both models. Catches by fishing gears were obtained from the SAUP database (Tables 11 and 12). The diets of adult and juvenile cod (Appendix B) were obtained from Lilly (2002).  11-12) American plaice (adult and juvenile)  The biomass of adult American plaice (> 35 cm) (Table 5) for both 1985-87 and 1995-97 were obtained from Lilly (pers. comm.). The ratio between adult and juvenile biomass obtained from Bundy et al. (2000) was used to estimate the biomass of juvenile American plaice at 0.58 tkm-2 and 0.27 tkm-2 respectively for 1985-87 and 1995-97 (Table 5). The P/B ratio of adult American plaice was estimated from estimates of natural mortality (Appendix A Table A1 in Heymans and Pitcher, this volume) added to that of fishing mortality, to give P/B ratios of 0.22 and 0.08 yr-1 for 1980s and 1990s respectively (Table 5). The P/B ratio of juvenile American plaice was assumed to be similar to natural mortality (0.12 yr-1) for both models. The Q/B estimates obtained from Bundy et al. (2000) for American plaice (2.0 yr-1 for adults and 3.7 yr-1 for juveniles) were used in the 1985-87 and 1995-97 models. The diets of adult and juvenile American plaice (Appendix B) were obtained from Lilly (2002) and the catches (Tables 11 and 12) were obtained from the SAUP database.  13-14) Greenland halibut (adult and juvenile)  The biomass of adult (> 40 cm) Greenland halibut (= ?turbot?), for both 1985-87 and 1995-97 (Table 5) were obtained from Lilly (pers. comm.). The ratio between adult and juvenile biomass obtained from Bundy et al. (2000) was used to estimate the biomass of juvenile Greenland halibut as 0.47 tkm-2 and 0.52 tkm-2 respectively for 1985-87 and 1995-97 (Table 5). The P/B ratio of adult Greenland halibut was estimated from estimates of natural mortality (Appendix A Table A1 in Heymans and Pitcher, this volume) added to fishing mortality, to give P/B ratios of 0.14 and 0.10 yr-1 for 1980s and 1990s respectively (Table 5). The P/B ratio of juvenile American plaice was assumed to be similar to natural mortality (0.04 yr-1) for both models. The Q/B estimates obtained from Bundy et al. (2000), for Greenland halibut (1.5 yr-1 for adults and 4.5 yr-1 for juveniles) were used in the 1985-87 and 1995-97 models. The diets of adult and juvenile Greenland halibut (Appendix B) were obtained from Lilly (2002) and the catches (Tables 11 and 12) were obtained from the SAUP database.  15-17) Flounders  This group consists of yellowtail flounder Limanda ferruginea, witch flounder Glypto-Page 11, Back to the Future on Canada?s East Coast   cephalus cynoglossus and winter flounder Pseudopleuronectes americanus. Winter flounder is abundant from southern Labrador to Georgia, and is generally not found in depths exceeding 40 m (DFO, Anon. 1996a). Winter flounder is an opportunistic feeder that takes a variety of benthic organisms. They are caught in divisions 3K and 3L with gillnets as lobster bait and for food (DFO, Anon. 1996a). The biomass of yellowtail and witch flounder (Table 5) for 1985-87 and 1995-97 was obtained from Lilly (pers. comm.), while the biomass of winter flounder was estimated by assuming an ecotrophic efficiency of 95%. P/B ratios of yellowtail and witch flounder were based on estimates of natural mortality (Appendix A Table A1 in Heymans and Pitcher, this volume) added to that of fishing mortality. P/B ratios of 0.5 and 0.3 yr-1 were estimated for yellowtail flounder in the 1980s and 1990s respectively. Similarly, the P/B ratios of witch flounder were calculated at 0.6 and 0.3 yr-1 for the 1980s and 1990s respectively (Table 5). The P/B ratio of winter flounder was assumed to be similar to natural mortality (0.27 yr-1) for both models, as the species has been taken in small quantities for many years and no estimate of biomass was available to calculate fishing mortality.   The Q/B estimate (3.6 yr-1) of flounder obtained from Bundy et al. (2000) was used for yellowtail flounder in both the 1980s and 1990s models, as it was marginally larger than that calculated for the 1900 model (see Appendix A Table A2 in Heymans and Pitcher, this volume). The Q/B estimates calculated for witch (2.3 yr-1) and winter (1.6 yr-1) flounder in the 1900 model (see Appendix A Table A2 in Heymans and Pitcher, this volume) were used in both the 1985-87 and 1995-97 models. The diets of all three flounder species (Appendix B) were obtained from Lilly (2002) and the catches (Tables 11 and 12) were obtained from the SAUP database.  18) Skates  This group consists of barndoor skates Dipturus laevis, thorny skates Amblyraja radiata, smooth Malacoraja senta, little Leucoraja erinacea and winter skates Leucoraja ocellata. The biomass of skates (Table 5) for 1985-87 and 1995-97 was obtained from Lilly (pers. comm.). The P/B ratios of skates in the 1980s and 1990s were calculated from estimates of natural mortality (Appendix A Table A1 in Heymans and Pitcher, this volume) added to that of fishing mortality, to give P/B ratios of 0.36 and 0.32 yr-1 in the 1980s and 1990s respectively. The Q/B estimate (2.9 yr-1) of skates obtained from Bundy et al. (2000) was used in both the 1980s and 1990s models. The diet of skates (Appendix B) was obtained from Lilly (2002) and the catches (Tables 11 and 12) from the SAUP database.  19) Dogfish  Spiny dogfish Squalus acanthias was separated from the large pelagic feeders in Bundy et al. (2000). The biomass (Table 5) for 1985-87 and 1995-97 was obtained from Lilly (pers. comm.). The P/B ratio of dogfish in the 1980s and 1990s was calculated from estimates of natural mortality (Appendix A Table A1 in Heymans and Pitcher, this volume) added to that of fishing mortality, to give P/B ratios of 0.193 and 0.194 yr-1 in the 1980s and 1990s respectively. The Q/B estimate (4.8 yr-1) of dogfish in New England, obtained from Bundy et al. (2000), was used in both the 1980s and 1990s models. The diet of dogfish (Appendix B) was obtained from Lilly (2002) and the catches (Tables 11 and 12) from the SAUP database.  20) Redfish  The biomass of redfish (= Sebastes) for 1985-87 and 1995-97 (Table 5) was obtained from Lilly (pers. comm.). The P/B ratios in the 1980s and 1990s were calculated from estimates of natural mortality (Appendix A Table A1 in Heymans and Pitcher, this volume) added to that of fishing mortality, to give P/B ratios of 0.49 yr-1 and 0.15 yr-1 in the 1980s and 1990s respectively. The Q/B estimate (2.0 yr-1) of redfish obtained from Bundy et al. (2000) was used in both the 1980s and 1990s models. The diet of redfish (Appendix B) was obtained from Lilly (2002) and the catches (Tables 11 and 12) from the SAUP database.  21) Transient mackerel (> 29 cm)  The biomass of transient (= migratory) mackerel is not well studied. Bundy et al. (2000) suggest that the biomass of mackerel in 1985-87 was approximately 184,411 tonnes, or 0.37 tkm-2. However, no estimate of biomass for transient mackerel is available for 1995-97, and it is estimated by assuming an ecotrophic efficiency of 95%. The natural mortality of mackerel was calculated at 0.5 yr-1 (Appendix A Table A1 in Heymans and Pitcher, this volume), while the P/B ratio used in Bundy et al. (2000) was only 0.3 yr-1, as it took into account the residence time of the transients. The value obtained from Bundy et al. (2000) was used in both the 1985-87 and 1995-97 models. The Q/B ratio (4.4 yr-1) obtained from Bundy et al. (2000) for transient mackerel on Georges Bank was used in both models. The Ecosystem Models of Newfoundland, Past and Present, Page 12  diet of transient mackerel (Appendix B) was obtained from Lilly (2002) and the catches (Tables 11 and 12) from the SAUP database.  22-23) Demersal and bentho-pelagic piscivores (adult and juvenile)  The demersal and bentho-pelagic piscivores include white and silver hake (Urophycis tenuis and Merluccius bilinearis), monkfish Lophius americanus, sea ravens Hemitripterus americanus, cusk Brosme brosme and Atlantic halibut Hippoglossus hippoglossus. The biomass (Table 5) of adult (>40 cm) demersal and bentho-pelagic piscivores in 1985-87 and 1995-97 was obtained from Lilly (pers. comm.), while that of juveniles was estimated by assuming an ecotrophic efficiency of 95% for both models. The P/B ratios for adults in the 1980s and 1990s were calculated from estimates of natural mortality (Appendix A Table A1 in Heymans and Pitcher, this volume) added to that of fishing mortality, to give P/B ratios of 0.6 and 0.2 yr-1 in the 1980s and 1990s respectively. The P/B ratio for juveniles was assumed to be similar to that of natural mortality (0.15 yr-1) and was used for both models. The Q/B estimates calculated for adults (1.1 yr-1) and juveniles (1.7 yr-1) in the 1900 model (see Appendix A Table A2 in Heymans and Pitcher, this volume) were used in both the 1985-87 and 1995-97 models. The diets of both adults and juveniles (Appendix B) were obtained from Lilly (2002) and the catches (Tables 11 and 12) were obtained from the SAUP database.  24-25) Large demersal fish (adult and juvenile)  This group consists of a range of species that feed in the demersal domain, including haddock Melanogrammus aeglefinus, longfin Phycis chesteri and red hake Urophycis chuss, wolffish Anarhichas spp., grenadiers Coryphaenoides spp., eelpouts Lycodes spp. and batfishes. The biomass (Table 5) of adult (>40 cm) large demersals in 1985-87 and 1995-97 was obtained from Lilly (pers. comm.), while that of juveniles was estimated by assuming an ecotrophic efficiency of 95% for both models. The P/B ratios for adults in the 1980s and 1990s were calculated from estimates of natural mortality (Appendix A Table A1 in Heymans and Pitcher, this volume) added to that of fishing mortality, to give P/B ratios of 0.27 and 0.23 yr-1 in the 1980s and 1990s respectively. The P/B ratio for juveniles was assumed to be similar to that of natural mortality (0.23 yr-1) and was used for both models. The Q/B estimates calculated for adults (1.4 yr-1) and juveniles (2.1 yr-1) in the 1900 model (see Appendix A Table A2 in Heymans and Pitcher, this volume) were used in both the 1985-87 and 1995-97 models. The diets of both adults and juveniles (Appendix B) were obtained from Lilly (2002) and the catches (Tables 11 and 12) were obtained from the SAUP database.  26) Other small demersals  The other small demersals group consists of rocklings Enchelyopus spp., gunnel Pholis gunnellus, alligator fishes Ulcina olriki, Atlantic poachers Leptagonus decagonus, snake blennies Lumpenus lampretaeformis, seasnails and shannies Leptoclinus spp., sculpin Myoxocephalus spp., searobins Prionotus spp., eel blennies Anisarchus spp., wrymouth etc. The biomass (Table 5) of small demersals in 1985-87 and 1995-97 was obtained from Lilly (pers. comm.), although without catchability conversions these might be very low estimates. The P/B ratios for small demersals in the 1980s and 1990s were assumed to be similar to natural mortality (0.56 yr-1 from Appendix A Table A1 in Heymans and Pitcher, this volume). The Q/B estimate (4.47 yr-1) calculated for the 1900 model (see Appendix A Table A2 in Heymans and Pitcher, this volume) was used in both the 1985-87 and 1995-97 models. The diet of small demersals (Appendix B) was obtained from Lilly (2002) and the catches (Tables 11 and 12) were obtained from the SAUP database.  27) Lumpfish  Lumpfish are found in major concentrations on the St. Pierre bank off the southeast coast of Newfoundland (Garavis, 1985 in Walsh et al. 2000). They remain in deep offshore waters from late September to April and then migrate inshore during late April or early May to spawn (Stevenson and Baird 1988 in Walsh et al. 2000). The biomass (Table 5) of lumpfish in 1985-87 and 1995-97 was obtained from Lilly (pers. comm.). The P/B ratio for lumpfish in the 1980s and 1990s was calculated from estimates of natural mortality (Appendix A Table A1 in Heymans and Pitcher, this volume) added to that of fishing mortality, to give P/B ratios of 0.114 and 0.116 yr-1 in the 1980s and 1990s respectively. The Q/B estimate (1.4 yr-1) calculated for the 1900 model (see Appendix A Table A2 in Heymans and Pitcher, this volume) was used in both the 1985-87 and 1995-97 models. The diet of lumpfish (Appendix B) was obtained from Lilly (2002).    Lumpfish fishing started in 1968 and was conducted by inshore fishermen between April and July, using small vessels less than 35 feet Page 13, Back to the Future on Canada?s East Coast   long (Walsh et al. 2000). At present the fishery is mainly operated with gill nets while 20% have been longliners since the 1980s (Walsh et al. 2000). Lumpfish roe landings increased dramatically from 500 tonnes in 1985 to 3,000 tonnes in 1987 (Walsh et al. 2000), and varied between 1,000 and 2,300 tonnes in more recent years. South coast catches made up the greatest proportion of the catches in the 1980s (Walsh et al. 2000). Estimates of catch in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database.  28) Greenland cod  The biomass (Table 5) of Greenland cod in 1985-87 and 1995-97 was obtained from Lilly (pers. comm.). The P/B ratios in the 1980s and 1990s were calculated from estimates of natural mortality (Appendix A Table A1 in Heymans and Pitcher, this volume) added to that of fishing mortality, to give P/B ratios of 0.17 and 0.59 yr-1 in the 1980s and 1990s respectively. The Q/B estimate (1.3 yr-1) calculated for the 1900 model (see Appendix A Table A2 in Heymans and Pitcher, this volume) was used in both the 1985-87 and 1995-97 models. The diet of Greenland cod (Appendix B) was obtained from Lilly (2002) and estimates of catch in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database.  29) Atlantic salmon  No estimates of Atlantic salmon biomass were available for the 1985-87 or 1995-97 models, and it was estimated in both time periods by assuming an ecotrophic efficiency of 95%. The natural mortality of Atlantic salmon is calculated at 0.28 yr-1 (Appendix A Table A1 in Heymans and Pitcher, this volume). But with no estimate of fishing mortality, the P/B of Atlantic salmon (0.615 yr-1) was estimated by assuming a gross conversion efficiency of 0.15, and using the Q/B estimate (4.1 yr-1) calculated for the 1900 model (see Appendix A Table A2 in Heymans and Pitcher, this volume). The diet of Atlantic salmon (Appendix BAppendix B) was obtained from Lilly (2002) and estimates of catch in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database.  30) Capelin  The biomass of capelin in the 1980s model was estimated at 13 tkm-2 (Bundy et al. 2000). Anderson et al. (2001) estimated that the biomass of capelin in 2J3KLNO in the late 1990s was between 725,000 tonnes and 1,800,000 tonnes using catchabilities of 10% - 25% (Table 8). The lower catchability was used as it still estimates a very small biomass (3.7 tkm-2) for capelin. However, we used biomass estimates of 0.03 tkm-2 and 0.1 tkm-2 for 1985-87 and 1995-97 respectively, made by Lilly (pers. comm.), as none of the other biomass estimates that we have at present are adapted for catchability.  The P/B (1.15 yr-1) and Q/B (4.3 yr-1) estimates obtained from Bundy et al. (2000) were used in both models. However, when the catchability-adjusted biomass referred to in the previous paragraph was used to calculate F, P/B was subsequently calculated at approximately 0.59 yr-1 for both models. The diet of capelin (Appendix B) was obtained from Lilly (2002) and estimates of catch in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database.  31) Sandlance  The biomass of sandlance in 1985-87 (0.00007 tkm-2) and 1995-97 (0.2 tkm-2) was obtained from Lilly (pers. comm.). However, the Engels trawl that was used in the 1985-87 period substantially underestimated the biomass of sandlance. Therefore, as in Bundy et al. (2000), the biomass was assumed to be similar in the 1985-87 and 1995-97 periods. The P/B (0.62 yr-1) and Q/B (7.7 yr-1) estimates obtained from Bundy et al. (2000) were used in both models. The diet of sandlance (Appendix B) was obtained from Lilly (2002) and estimates of catch in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database.  32) Arctic cod  The biomass of Arctic cod in 1985-87 (0.006 tkm-2) and 1995-97 (0.14 tkm-2) was obtained from Lilly (pers. comm.). However, the Engels trawl that was used in the 1985-87 period substantially underestimated the biomass of Arctic cod, and it is suggested that the biomass (2.7 tkm-2) used in Bundy et al. (2000) should be used as the biomass of Arctic cod in 1985-87. The P/B (0.4 yr-1) and Q/B (2.6 yr-1) estimates obtained from Bundy et al. (2000) were used in both models. The diet of Arctic cod (Appendix B) Table 8. Biomass of capelin (from Anderson et al. 2001) estimated using three different catchability coefficients.  Year Q=0.14 Q=0.1 Q=0.25 1995 244,686 342,561 137,024 1996 941,267 1,317,774 527,109 1997 2,702,202 3,783,082 1,513,233 Average (tonnes) 1,296,052 1,814,472 725,789 Biomass (tkm-2) 2.6 3.7 1.5 Ecosystem Models of Newfoundland, Past and Present, Page 14  was obtained from Lilly (2002) and estimates of catch in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database.  33) Herring  The biomass of herring in the 1985-87 model was 235,000 tonnes, or 0.47 tkm-2 (Bundy et al. 2000). DFO (Anon. 2000) suggests that the biomass of mature herring (age 5+) for east and southeast Newfoundland decreased from 89,700 tonnes in 1998 to 83,100 tonnes in 2000. This gives an average biomass of 0.17 tkm-2, but it could be doubled to include the juveniles. A tentative value of 0.2 tkm-2 was used in the model for the 1990s. The P/B ratios for herring in the 1980s and 1990s were calculated from estimates of natural mortality (Appendix A Table A1 in Heymans and Pitcher, this volume) added to that of fishing mortality, to give P/B ratios of 0.54 yr-1 in both the 1980s and 1990s. The Q/B estimate (4.1 yr-1) calculated for the 1900 model (see Appendix A Table A2 in Heymans and Pitcher, this volume) was used in both the 1985-87 and 1995-97 models. The diet of herring (Appendix B) was obtained from Lilly (2002) and estimates of catch in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database.  34) Transient pelagics  Transient pelagics include bluefin tuna Thunnus thynnus, swordfish Xiphias gladius and sharks. Biomass for transient pelagics was estimated for both models by assuming an ecotrophic efficiency of 95%. The P/B (0.4 yr-1) and Q/B (3.3 yr-1) estimates obtained from Bundy et al. (2000) were used in both models. The estimates of catch in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database. The diet of transient pelagics (Appendix B) was not well known, and was adapted from Bundy et al. (2000) by assuming that the 0.2% cod was split into Atlantic and Greenland cod (0.1% each), and the small demersal feeders were divided into juvenile bentho-pelagic piscivores (1.2%), juvenile large demersal feeders (1.2%) and other small demersals (1.1%). Piscivorous and planktivorous pelagic feeders were divided into herring (11.5%), small pelagics (11.5%), small mesopelagics (11.5%) and shortfin and Arctic squid (5.6%).  35) Small pelagics  Small pelagics include shad Alosa sapidissima, butterfish Peprilus triacanthus, argentine Argentina silus, juvenile mackerel and Atlantic rainbow smelt Osmerus mordax mordax. Very little is known about these species, and the biomass was estimated for both models by assuming an ecotrophic efficiency of 95%. The P/B ratios for small pelagics in the 1980s and 1990s were assumed to be similar to estimates of natural mortality (Appendix A Table A1 in Heymans and Pitcher, this volume), to give a P/B ratio of 0.64 yr-1 in both the 1980s and 1990s. The Q/B estimate (5.3 yr-1) calculated for the 1900 model (see Appendix A Table A2 in Heymans and Pitcher, this volume) was used in both the 1985-87 and 1995-97 models. The diet of small pelagics (Appendix B) was obtained from Lilly (2002) and estimates of catch in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database.  36) Mesopelagics  Mesopelagic species in the 2J3KLNO area include laternfishes (Myctophidae), pearlsides Maur-olicus muelleri and barracudinas Paralepis elongata. Lilly (pers. comm.) calculates a biomass of 0.003 and 0.14 tkm-2 for the 1985-87 and 1995-97 models, respectively. However, this is probably grossly underestimating their biomass, as neither the Engels nor the Campelen sampling trawls catch mesopelagics effectively. Thus, their biomass was estimated for both models by assuming an ecotrophic efficiency of 95%. The P/B ratios for mesopelagics in the 1980s and 1990s were assumed to be similar to estimates of natural mortality (Appendix A Table A1 in Heymans and Pitcher, this volume), to give a P/B ratio of 1.4 yr-1 in both the 1980s and 1990s. The Q/B estimate (4.8 yr-1) calculated for the 1900 model (see Appendix A Table A2 in Heymans and Pitcher, this volume) was used in both the 1985-87 and 1995-97 models. The diet of mesopelagics (Appendix B) was obtained from Lilly (2002) and estimates of catch in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database.  37-38) Squid (shortfin and Arctic squid)  Two species of squid are present in the area: shortfin squid Illex illecebrosus and Arctic squid Gonatus spp. Very little is known about Arctic squid aside from the fact that they stay in the area throughout the year, while shortfin squid are highly migratory and spend only part of their time in the area (Bundy et al. 2000). The biomass of shortfin squid was probably very low during the 1985-1987 time-period. Bundy et al. (2000) and Vasconcellos et al. (2002c) suggested that large quantities of squid were last seen 20 years ago, and since 1982 the stock has remained small, indicating low productivity (Dawe et al. 2000). Page 15, Back to the Future on Canada?s East Coast   Thus the relative abundance of Illex sp. was assumed to be the same between 1985-1987 and 1995-1997 (Bundy 2002). However, no estimates of squid biomass are available for the 1980s model, so the biomasses of both shortfin and Arctic squid were estimated by assuming ecotrophic efficiencies of 95% for both species in all four models.   Bundy et al. (2000) estimated P/B ratios for planktivorous and piscivorous small pelagics of 0.5 and 0.6 yr-1, respectively, and used a gross efficiency of 0.15 to calculate their Q/B ratios. Thus, a P/B of 0.5 yr-1 was used for Arctic squid and 0.6 yr-1 for shortfin squid in all four models, with their Q/B ratios calculated by using a GE of 0.15. The diet of shortfin squid was taken from Appendix C Table 16 in Bundy et al. (2000) and it was assumed that the diet of Arctic squid consist of large and small zooplankton (Appendix B). Arctic squid are not fished in this system (Bundy et al. 2000) and estimates of shortfin squid catch in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database.   39-41) Large Crustaceans (large crabs, small crabs, and lobster)  The biomass estimates of large (> 95 mm carapace width) and small snow crabs (Table 9) for 1996-97 were obtained from Dawe et al. (2000), while in 1985-87 the biomass of large snow crabs was estimated at 86,345 tonnes or 0.17 tkm-2 (Bundy et al. 2000). No estimates were available for small crabs in the 1980s, and the biomass was left to be estimated by the model assuming an ecotrophic efficiency of 95%. These estimates were taken as the lower limit to the crab (> 95 mm and ? 95 mm) biomass. Bundy et al. (2000) estimated a biomass of 2,217 tonnes (0.005 tkm-2) for lobster in 1985-87 and no new estimate of lobster biomass was available for 1995-97. Therefore the biomass of lobster in the 1990s was left to be estimated by Ecopath assuming an ecotrophic efficiency of 95%. The P/B (0.4 yr-1) and Q/B (4.4 yr-1) estimates obtained from Bundy et al. (2000) for large crustaceans were used for all three compartments in both models. Estimates of catch for all three compartments in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database.  The diet of large and small crabs (Appendix B) were adapted from Lovrich and Sainte-Marie (1997) who suggested that large snow crabs feed on annelids, crustacean decapods and fish. Small snow crabs feed on amphipods and ophiuroids (Lovrich and Sainte-Marie 1997), while rock crabs feed on mussels, snails, brittlestars, amphipods and polychaetes (DFO 1996a) and toad crabs feed on amphipods, polychaetes, bivalves, ophiuroids, gastropods, chitons, sea urchins, small crabs and scavenge fish (DFO 1996b). The diet of lobster was assumed to be similar to that of large snow crabs (Appendix B).  Estimates of catch for all three compartments in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database. Discards of rock and toad crabs (Table 10) were obtained from Earl Dawe and Eric Way (pers. comm.).  42) Shrimp  Northern shrimp Pandalus borealis are fished from southern Davis Strait (0B) to the northeast Newfoundland Shelf (3K), while Pandalus montagui are fished commercially in areas 2, 3 and 4 (Parsons et al. 2000). The biomasses of these two species are distributed in the ratio of 9:1 (Parsons pers. comm.) and the average biomass of P. borealis from 1995-1997 was approximately 497,000 tonnes, or 1.0 tkm-2 (Table 11) which gives an overall biomass for all shrimp of 1.1 tkm-2 (Parsons et al. 2000). Bundy et al. (2000) estimated the biomass of shrimp in the 1980s to be 1.5 tkm-2, which is marginally larger than that of the 1990s. The P/B (1.45 yr-1) and Q/B (9.7 yr-1) estimates, as well as diet obtained from Bundy et al. (2000) for shrimp in 1985-87, were used in both models. Estimates of catch in 1985-87 and 1995-97 (Tables 11 and 12) were obtained from the SAUP database. Table 9. Biomass estimates of snow crab obtainedfrom (Dawe et al. 2000). Year Snow crab  > 95mm Snow crab (? 95 mm 1996 76,673 19,799 1997 100,726 26,876 Average (tonnes) 88,700 23,338 tkm-2 0.179 0.0471 Table 10. Estimates of rock and toad crabs discarded in 2J3KLNO.  Rock Crab (tonnes) Toad Crab (tonnes) Total Discards (tkm-2yr) 1995 26 352 0.000764 1996 0 0 0.000000 1997 13 17 0.000060 Average 13 123 0.000274 Table 11. Biomass of northern shrimp P. borealis and total shrimp obtained from Parsons et al. (2000), based on a 9:1 biomass ratio of P. borealis to P. montagui.  Year 3K 2HJ 3LNO Total 1995 267,000 ? 8,002  1996 501,300 90,480 26,694  1997 438,500 40,740 52,730  Average (tonnes) 402,267 65,610 29,142 497,019 Northern shrimp (tkm-2)    1.004 Total shrimp biomass (tkm-2)    1.104 Ecosystem Models of Newfoundland, Past and Present, Page 16  43-46) Benthos  The benthos of the Grand Banks include polychaetes, crustaceans, echinoderms and mollusks, and the undisturbed macrofauna are relatively homogenous (Kenchington et al. 2001). We divide benthos into echinoderms, polychaetes, bivalves and other benthic invertebrates. Kenchington et al. (2001) suggested that the biomass is dominated by propeller clams Cyrtodaria siliqua, and sand dollars Echinarachnius parma, while the polychaete Prionospio steenstrupi and the mollusk Macoma calcarea were the most abundant. The brittlestar Ophiura sarsi, the bivalve Macoma calcarea, and the sea urchin Strongylocentrotus palliddus also contributed substantially to the biomass (Kenchington et al. 2001). In general, Kenchington et al. (2001) found that the effect of trawling (otter trawling) on the infauna was limited and short term, especially on sandy bottoms where prominent bedforms were lacking. We therefore assume that the biomass of benthos would not have changed dramatically subsequent to the 1980s (Bundy et al. 2000). However, as no newer information on these groups is available, the biomass, P/B and Q/B ratios and diets of these groups were assumed to be similar in 1995-97 to 1985-87 (Bundy et al. 2000).  A directed fishery for Icelandic scallops started on the Grand Banks only in 1993, while they were caught in the Strait of Belle Isle and on St. Pierre Bank before that time (Anon. 1996b). They are mostly taken in areas 3LNO (Anon. 1996b). Estimates of catch of bivalves only in 1985-87 and bivalves and other invertebrates (probably sea-cucumbers) in 1995-97 (Tables 11 and 12) were obtained from the SAUP database.  47-48) Zooplankton  Zooplankton are divided into two groups, small and large zooplankton: large zooplankton are generally greater than 5 mm in length and include euphausiids, Chaetognaths, hyperiid amphipods, Cnidarians and Ctenophores (jellyfish), mysids, tunicates >5 mm and icthyoplankton (Bundy et al. 2000). The group includes herbivores (some euphausiid species), omnivores (most euphuasiids, hyperiid amphipods, mysiids and large tunicates) and carnivores (chaetognaths and jellyfish, Cnidarians and Ctenophores) (Bundy et al. 2000). Small zooplankton are generally smaller than or equal to 5 mm in length and include mainly copepods, with Calanus finmarchicus and Oithona similis being the most numerous. Other small plankton include tunicates <5 mm and meroplankton. C. fin-marchicus and O. similis are omnivorous.   Bundy et al. (2000) calculated the biomass of large zooplankton in 1996-1997 at 18.3 tkm-2 and in 1985-87 at 22.5 tkm-2. For small zooplankton in 1985-87, a value of 33.7 tkm-2 was used, while for 1995-97 the average seasonally adjusted biomass of 30.4 tkm-2 (Table 12) obtained from Bundy et al. (2000) was used. The P/B and Q/B ratios and diets obtained from Bundy et al. (2000) were used in both models and zooplankton were not caught in either time periods.  49) Phytoplankton  The biomass of phytoplankton in 1985-87 was estimated at 26.9 tkm-2 by Bundy et al. (2000), while in 1995-97 the average chlorophyll-a concentration (1.59 ?gl-1, or 0.12 tkm-2 over an average depth of 67 m) were obtained from the Ships of Opportunity and dedicated zonal monitoring cruises (Pepin, pers. comm.). The average C:Chl-a ratio of 43.9% used in Bundy et al. (2000) was used to calculate a phytoplankton biomass of 5.5 tCkm-2, while the C:wet weight ratio of 1:9 (Pauly and Christensen 1995) was used to calculate a biomass of 47.9 tkm-2wet weight in 1995-97. The P/B ratio of 93.1 yr-1 obtained from Bundy et al. (2000) was used in both models.  50) Detritus  The detritus pool was recalculated from the formula for detritus obtained from Pauly et al. (1993):   log10 D = -2.41 + 0.954 log10 PP + 0.863 log10 E  where D = detritus standing stock in gCm-2 (grams of carbon per square metre), PP = primary productivity in gCm-2yr-1 and E = euphotic depth (m).   A value of 54.7 m was used for the euphotic zone depth (Bundy et al. 2000), and a detritus pool of 412 tkm-2 was calculated, which is higher than the 389 tkm-2 calculated by Bundy et al. (2000) for 1985-87. However, if the estimate of primary production, or phytoplankton biomass, is Table 12. Small zooplankton biomass (tkm-2) estimates obtained from Bundy et al. (2000). Year Small zooplankton biomass Seasonally adjusted biomass 1995 16.3 23.4 1996 17.3 24.8 1997 30.o 42.9 Average 21.2 30.4 Page 17, Back to the Future on Canada?s East Coast   incorrect, this would change the detritus pool substantially.  BALANCING THE MODELS: 1995-1997  The unbalanced model of 1995-97 calculated large discrepancies with the ecotrophic efficiency of most of the fish species (Table 13). The biomass estimates of sandlance, Arctic cod and small mesopelagics were obviously too small, due to the lack of catchability adjustments. Therefore, their biomasses were estimated by assuming an ecotrophic efficiency of 95% each after adjusting the percentage they represented in the diet of other species.  Juvenile cod  The large ecotrophic efficiency of juvenile cod was probably due to the low P/B used in this model. The P/B estimate from Bundy et al. (2000) produced an ecotrophic efficiency of 39.7. To reduce the ecotrophic efficiency of juvenile cod, the percentages of juvenile cod in the diet of shortfin squid and juvenile bentho-pelagic piscivores were reduced to 0.01% each and in the diet of cetaceans and hooded seals it was reduced to 0.1%. The ecotrophic efficiency was still 6.4, and the only other predator taking large proportions of juvenile cod was the harp seal, the diet of which is more certain than the biomass estimate of juvenile cod. Thus, after these changes were made to the predators of juvenile cod, its biomass was estimated by assuming an ecotrophic efficiency of 0.95, giving a biomass of 0.09 tkm-2, which is similar to that of the biomass of large cod. With the reduction of large cod in the system, this possibility may be assumed.  Greenland cod  The ecotrophic efficiency of Greenland cod was estimated at ca. 333, and was mainly due to large dietary requirements of cetaceans, harp seals, piscivorous birds and adult cod. The percentage that Greenland cod contribute to their diets was reduced to 0.01%, and the diets recalculated. The diet of harp seals is very certain, but the arbitrary division made between Greenland cod and other cod might have overestimated Greenland cod in the diet of harp seals. However, after the diet adjustments were made the ecotrophic efficiency of Greenland cod was still 23. It was therefore decided to have the biomass estimated by assuming an ecotrophic efficiency of 95%, as the biomass of Greenland cod could be severely under-reported by having no catchability adjustment. Thus, the biomass of Greenland cod is estimated at 0.002 tkm-2.  Capelin  The ecotrophic efficiency of capelin was estimated at 80, and was mainly due to the high dietary requirements of cetaceans, harp seals, piscivorous birds, shortfin squid, juvenile bentho-pelagic piscivores and juvenile Greenland halibut.  !" Capelin was reduced to 1% in the diet of shortfin squid, and the percentage of small pelagics in the diet of shortfin squid increased to 25.9%, as they were probably part of the diet of squid.  !" Capelin was reduced to 10% and small pelagics were increased to 30% in the diet of cetaceans.  !" Capelin in the diet of juvenile Greenland halibut was reduced to 5%, and small pelagics were increased to 30%, and the diet of juvenile Greenland halibut was recalculated. !" Capelin in the diet of adult Greenland halibut was reduced to 10% and 20% of the diet was attributed to small pelagics. !" Capelin in the diet of both adult and juvenile cod was reduced to 10% and small pelagics were increased to 23%.  !" Capelin in the diet of juvenile American plaice was reduced to 10% and small pelagics were increased to 15%. !" In the diet of piscivorous birds, capelin was reduced to 10% and small pelagics and herring were increased to 20% each.  The ecotrophic efficiency of capelin was still 42.6 and the only two mortalities that were still a problem were harp seals and cetaceans. Thus, the biomass (4.4 tkm-2) was estimated by assuming Table 13. Model compartments that were unbalancedin 1995-97. # Group name Ecotrophic efficiency 10 Juvenile cod ? 40 cm 410.1217 28 Greenland cod 333.3397 30 Capelin 79.9645 16 Witch flounder 70.2847 40 Small crabs ? 95 cm 65.8388 36 Mesopelagics 36.6623 31 Sandlance 17.9046 22 Dem. ben-pel pisc. > 40 cm 14.7108 12 Juvenile Am. plaice ?35cm 12.7039 32 Arctic cod 11.3257 27 Lumpfish 8.8316 33 Herring 8.1190 20 Redfish 7.2716 9 Adult Cod > 40cm 6.6873 26 Other small demersals 6.4762 13 Adult G. halibut > 65cm 3.8546 19 Dogfish 2.9010 24 Large demersal fish > 30cm 2.8904 11 American plaice >35cm 2.5115 14 Juvenile G. halibut ? 65cm 1.8763 42 Shrimp 1.1377 Ecosystem Models of Newfoundland, Past and Present, Page 18  an ecotrophic efficiency of 95%, as the biomass estimates obtained from Lilly (pers. comm.) were not adjusted for catchability, and Anderson et al. (2001) estimates a biomass of 3.7 tkm-2.  Witch flounder  The ecotrophic efficiency of witch flounder was estimated at 70.3, and was mainly due to the high dietary requirements of harp and hooded seals. However, flounder in the diet of harp seals was taken to be all witch flounder, thus we reduced the amount of witch flounder in the diet to 2% and increased the winter flounder in the diet of harp seals to 4%, and recalculated the diet of harp seals. The percentage of witch flounder in the diet of hooded seals was also reduced to 0.1% and the diet recalculated. However, this still gave an ecotrophic efficiency of 18.8, and it was decided to estimate the biomass (0.48 tkm-2), as the biomass estimates were not adjusted for catchability, by assuming an ecotrophic efficiency of 95%.   Small crabs  The ecotrophic efficiency of small crabs was estimated at 65.8, which could be due to the fact that the P/B ratio of large crustaceans was used for small crabs. It was assumed that the P/B ratio of small crabs would probably be twice as large, which reduced the ecotrophic efficiency to 48.4. The predators that had the largest impact on small crabs were juvenile demersal fish, juvenile planktivorous fish, skates and small cod. The biomass (0.07 tkm-2) of small crabs was then estimated by assuming an ecotrophic efficiency of 95%.  The percentage of small crabs in the diet of adult and juvenile cod, adult and juvenile American plaice, adult and juvenile bentho-pelagic piscivores and adult demersal fish was reduced to 0.1%, while the percentage in the diet of skates was reduced to 0.5%. The percentage of small crabs in the diet of juvenile demersal fish was reduced to 0.01%, and all predator diets were recalculated to balance the small crab group.  Mesopelagics  Mesopelagic ecotrophic efficiency was 36.6 in the unbalanced system, and had risen to 70 with the changes made to the model thus far. However, the biomass estimate of mesopelagics was probably underestimated as no catchability adjustments were made. Thus, the biomass (2.04 tkm-2) was estimated by assuming an ecotrophic efficiency of 95%. This value is compatible with density estimates from a world review of mesopelagics (Gjosaeter and Kawaguchi 1980). When mapped into the Sea Around Us database of half-degree squares (R. Watson, pers. comm.), this source gives a mean biomass for 2J3KLNO of 1.1 tkm-2, with average offshore densities of 1.7 tkm-2.   Sandlance  Sandlance ecotrophic efficiency was estimated at 17.9, and had risen to 30.2 with the changes made to the model thus far. The main predators of sandlance were shortfin squid, juvenile bentho-pelagic piscivores, juvenile demersal fish, adult and juvenile American plaice, harp seals, cetaceans and adult and juvenile American plaice. The percentage of sandlance in the diet of shortfin squid was reduced to 1%, while in the diet of juvenile bentho-pelagic piscivores it was reduced to 0.5% and in the diet of juvenile demersal fish it was reduced to 0.1%. In the diet of adult and juvenile American plaice the percentages of sandlance were reduced to 10% each and in the diet of cetaceans the sandlance was reduced to 1%. All predator diets were recalculated, and the ecotrophic efficiency of sandlance was still 15.1. As the diet of harp seals was well established it was decided to estimate the biomass (3.6 tkm-2) of sandlance by assuming an ecotrophic efficiency of 95%.  Adult bentho-pelagic piscivores  The ecotrophic efficiency of adult bentho-pelagic piscivores was 14.7 in the unbalanced model, and 21.5 after the balancing of the above groups. The only predator of this species in the model is cetaceans, and we reduced the percentage it contributes to the diet of cetaceans to 0.1%, which calculates an ecotrophic efficiency of 1.5. The biomass was subsequently estimated by assuming an ecotrophic efficiency of 95% at 0.024 tkm-2, or double that given by the biomass estimates that were not adjusted for catchability.  Juvenile American plaice  The ecotrophic efficiency of juvenile American plaice was 12.7 in the unbalanced model, and had increased to 38.5 after the balancing of the previous groups. The P/B ratio of juvenile American plaice was assumed to be similar to their natural mortality (0.12 yr-1), but in the 1985-87 model (Bundy et al. 2000) it was estimated at 0.63 yr-1. It is assumed that the fishing mortality of juvenile American plaice was much reduced in 1995-97, but the P/B ratio was probably still higher than 0.1 yr-1, and a P/B of 0.4 yr-1 was assumed. The main predators of juvenile Page 19, Back to the Future on Canada?s East Coast   American plaice were harp seals and juvenile bentho-pelagic piscivores, and the juvenile plaice in the diet of juvenile bentho-pelagic piscivores was reduced to 0.1% to give an ecotrophic efficiency of 2.6. The biomass of juvenile American plaice (0.8 tkm-2) was then estimated by assuming an ecotrophic efficiency of 95% to take into consideration the lack of catchability adjustment in the biomass estimates.  At this stage, it was found that the cannibalism in juvenile bentho-pelagic piscivores was driving the ecotrophic efficiency of all other unbalanced compartments higher, while it caused previously balanced compartments to become unbalanced. The cannibalism in this group was therefore reduced to 0.01%.  Arctic cod  Arctic cod had an ecotrophic efficiency of 11.3, when using the P/B obtained from Bundy et al. (2000). However, using the natural mortality (0.57 yr-1) calculated for the 1900 model (Heymans this volume, Appendix A, Table A1), reduced the ecotrophic efficiency. The main predators of Arctic cod were harp seals and juvenile Greenland halibut. The percentage of Arctic cod in the diet of Greenland halibut was reduced to 0.1%, which reduces the ecotrophic efficiency to 7.7. As the diet of harp seals is relatively well known, and catchability was not included in the biomass estimates, the biomass (1.1 tkm-2) is estimated by assuming an ecotrophic efficiency of 95%.  Lumpfish  The ecotrophic efficiency of lumpfish was estimated at 8.8 in the unbalanced model, and increased to 14.5 after balancing the previous groups. Their main predators are cetaceans and piscivorous birds, and the percentage that lumpfish contribute to both their diets was reduced to 0.1%, which reduced the ecotrophic efficiency to 1.7. The biomass (0.034 tkm-2) was subsequently estimated by assuming an ecotrophic efficiency of 95%.  Herring  The ecotrophic efficiency of herring was estimated at 8.1 in the unbalanced model, and increased to 11.5 after balancing the previous groups. The main predators of herring are cetaceans and harp seals, and the percentage of herring in the diet of cetaceans was reduced to 0.1%, which reduced the ecotrophic efficiency of herring to 9.6. The biomass of herring was then estimated at 2.2 tkm-2 assuming an ecotrophic efficiency of 95% (an order of magnitude higher than estimated by DFO (Anon. 2000).  Redfish  The ecotrophic efficiency of redfish was estimated at 7.3 in the unbalanced model, and increased to 8.0 after balancing the previous groups. The main predators of redfish are juvenile demersal fish, juvenile Greenland halibut, skates and hooded seals. The percentages of redfish in the diet of juvenile Greenland halibut and skates were reduced to 5% each, while the percentage in the diet of juvenile demersal fish was reduced to 0.1% and the percentage in the diet of hooded seals was reduced to 1%. The biomass was then estimated by assuming an ecotrophic efficiency of 95% at 0.99 tkm-2, which more than doubles the 0.37 tkm-2 estimated by the Campelen trawl survey (unadjusted for catchability).  Adult cod  The ecotrophic efficiency of adult cod was estimated at 6.7 in the unbalanced model, and increased to 7.0 after balancing the previous groups. The main predators of adult cod are harp and hooded seals. Reducing the percentage of adult cod in the diet of hooded seals to 0.1% reduced the ecotrophic efficiency to 5.5. The P/B ratio used for adult cod (0.11 yr-1) in the 1995-97 model was much lower than the 0.65 yr-1 estimated by Bundy et al (2000). It was assumed that the P/B ratio was higher than that estimated by adding natural mortality to fishing mortality, and a value of 0.3 yr-1 was used, which reduced the ecotrophic efficiency to 2.2. The biomass of adult cod was then estimated at 0.18 tkm-2 by assuming an ecotrophic efficiency of 95%.  Other small demersals  The ecotrophic efficiency of small demersals was estimated at 6.5 in the unbalanced model, and increased to 9.0 after balancing the previous groups. The main predators of small demersals include juvenile bentho-pelagic piscivores, winter flounder, juvenile Greenland halibut, juvenile American plaice and harp seals. The percentage of small demersals in the diets of all these species (except for harp seal) was reduced to 0.5%. The biomass was then estimated at 0.5 tkm-2 by assuming an ecotrophic efficiency of 95%.  Adult Greenland halibut  The ecotrophic efficiency of adult Greenland halibut was estimated at 3.8 in the unbalanced Ecosystem Models of Newfoundland, Past and Present, Page 20  model, and increased to 4.5 after balancing the previous groups. The main predators of adult Greenland halibut are harp and hooded seals, and the percentage of this group in the diet of hooded seals was reduced to 1%, which decreased the ecotrophic efficiency to 2.0. The biomass (0.77 tkm-2) was then estimated by assuming an ecotrophic efficiency of 95%.  Dogfish  The ecotrophic efficiency of dogfish was estimated at 2.9 in the unbalanced model, and increased to 4.2 after balancing the previous groups. The main predators of dogfish are cetaceans, and reducing the percentage of dogfish in the diet of cetaceans to 0.1% reduced the ecotrophic efficiency to 2.5. The biomass was then calculated at 0.02 tkm-2 by assuming an ecotrophic efficiency of 95%.  Large demersal fish  The ecotrophic efficiency of large demersal fish was estimated at 2.9 in the unbalanced model, and increased to 4.4 after balancing the previous groups. The main predators of large demersal fish are cetaceans, and the percentage of large demersal fish in the diet of cetaceans was reduced to 0.1%, which reduced the ecotrophic efficiency to 1.8. The biomass was then estimated at 0.23 tkm-2 by assuming an ecotrophic efficiency of 95%, which is double the biomass estimated from the Campelen trawl (unadjusted for catchability).  Adult American plaice  The ecotrophic efficiency of adult American plaice was estimated at 2.5 in the unbalanced model, and increased to 2.6 after balancing the previous groups. The main predators of adult American plaice are harp seals. As the diet of harp seals is well studied, the biomass was re-estimated at 0.9 tkm-2, by assuming an ecotrophic efficiency of 95%.  Juvenile Greenland halibut  The ecotrophic efficiency of juvenile Greenland halibut was estimated at 1.9 in the unbalanced model, and increased to 2.8 after balancing the previous groups. The main predators of juvenile Greenland halibut are hooded seals, and reducing the percentage of juvenile Greenland halibut in the diet of hooded seals to 10% reduced the ecotrophic efficiency to 1.7. The biomass was then calculated at 1.0 tkm-2 by assuming an ecotrophic efficiency of 95%. Shrimp  The ecotrophic efficiency of shrimp was estimated at 1.1 in the unbalanced model, and increased to 2.0 after balancing the previous groups. The main predators of shrimp are juvenile Greenland halibut and juvenile demersal fish, and by reducing the percentage of shrimp in their diets to 1%, the ecotrophic efficiency of shrimp was reduced to 0.9.  Large zooplankton  After balancing the previous compartments the ecotrophic efficiency of large zooplankton was 1.7. The main predators of large zooplankton are small pelagic fish, mesopelagics, Arctic squid and cannibals. Cannibalism was reduced to 1%, with the percentage of small zooplankton in the diet of large zooplankton decreasing to 30% and phytoplankton increasing to 59%. The percentage of large zooplankton in the diet of small pelagic fish was reduced to 60%, while its contribution to the diet of Arctic squid and mesopelagics was reduced to 30% each. The percentage of large zooplankton in the diet of shortfin squid was reduced to 25%, and in the diet of herring it was reduced to 0.45% This still calculated an ecotrophic efficiency of 1.3, and the biomass of large zooplankton was then estimated at 25.4 tkm-2 by assuming an ecotrophic efficiency of 95%.  Final changes to the model in balancing  We opted to balance the model from the top-down, i.e., making the biomass of prey match the demand of predators by setting EE to 0.95. The alternative method (bottom-up) would be to reduce the predation pressure by decreasing the biomass or consumption rates of predators so that the total consumption matches the production of preys. One obvious consequence of using a top-down balancing is the tendency to estimate lower Fs using the ratio between catches and the new (increased) biomasses. To see which balancing method is the better assumption, the Fs estimated by Ecopath for the 1990s could be compared to the Fs estimated by DFO for the key demersal species (cod, American plaice, Greenland halibut, Greenland cod, redfish and witch flounder). [This will be done at a later stage, ED.]  Subsequent to the balancing of this model, changes were made to the bird compartments as given by Burke et al. (2002). These changes were the inclusion of fulmars and shearwaters into the piscivorous birds compartment (Montevecchi, Page 21, Back to the Future on Canada?s East Coast   Memorial University of Newfoundland, pers. comm.), and the addition of the wintering and breeding birds vs. taking the average of the two groups.   Additional information on recreational catches (Table 14) became available from the 1985 and 1995 surveys of recreational fishing in Canada (Robyn Forrest, Fisheries Centre, UBC pers. comm.1).  Finally, the predators of three other species were also expanded, as they were under-represented in the model: i. The predators of salmon were expanded to include cetaceans, grey seals, piscivorous birds, skates and transient pelagics.  ii. The predators of large crabs were expanded to include grey, harp and hooded seals as well as large cod. iii. The predators of lobster were expanded to include walrus, large cod, skates, large demersal piscivores and other large demersal species.   The new biomass estimates were put into the previously balanced model, and the new balanced model parameters given in Appendix C.    BALANCING THE MODELS: 1985-1987  The unbalanced model of 1985-87 calculated large discrepancies with the ecotrophic efficiency of most of the fish species (Table 15). The estimates of sandlance, Arctic cod and small mesopelagics, capelin and Greenland cod were obviously too small, due to the lack of catchability adjustments, so their biomasses were estimated by assuming an ecotrophic efficiency of 95% each after adjusting the percentage that they contribute to their predators.  Sandlance  The ecotrophic efficiency of sandlance was estimated at 30,412. The fishing mortality rate of 1.17 yr-1 indicates that the biomass of sandlance                                                   1 http://www.dfo-mpo.gc.ca/communic/statistics/recfsh95/content3.htm. http://www.dfo-mpo.gc.ca/communic/statistics/Historic/RECFISH/Index_85.htm was unrealistically small. The biomass of sandlance, calculated by Lilly (pers. comm.) was not adjusted for catchability, and therefore it was estimated (2.26 tkm-2) by assuming an ecotrophic efficiency of 95%. This estimate of sandlance biomass is comparable to the 2.7 tkm-2 estimated by Bundy et al. (2000).  Mesopelagics  Similar to sandlance, the biomass of mesopelagics was not adjusted for catchability, and the large ecotrophic efficiency (1463) calculated for mesopelagics indicates that the biomass was heavily underestimated. The biomass estimated by Lilly (pers. comm.) was 0.0003 tkm-2, but Ecopath estimated a value of 1.16 tkm-2 when taking into consideration the predator requirements in the ecosystem using an ecotrophic efficiency of 95%. This value is compatible with density estimates ftom a world review of mesopelagics (Gjosaeter and Kawaguchi 1980). When mapped into the Sea Around Us database of half-degree squares (R. Watson, pers. comm.), this source gives a mean biomass for 2J3KLNO of 1.1 tkm-2 with average offshore densities of 1.7 tkm-2.  Capelin  The ecotrophic efficiency of capelin was calculated at 397, and the fishing mortality was estimated at 3.5 yr-1, which indicates the underestimation of capelin biomass. The biomass of capelin was therefore estimated by assuming an ecotrophic efficiency of 95%, which estimated a biomass of 11.5 tkm-2, similar to the 13 tkm-2 estimated by Bundy et al. (2000) on which this model is based.    Table 14. Recreational catches (t/km-2yr-1) in Newfoundland and Labrador for 1985 and 1995. Species 1985 1995 Salmon 0.0017 0.0005 Cod 0.0082 0.1920 Mackerel 0.0003 0.2670 Smelts (small pelagics) 0.0016 0.0010 Tomcod (small demersals)  0.000007 Table 15. Model compartments that were unbalanced in 1985-87. # Group name Ecotrophic efficiency 31 Sand lance 30411.81 36 Mesopelagics 1462.53 30 Capelin 396.67 32 Arctic cod 363.52 28 Greenland cod 257.73 26 Other small demersals 86.17 14 G.halibut<=40cm 15.87 10 Cod <= 35 cm 15.04 27 Lumpfish 14.56 16 Witch flounder 7.45 12 Am. plaice<=35cm 5.34 20 Redfish 2.90 22 Large Dem. BP 2.76 19 Dogfish 2.61 13 G.halibut>40cm 2.25 33 Herring 1.87 24 L.dem. feeders 1.53 42 Shrimp 1.13 Ecosystem Models of Newfoundland, Past and Present, Page 22  Arctic cod  Arctic cod ecotrophic efficiency was estimated at 363, and the biomass was estimated at 2.23 tkm-2 by assuming an ecotrophic efficiency of 95%, which is comparable to the 3.0 tkm-2 estimated by Bundy et al. (2000).  Greenland cod  Greenland cod ecotrophic efficiency was estimated at 258, and the biomass was estimated at 0.1 tkm-2 by assuming an ecotrophic efficiency of 95%.  Other small demersals  Small demersal ecotrophic efficiency was estimated at 86, and the biomass was estimated at 0.9 tkm-2 by assuming an ecotrophic efficiency of 95%.  Juvenile cod  Juvenile cod ecotrophic efficiency was estimated at 15.04, and if the biomass was calculated by assuming an ecotrophic efficiency of 95%, the biomass of juvenile cod would have to be 7.6 tkm-2. This value is not realistic, and parameters of juvenile cod were examined. Bundy et al (2000) estimates a P/B of juvenile cod of 1.6 yr-1, which is an order of magnitude larger than the 0.115 yr-1 calculated by assuming that P/B = Z = F + M. As the calculation of F is dependent on the biomass, which is uncertain as discards are not well known, the 1.6 yr-1 calculated by Bundy et al. (2000) was used, calculating an ecotrophic efficiency of 0.8.  Juvenile Greenland halibut  Juvenile Greenland halibut ecotrophic efficiency was estimated at 15.8, and if the biomass was calculated by assuming an ecotrophic efficiency of 95%, the biomass would have to be 22.0 tkm-2. This value is not realistic, and parameters of juvenile Greenland halibut were examined. Bundy et al (2000) estimated a P/B of 0.87 yr-1, which is an order of magnitude larger than the 0.04 yr-1 calculated by assuming that P/B = Z = F + M. As the calculation of F is dependent on the biomass, which is uncertain as discards are not well known, the 0.87 yr-1 calculated by Bundy et al (2000) was used, leading to an estimated ecotrophic efficiency of 0.7.     Lumpfish, adult bentho-pelagic piscivores and adult demersal feeders  Lumpfish ecotrophic efficiency was estimated at 14.6, and the biomass is calculated at 0.23 tkm-2 if an ecotrophic efficiency of 95% is assumed. Lumpfish, Greenland cod, adult bentho-pelagic piscivores and large demersal fish were all combined in the large demersal feeders group in Bundy et al (2000), thus the sum of the biomass of lumpfish (0.23 tkm-2), Greenland cod (0.1 tkm-2), adult bentho-pelagic piscivores (0.04 tkm-2) and adult demersal feeders (0.24 tkm-2) is still less than the 0.85 tkm-2 estimated by Bundy et al (2000).   The ecotrophic efficiency of adult bentho-pelagic piscivores was calculated at 2.8, and estimating their biomass by assuming an ecotrophic efficiency of 95% gives a biomass of 0.12 tkm-2, which, added to the biomass of adult demersal feeders, Greenland cod and lumpfish, approaches the 0.85 tkm-2 of large demersal estimated by Bundy et al (2000). Similarly, the ecotrophic efficiency of adult demersal feeders was calculated at 1.5, and assuming an ecotrophic efficiency of 95%, calculates a biomass of 0.4 tkm-2, which, added to the 0.23 tkm-2 of lumpfish, 0.1 tkm-2 of Greenland cod and 0.12 tkm-2 of adult bentho-pelagic piscivores, approaches the 0.85 tkm-2 estimated by Bundy et al (2000).  Juvenile American plaice  The ecotrophic efficiency of juvenile American plaice was calculated at 5.3, and assuming an ecotrophic efficiency of 95% calculates a biomass of 8.8 tkm-2, which is an order of magnitude higher than the 0.8 tkm-2 calculated by Bundy et al (2000). Bundy et al (2000) estimates a P/B of 0.63 yr-1, which is three times larger than the 0.12 yr-1 calculated by assuming that P/B = Z = F + M. As the calculation of F is dependent on the biomass, which is uncertain as discards are not well known, the 0.63 yr-1 calculated by Bundy et al (2000) was used, calculating a biomass of 0.77 tkm-2. This value is similar to the 0.78 tkm-2 calculated by Bundy et al (2000), but larger than the 0.72 tkm-2 estimated for adult American plaice, which were obtained from Lilly (pers. comm.) and not adjusted for catchability yet.  Redfish  Lilly (pers. comm.) estimated redfish biomass (not adjusted for catchability) at 0.4 tkm-2, which is much lower than the biomass of 1.88 tkm-2 estimated by Bundy et al (2000), and which calculates an ecotrophic efficiency of 2.9. Page 23, Back to the Future on Canada?s East Coast   Assuming an ecotrophic efficiency of 95% calculates a biomass of 1.4 tkm-2, which is closer to that estimated by Bundy et al (2000).  Herring  The ecotrophic efficiency of herring was calculated at 1.87, and assuming an ecotrophic efficiency of 95% calculates a biomass of herring of 1.24 tkm-2, which is nearly three times the (catchability unadjusted) biomass estimated by Lilly (pers. comm.). However, the biomass of herring, mackerel, squid, small pelagics and mesopelagics (as calculated by Ecopath) sums to 4.6 tkm-2, which is lower than the 5.1 tkm-2 estimated by Bundy et al (2000) for small piscivorous and planktivorous feeders.  Dogfish  Dogfish ecotrophic efficiency was calculated at 2.6, using the biomass estimate (unadjusted for catchability) obtained from Lilly (pers. comm.). Assuming an ecotrophic efficiency of 95% estimates a biomass of 0.018 tkm-2. Dogfish, together with other sharks, tuna, swordfish and Atlantic salmon, were classified as large pelagic feeders by Bundy et al (2000), with a biomass of 0.03 tkm-2, which is similar to their sum total in this model.  Adult Greenland halibut  The ecotrophic efficiency of Adult Greenland halibut was calculated at 2.25 when using the biomass estimate (unadjusted for catchability) obtained from Lilly (pers. comm.). Conversely, assuming an ecotrophic efficiency of 95% calculates a biomass of 0.78 tkm-2, which is higher than the biomass estimated for juvenile Greenland halibut, and higher than the biomass estimated for adult Greenland halibut in Bundy et al (2000).   Bundy et al (2000) estimated a P/B of 0.3 yr-1, which is double the 0.14 yr-1 calculated by assuming P/B = Z = F + M. Since the calculation of F is dependent on the biomass, which is uncertain as discards and catchability are not well known, the 0.3 yr-1 calculated by Bundy et al (2000) was used, calculating an ecotrophic efficiency of 1.04. Subsequently, the biomass of adult Greenland halibut was estimated (0.36 tkm-2) by assuming an ecotrophic efficiency of 95%.  Witch and yellowtail flounders  The ecotrophic efficiency of witch flounder was calculated at 7.5, and assuming an ecotrophic efficiency of 95%, calculates a biomass of 0.54 tkm-2. Similarly, the ecotrophic efficiency of yellowtail flounder increased to 1.14 after balancing the above compartments, thus assuming an ecotrophic efficiency of 95% estimates a biomass of 0.21 tkm-2. The biomass of all flounders (yellowtail = 0.21 tkm-2, witch = 0.54 tkm-2 and winter = 0.05 tkm-2) is still lower than the 1.11 tkm-2estimated for all flounders in Bundy et al. (2000).   Shrimp  Shrimp ecotrophic efficiency was estimated at 1.13 when using the biomass, P/B and Q/B estimates obtained from Bundy et al. (2000), thus assuming an ecotrophic efficiency of 95% estimates a biomass of 2.36 tkm-2, which is nearly double the 1.5 tkm-2 obtained from Bundy et al. (2000). However, as the biomass estimated by Bundy et al (2000) was adapted from later data, we will keep the new estimate of shrimp biomass.  Large and small zooplankton  The ecotrophic efficiency of large zooplankton increased to above 100% after balancing the compartments above, and assuming an ecotrophic efficiency of 95% the biomass of large zooplankton increased to 24.8 tkm-2. This value is higher than, but comparable to, the 22.5 tkm-2 estimated in Bundy et al (2000).  A higher biomass of large zooplankton would need to be sustained by a larger biomass of small zooplankton, and the balancing of large zooplankton therefore increased the ecotrophic efficiency of small zooplankton to 104%. Thus assuming an ecotrophic efficiency of small zooplankton of 95% estimates a biomass of 37 tkm-2, which is larger than, but comparable to, the biomass of small zooplankton estimated in Bundy et al (2000).  Final changes to the model  Additional information on recreational catches (Table 14) became available from the 1985 and 1995 surveys of recreational fishing in Canada (Robyn Forrest, Fisheries Centre, UBC pers. comm.)  The predators of three species were also expanded, as they were under-represented in the model:  i. The predators of salmon were expanded to Ecosystem Models of Newfoundland, Past and Present, Page 24  include cetaceans, grey seals, piscivorous birds, skates and transient pelagics.  ii. The predators of large crabs were expanded to include grey, harp and hooded seals as well as large cod. iii. The predators of lobster were expanded to include walrus, large cod, skates, large demersal piscivores and other large demersal species.   The new biomass estimates were entered into the previously balanced model, and the new balanced model?s parameters are listed in Appendix D.   CONCLUSIONS  These models were adapted from Bundy et al. (2000), with an increase in the number of compartments, as well as a redistribution of species amongst compartments. In the 1985-87 model, the biomass estimates obtained from Lilly (pers. comm.) were mostly disregarded as they were not adjusted for catchability, and it was assumed that the estimates obtained by Bundy et al. (2000) were a truer representation of the biomass of these species. In the 1995-97 model no such guidelines were available, and in balancing that model the diets of the various fish species were changed more dramatically than in the 1985-87 model. This report gives a preliminary view of the ecosystem in 1995-97, and will be rebalanced when data on catchability coefficients for the Campelen trawl biomass estimates become available.   In subsequent work, time-series biomass data from 1985 to 1997 will be fitted, and the effects of climatic change, (i.e. North Atlantic Oscillation Index) on the model groups will be investigated.   These static mass-balance ECOPATH models will be used as baselines for dynamic exploration using ECOSIM. Policy explorations in Back to the Future aim to determine what fisheries could be sustained by the Newfoundland marine ecosystem if it were restored to its state in 1985 or 1995. Fishery options will be explored for sustainably managing each of these ecosystems in future, so that the value of each system, if restored and sustainably fished, can be compared using the Back to the Future technique (Sumaila et al. 2001).    ACKNOWLEDGEMENTS  The authors wish to thank Garry Stenson, Becky Sjare, Earl Dawe, Don Bowen, Dave Kulka, Don Power, Dave Reddin, Brian Dempson, Brian Nakashima, John Anderson, Pierre Pepin, Jerry Ennis, Ray Bowering, Sam Naidu and Joanne Morgan of DFO in St. John?s, Newfoundland. Special acknowledgement is given to George Lilly who extracted the biomass and diet information of most fish species (especially groundfish) and to Alida Bundy (BIO) for her contribution to the model breakdown. Reg Watson kindly extracted the mesopelagic data from the Sea Around Us database. Acknowledgement is also given to Don Deibel, Bill Montevecchi, Barb Neis, Ransom Myers, Jeff Hutchings and Jon Lien for information, data and discussions on the construction of the model. Robyn Forrest of the Fisheries Center, UBC is acknowledged for help in obtaining recreational catches for both time periods.   REFERENCES  Ancellin, J., 1954. Observations sur la morue de Terre-Neuve et du Labrador. Rapp. P.-v. R?un. CIEM 136:72-76. Allen, G. M. 1942. Family Odobenidae: Walruses. Pages 469-477 in Extinct and vanishing mammals of the Western Hemisphere with Marine Species of all the oceans. American Committee for International Wild Life Protection Special Publication No. 11. Cooper Sq. Publishers, Inc., New York, N.Y. Anderson, J. T., Davis, D. J., Dalley, E. L. and Carscadden, J. E. 2001. Abundance and Biomass of Juvenile and Adult Capelin in the Newfoundland Region (NAFO 2J3KL) Estimated from the Pelagic Juvenile Fish Surveys, 1994-1999. 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Was an increase in natural mortality responsible for the collapse of northern cod? Canadian Journal of Fisheries and Aquatic Science 52:1274-1285. Myers, R. A., Hutchings, J. A. and Barrowman, N. J. 1997b. Why do fish stocks collapse? The example of cod in Atlantic Canada. Ecological Applications 7:91-106. Nammack, M.J., Musick, J.A. and Colvocoresses, J.A. 1985. Life history of spiny dogfish off the northeastern United States. Trans. Am. Fish. Soc. 114:367-376. O'Driscoll, R. L., Schneider, D. C., Rose, G. A. and Lilly, G. R. 2000. Potential contact statistics for measuring scale-dependent spatial pattern and association: an example of northern cod (Gadus morhua) and capelin (Mallotus villosus). Canadian Journal of Fisheries and Aquatic Science 57:1355-1368. Parsons, D. G., Veitch, P. J., Orr, D. and Evans, G. T. 2000. Assessment of northern shrimp (Pandalus borealis) off Baffin Island, Labrador and northeastern Newfoundland. Research Document 2000/069, Canadian Stock Assessment Secretariat, Ottawa. Pauly, D. 1980. On the interrelationships between natural mortality, growth parameters, and mean environmental temperature in 175 fish stocks. Journal du Conseil International pour l'Exploration de la Mer 39: 175-192. Pauly, D. and Christensen, V. 1995. Primary production required to sustain global fisheries. Nature 374: 255-257. Pitcher, T. J. 2001. Rebuilding ecosystems as a new goal for fisheries Management: Reconstructing the past to salvage the future. Ecological Applications 11(2): 601-617. Pitcher, T., Heymans, J.J. and 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. Pauly, D., Soriano-Bartz, M.L. and Palomares, M.L.D. 1993. Improved construction, parameterisation and interpretation of steady-state ecosystem models. Pages 1-13 in Christensen, V. and Pauly, D. (eds.) Trophic models of aquatic ecosystems. ICLARM Conf. Proc. 26. Pitt, T.K. 1975. Changes in the abundance and certain biological characteristics of Grand Bank American plaice, Hippoglossoides plattessoides. J. Fish. Res. Board Can. 32(8):1383-1398. Prowse, D.W. 1972. A history of Newfoundland. Mika Studio Belleville, originally published by MacMillan and Co. London, 1895. Rose, G. A., deYoung, B., Kulka, D. W., Goddard, S. V. and Fletcher, G. L. 2000. Distribution shifts and overfishing the northern cod (Gadus morhua): a view from the ocean. Canadian Journal of Fisheries and Aquatic Science 57:644-663. Rostlund, E. 1952. Freshwater fish and fishing in native North America. University of California Publications in Geography, Vol. 9. University of  California Press, Berkeley. Shelton, P. A. and Stansbury, D. E. 2000. Northern cod recruitment before, during and after collapse. Research Document 2000/089, DFO, Canadian Science Advisory Secretariat, St. John?s, Newfoundland. Stenson, G. and Hammill, M. 2002a. Harp seals, Page 40 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 pp. Stenson, G. and Hammill, M. 2002b. Hooded seals, Pages 40-41 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 pp. Stenson, G.B. and  Sjare, B. 1997. Newfoundland hooded seal tag returns in the Northeast Atlantic. Sci. Counc. Stud. NAFO. 26: 115-118, Dec 1996. Stenson, G., Sjare, B. and Hammill, M. 2002. Whales and Porpoises. Page 39 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 pp. Stevenson, S.C. and Baird, J.W. 1988. The fishery for lumpfish (Cyclopterus lumpus) in Newfoundland waters. Canadian Technical Report of Fisheries and Aquatic Sciences, No. 1595, 26 pp. Sumaila, R.S., Pitcher, T.J., Haggan, N. and Jones, R. 2001. Evaluating the Benefits from Restored Page 27, Back to the Future on Canada?s East Coast   Ecosystems: A Back to the Future Approach. Pages 1-7, Chapter 18 in Shriver, A.L. and Johnston, R.S. (eds) Proceedings of the 10th International Conference of the International Institute of Fisheries Economics and Trade, Corvallis, Oregon, USA, July, 2000. (on CD-ROM) Taggart, C. G., Anderson, J. T., Bishop, C. A., Colbourne, E. B., Hutchings, J. A., Lilly, G. R., Morgan, J., Murphy, E. F., Myers, R. A., Rose, G. A. and Shelton, P. A. 1994. Overview of cod stocks, biology, and environment in the Northwest Atlantic region of Newfoundland, with emphasis on northern cod. ICES marine Science Symposium 198: 140-157. Tasker, M. L., Camphuysen, C. J., Cooper, J., Garthe, S., Montevecchi, W. A. and Blaber, S. J. M. 2000. The impacts of fishing on marine birds. ICES Journal of Marine Science 57: 531-547. Trites, A. W., Livingston, P. A., Mackinson, S., Vasconcellos, M., Springer, A. M. and Pauly, D. 1999. Ecosystem Changes and the Decline of Marine Mammals in the Eastern Bering Sea. Testing the Ecosystem Shift and Commercial Whaling Hypotheses. Fisheries Centre Research Reports 7(1), 106 pp. Vasconcellos, M., Power, M., Heymans, J.J. and Pitcher, T. 2002a. Workshop notes on seabirds.  Page 42 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 pp. Vasconcellos, M., Heymans, J.J. and Pitcher, T. 2002b. Historic reference points for models of past ecosystems in Newfoundland. Pages 7-13 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 pp. Vasconcellos, M., Power, M., Heymans, J.J. and Pitcher, T. 2002c. Workshop notes on small piscivorous pelagic fish. Pages 54-55 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 pp. Vasconcellos, M., Power, M., Heymans, J.J. and Pitcher, T. 2002d. Workshop notes on Northern Cod. Pages 43-45 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 pp. Walsh, D., Sjare, B. and Stenson, G. B. 2000. Preliminary estimates of Harp Seal by-catch in the Newfoundland Lumpfish fishery. Research Document 2000/078, Department of Fisheries and Oceans, Ottawa, 16 pp. Waring, G.T. 1984. Age, growth, and mortality of the little skate off the northeast coast of the United States. Trans. Am. Fish. Soc. 113: 314-321. Watson, R., Gu?nette, S., Fanning, P. and Pitcher, T.J.  2000. The Basis for Change 1: Reconstructing Fisheries Catch and Catch and Effort Ddata. Pages 23-39 in Pauly, D. and Pitcher, T.J. (eds) Methods for Evaluting the Impacts of Fisheries on North Atlantic Ecosystems. Fisheries Centre Research Reports 8(2), 195 pp.  Wright, B. S. 1951. A walrus in the Bay of Fundy; the first record. The Canadian Field-Naturalist 65: 61-63.   Ecosystem Models of Newfoundland, Past and Present, Page 28  APPENDICES  APPENDIX A:    MODEL GROUPS AND SPECIES IN NEWFOUNDLAND    # Ecopath Group Species 1 Walrus Odobenus rosmarus 2    Cetaceans    Humpback whale (Megaptera novaeangliae), fin whale (Balaenoptera physalus), minke whale (B. acutorostrata), sei whale (B. borealis), blue whale (B. musculus) sperm whale (Physeter catodon), pilot whale (Globicephala melaena) and harbour porpoise (Phocoena phocoena) 3 Grey seals Halichoerus grypus 4 Harp Seals Phoca groenlandica 5 Hooded Seals Cystophora cristata 6  Ducks  Common eider (Somateria mollissima), scoters (Melanitta spp.) and oldsquaws (Clangula hyemalis) 7         Piscivorous birds         Great auk (Pinguinus impennis), northern gannet (Sula bassana), great cormorants (Phalacrocorax carbo), double crested cormorant (P. auritus), herring gull (Larus argentatus) ring-billed gull (L. delawarensis) common black-headed gull (L. ridibundus), black-legged kittiwakes (Rissa tridactyla), common tern (Sterna hirundo), arctic tern (S. paradisaea), Caspian tern (Sterna caspia), common murre (Uria aalge), thick-billed murre (U. lomvia), black guillemot (Cepphus grylle), razorbill (Alca torda) and Atlantic puffins (Fratercula arctica), northern fulmar (Fulmarus glacialis), Manx shearwater (Puffinus puffinus) greater shearwater (Puffinus gravis) and sooty shearwater (P. griseus) 8 Planktivorous birds Leach's storm petrel (Oceanodroma leucorhoa) and dovekies (Alle alle) 9 Juvenile Cod > 35 cm 10 Adult Cod ? 35 cm Gadus morhua  11 American Plaice >35 cm 12 American Plaice ?35 cm Hippoglossoides platessoides 13 Greenland Halibut > 40 cm 14 Greenland Halibut ? 40 cm  Reinhardtius hippoglossoides 15 Yellowtail flounder Limanda ferruginea 16 Witch flounder Glyptodephalus cynoglossus 17 Winter flounder Pseudopleuronectes americanus 18  Skates  Barndoor (Raja laevis), thorny (R. radiata), smooth (R. senta), winter (R. ocellata) and little skate (Leucoraja erinacea) 19 Dogfish Squalus acanthias 20 Redfish Deepwater redfish (Sebastes mentella) and Acadian redfish (S. fasciatus) 21 Transient mackerel   > 29cm Scomber scombrus 22  Demersal and bentho-pelagic piscivores > 40 cm 23  Demersal and bentho-pelagic piscivores ? 40 cm White hake (Urophycis tenuis) silver hake (Merluccius bilinearis), monkfish (Lophius americanus), sea raven (Hemitripterus americanus), cusk (Brosme brosme) and Atlantic halibut (Hippoglossus hippoglossus)  24 Other large demersals   > 30 cm 25 Other large demersals  ? 30 cm Haddock (Melanogrammus aeglefinus), longfin hake (Phycis chesteri) and red hake (Urophycis chuss), wolffish (Anarhichas spp.), grenadiers (Coryphaenoides spp.), eelpouts (Lycodes spp.) and batfishes (Ogcocephalidae)   26    Small demersals    Rocklings (Enchelyopus spp.), gunnel (Pholis gunnellus), alligator fishes (Ulcina olriki), Atlantic poachers (Leptagonus decagonus), snakeblennies (Lumpenus lampretaeformis), shannies (Leptoclinus spp.), sculpin (Myoxocephalus spp.), searobins (Prionotus spp.), eelblennies (Anisarchus spp.)  27 Lumpfish Lumpsuckers (Cyclopterus lumpus) 28 Greenland cod Gadus opac 29 Atlantic salmon Salmo salar 30 Capelin Mallotus villosus 31 Sandlance Ammodytes dubius 32 Arctic cod Boreogadus saida 33 Herring Clupea harengus harengus 34  Transient pelagics   Bluefin tuna (Thunnus thynnus), swordfish (Xiphias gladius), porbeagle (Lamna nasus), basking shark (Cetorhinus maximus) and other sharks (Elasmobranchii). 35   Small pelagics   Shad (Alosa sapidissima), butterfish (Peprilus triacanthus), argentine (Argentina silus), juvenile mackerel (Scomber scombrus) and Atlantic rainbow smelt (Osmerus mordax mordax) 36  Small mesopelagics  Laternfishes (Myctophidae), pearlsides (Maurolicus muelleri) and barracudinas (Paralepis elongata) Page 29, Back to the Future on Canada?s East Coast   # Ecopath Group Species 37 Shortfin squid Illex illecebrosus 38 Arctic squid Gonatus spp. 39  Large crabs (> 95 mm CW)  Snow crab (Chionoecetes opilio), jonah crabs (Cancer borealis), red crabs (Chaceon quinquedens) and northern stone crabs (Lithodes maia) 40  Small crabs (? 95 mm)  Toad crabs (Hyas areneus and H. coarctatus), hermit crabs (Pagurus spp.), rock crabs (Cancer irroratus) and juvenles of large crabs 41 American lobster Lomarus americanus 42 Shrimps Northern shrimp (Pandalus borealis) and deep water shrimp (Pandalus montagui) 43 Echinoderms Sea urchin (Strongylocentrotus palliddus), sand dollars (Echinarachnius parma) and others 44 Polycheates Prionospio steenstrupi and others 45 Bivalves Sea scallops (Placopecten magellanicus), Icelandic scallop (Chlamys islandicus), propeller clams (Cyrtodaria siliqua), chalky macoma (Macoma calcarea) and others 46 Other benthic invertebrates Brittlestar (Ophiura sarsi) and others 47 Large zooplankton Euphausiids, Chaetognaths, hyperiid amphipods, Cnidarians and Ctenophores (jellyfish), mysids, tunicates >5 mm and icthyoplankton  48 Small zooplankton Copepods (Calanus finmarchicus and Oithona similis), tunicates < 5 mm and meroplankton 49 Phytoplankton Diatoms (Cahetoceros decipiens, Thalassiosira spp.) and others 50 Detritus    Ecosystem Models of Newfoundland, Past and Present, Page 30  APPENDIX B:    DIET  MATRICES   Table 1: Diet matrix for the 1995-1997 model. Note that diets for most fish species were obtained from Lilly (pers. comm.).  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1                 2                 3 0.0010                4 0.0010                5 0.0010                6                 7    0.0001             8                 9   0.1000 0.0071 0.0141            10  0.0100 0.0910 0.0087 0.0424  0.0057  0.0264 0.0080 0.0001 0.0005 0.0300 0.0050   11    0.0106             12 0.0100  0.0070 0.0388     0.0261 0.0002 0.0003 0.0010 0.0001    13    0.0052 0.0923            14   0.0010 0.0151 0.2768    0.0020 0.0008 0.0001 0.0005 0.0700 0.0055   15 0.0043  0.0070 0.0003 0.0208    0.0025  0.0003 0.0010     16 0.0043  0.0300 0.0734 0.0775    0.0004  <0.0001  0.0002    17 0.0043  0.0300 <0.0001 0.0208    0.0004        18   0.0040 <0.0001     0.0008    0.0001    19  0.0012               20   0.0060 0.0024 0.1195    0.0046 0.0001  0.0005 0.1516 <0.0001   21   0.0050    0.0004          22  0.0150               23 0.0020 0.0150 0.0410 <0.0001   0.0036  0.0000 0.0001       24  0.0150  0.0018 0.0129        0.0050    25 0.0100 0.0150 0.0260 0.0041 0.0386  0.0036  0.0215 0.0028 0.0070 0.0099 0.2710 0.0500   26 0.0160  0.0030 0.0179   0.0036  0.0110 0.0138 0.0021 0.0234 0.0020 0.0094  0.0090 27  0.0060 0.0150    0.0036  0.0006        28 0.0020 0.0020 0.0040 0.0013   0.0036  0.0004        29   0.0020    0.0004          30 0.0440 0.4889 0.0120 0.4359 0.0060  0.7928  0.4349 0.3310 0.1454 0.2577 0.3400 0.7500 0.0394  31  0.0520 0.4510 0.1466   0.0566  0.2448 0.1183 0.2676 0.1600  0.0015 0.0404  32   0.0020 0.0541 0.0725  0.0680  0.0084 0.0106 0.0002 0.0023 0.0100 0.0498   33  0.0540 0.0750 0.0843 0.0700  0.0109  0.0402 0.0153       34   0.0050  0.0080  0.0004      <0.0001    35  0.0550 0.0430  0.0290  0.0060  0.0004        36  0.0300 0.0100 0.0004   0.0170  0.0007 0.0022   0.0300 0.0150   37   0.0300 0.0072 0.0495  0.0060  0.0015    0.0223 0.0150   38  0.0540  0.0004 0.0495  0.0109  0.0008 0.0006 0.0009 0.0001 0.0550 0.0311   39                  40 0.1200   0.0001     0.0538 0.0786 0.0562 0.0350 0.0000   0.0010 41                 42 0.1200   0.0653   0.0068  0.0241 0.0441 0.0014 0.0136 0.0106 0.0350  0.0210 43 0.0500        0.0068 0.0004 0.3112 0.0850  0.0001 0.0734 0.0060 44 0.1000        0.0094 0.0178 0.0108 0.0849 <0.0001 <0.0001 0.4043 0.6600 45 0.3000   <0.0001  0.9000   0.0417 0.0189 0.0929 0.0334   0.0298 0.0110 46 0.2000   <0.0001  0.1000   0.0064 0.1325 0.0769 0.1300 0.0015 0.0035 0.3702 0.2910 47  0.1040  0.0188    0.9569 0.0295 0.2039 0.0265 0.1600 0.0006 0.0291 0.0426 0.0010 48 0.0100 0.0830      0.0431  0.0001  0.0010     49                 50                  Page 31, Back to the Future on Canada?s East Coast   Appendix B, Table 1. (continued)  17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 1                 2                 3                 4                 5                 6                 7                 8                 9                 10  0.0344 0.0200 0.0020  0.0538 0.0271 0.0017 0.0009    0.0022    11                 12  0.0015    0.0675 0.0340 0.0010 0.0005        13                 14  0.0008 0.0025   0.0019 0.0010      0.0011    15      0.0114 0.0057          16  0.0046    0.0038 0.0019          17                 18      0.0038 0.0019 0.0003 0.0002        19                 20  0.1360 0.0530 0.0070  0.0232 0.0117 0.0185 0.0093        21                 22                 23  0.0417 0.0125   0.1302 0.0656 0.0003 0.0002        24                 25  0.1120 0.0350 0.0010  0.1474 0.0743 0.0004 0.0002 0.0020  0.0100     26 0.0710 0.0278 0.0100   0.1022 0.0515 0.0013 0.0007 0.0080  0.2000     27                 28                 29                 30  0.1251 0.1510 0.0070 0.5000 0.1216 0.0613 0.0306 0.0154 0.0200 0.1000 0.4000 0.4828 0.0050  0.0380 31  0.1251 0.0500 0.0040 0.0500 0.1752 0.0882 0.0120 0.0061 0.0100 0.0010 0.0500 0.1831 0.0050   32  0.0008 0.0010  0.0500     0.0050 0.0020 0.0500    0.0020 33   0.0700  0.0500   0.0001 <0.0001 0.0020 0.0020 0.0200 0.1155    34                 35   0.0200   0.0213 0.0107 0.0080 0.0040 0.0010 0.0020      36  0.0077 0.0500 0.2330  0.0372 0.0188 0.0543 0.0274    0.1924    37  0.0591 0.0250   0.0076 0.0415 0.0001 0.0001   0.0050     38  0.0008 0.1000 0.0120    0.0038 0.0041  0.0020 0.0050 0.0044    39                 40 0.0018 0.2160    0.0107 0.0589 0.0875 0.0939 0.0100  0.0600     41                 42  0.0136 0.1750 0.0350  0.0214 0.1173 0.0784 0.0842 0.0200 0.0100 0.1200 0.0060    43 0.1023 0.0030    0.0031 0.0172 0.3189 0.3423 0.1000 0.0100 0.0200     44 0.1318 0.0561 0.0250   0.0032 0.0175 0.0873 0.0937 0.2000 0.0100 0.0150     45 0.0563 0.0008      0.0271 0.0291 0.0500  0.0050     46 0.6367 0.0296 0.0250  0.3000 0.0104 0.0569 0.1865 0.2002 0.4720 0.0100 0.0200     47  0.0023 0.1750 0.5380 0.0500 0.0405 0.2226 0.0744 0.0799 0.0500 0.8010 0.0200 0.0125 0.4390 0.3500 0.6400 48  0.0013  0.1610  0.0026 0.0145 0.0073 0.0078 0.0500 0.0500   0.5510 0.6500 0.3200 49                 50                  Ecosystem Models of Newfoundland, Past and Present, Page 32  Appendix B, Table 1. (continued)  33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 1                 2                 3                 4                 5                 6                 7                 8                 9                 10  0.0010   0.2150            11                 12                 13                 14                 15                 16                 17                 18                 19                 20  0.0020               21                 22                 23  0.0120   0.0003            24                 25  0.0120   0.0003            26  0.0110   0.0003            27  0.0000               28  0.0010               29                 30  0.0750  0.0100 0.3590            31  0.0860   0.1260            32     0.0030            33  0.1150   0.0580            34                 35  0.1150               36  0.1150  0.0500 0.0290            37  0.0565               38  0.0565  0.0400 0.0290            39                 40       0.0010  0.0100        41                 42  0.0120     0.0200 0.0500 0.0200        43       0.3030 0.0500 0.3000        44  0.0030     0.3030 0.1000 0.3000 0.0150       45       0.1200 0.2500 0.1200        46 0.1000 0.0190     0.1200 0.1500 0.1200 0.0150       47 0.5130 0.2950 0.7500 0.4500 0.1800 0.5000 0.0200 0.2000 0.0200 0.1200     0.0500  48 0.3870 0.0130 0.2500 0.4500  0.5000 0.0100 0.1500 0.0100 0.2400     0.4800  49          0.0850     0.3700 1.0000 50       0.1030 0.0500 0.1000 0.5250 1.0000 1.0000 1.0000 1.0000 0.1000   Page 33, Back to the Future on Canada?s East Coast   Table 2. Diet matrix for the 1985-1987 model. Note that diets for most fish species were obtained from Lilly (pers. comm.).  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1                 2                 3 0.0010                4 0.0010                5 0.0010                6                 7    0.0001             8                 9   0.1000 0.0032 0.0141            10  0.0100 0.0910 0.0060 0.0424  0.0057  0.0177 0.0065 0.0001 0.0043 0.0764 0.0087   11    0.0108             12 0.0100  0.0070 0.0387     0.0171 0.0003 0.0009 0.0209 0.0010    13    0.0078 0.0923            14   0.0010 0.0169 0.2768    0.0057 0.0023 0.0010 0.0019 0.1270 0.0055   15 0.0043  0.0070 0.0000 0.0208    0.0009 0.0000 0.0001 0.0079     16 0.0043  0.0300 0.0726 0.0775    0.0001  0.0001  0.0024    17 0.0043  0.0300 0.0001 0.0208    <0.0001        18   0.0040 0.0000     0.0002    0.0010    19  0.0012               20   0.0060 0.0030 0.1195    0.0086 0.0001  0.0008 0.2565 <0.0001   21   0.0050    0.0004          22  0.0150               23 0.0020 0.0150 0.0410 0.0000   0.0036  0.0001 0.0001       24  0.0150  0.0065 0.0129            25 0.0100 0.0150 0.0260 0.0060 0.0386  0.0036  0.0247 0.0050 0.0044 0.0057 0.0696 0.0004   26 0.0160  0.0030 0.0129   0.0036  0.0145 0.0188 0.0049 0.0147 0.0158 0.0072  0.0090 27  0.0060 0.0150    0.0036  0.0003        28 0.0020 0.0020 0.0040 0.0011   0.0036  0.0003        29   0.0020    0.0004          30 0.0440 0.4889 0.0120 0.4544 0.0060  0.7928  0.5976 0.4297 0.2973 0.3357 0.3829 0.8338 0.0394  31  0.0520 0.4510 0.1460   0.0566  0.1048 0.0309 0.1687 0.0905 0.0000 0.0002 0.0404  32   0.0020 0.1113 0.0725  0.0680  0.0218 0.0322 0.0006 0.0037 0.0267 0.0498   33  0.0540 0.0750 0.0102 0.0700  0.0109  0.0050 0.0159       34   0.0050  0.0080  0.0004      0.0004    35  0.0550 0.0430 0.0000 0.0290  0.0060          36  0.0300 0.0100 0.0004   0.0170  0.0016 0.0005   0.0089 0.0085   37   0.0300 0.0075 0.0495  0.0060  0.0012    0.0006    38  0.0540  0.0004 0.0495  0.0109  0.0026 0.0019 0.0006 0.0001 0.0125 0.0311   39                 40 0.1200   0.0002     0.0496 0.0236 0.0486 0.0249 0.0000   0.0010 41                 42 0.1200   0.0690   0.0068  0.0370 0.0787 0.0029 0.0127 0.0133 0.0222  0.0210 43 0.0500        0.0043 0.0002 0.2976 0.1118  0.0001 0.0734 0.0060 44 0.1000        0.0059 0.0170 0.0165 0.1106 0.0000 0.0000 0.4043 0.6600 45 0.3000     0.9000   0.0198 0.0047 0.0599 0.0217   0.0298 0.0110 46 0.2000     0.1000   0.0120 0.1390 0.0751 0.1398 0.0019 0.0035 0.3702 0.2910 47  0.1040  0.0153    0.9569 0.0466 0.1924 0.0206 0.0923 0.0031 0.0291 0.0426 0.0010 48 0.0100 0.0830      0.0431 0.0000 0.0002  0.0001     49                 50                 Ecosystem Models of Newfoundland, Past and Present, Page 34  Appendix B, Table 2. (continued)  17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 1                 2                 3                 4                 5                 6                 7                 8                 9                 10  0.0344 0.0200 0.0020  0.0538 0.0271 0.0017 0.0009    0.0022    11                 12  0.0015    0.0675 0.0340 0.0010 0.0005        13                 14  0.0008 0.0025   0.0019 0.0010      0.0011    15      0.0114 0.0057          16  0.0046    0.0038 0.0019          17                 18      0.0038 0.0019 0.0003 0.0002        19                 20  0.1360 0.0530 0.0070  0.0232 0.0117 0.0185 0.0093        21                 22                 23  0.0417 0.0125   0.1302 0.0656 0.0003 0.0002        24                 25  0.1120 0.0350 0.0010  0.1474 0.0743 0.0004 0.0002 0.0020  0.0100     26 0.0710 0.0278 0.0100   0.1022 0.0515 0.0013 0.0007 0.0080  0.2000     27                 28                 29                 30  0.1251 0.1510 0.0070 0.5000 0.1216 0.0613 0.0306 0.0154 0.0200 0.1000 0.4000 0.4828 0.0050  0.0380 31  0.1251 0.0500 0.0040 0.0500 0.1752 0.0882 0.0120 0.0061 0.0100 0.0010 0.0500 0.1831 0.0050   32  0.0008 0.0010  0.0500     0.0050 0.0020 0.0500    0.0020 33   0.0700  0.0500   0.0001 0.0000 0.0020 0.0020 0.0200 0.1155    34                 35   0.0200   0.0213 0.0107 0.0080 0.0040 0.0010 0.0020      36  0.0077 0.0500 0.2330  0.0372 0.0188 0.0543 0.0274    0.1924    37  0.0591 0.0250   0.0076 0.0415 0.0001 0.0001   0.0050     38  0.0008 0.1000 0.0120    0.0038 0.0041  0.0020 0.0050 0.0044    39                 40 0.0018 0.2160    0.0107 0.0589 0.0875 0.0939 0.0100  0.0600     41                 42  0.0136 0.1750 0.0350  0.0214 0.1173 0.0784 0.0842 0.0200 0.0100 0.1200 0.0060    43 0.1023 0.0030    0.0031 0.0172 0.3189 0.3423 0.1000 0.0100 0.0200     44 0.1318 0.0561 0.0250   0.0032 0.0175 0.0873 0.0937 0.2000 0.0100 0.0150     45 0.0563 0.0008      0.0271 0.0291 0.0500  0.0050     46 0.6367 0.0296 0.0250  0.3000 0.0104 0.0569 0.1865 0.2002 0.4720 0.0100 0.0200     47  0.0023 0.1750 0.5380 0.0500 0.0405 0.2226 0.0744 0.0799 0.0500 0.8010 0.0200 0.0125 0.4390 0.3500 0.6400 48  0.0013  0.1610  0.0026 0.0145 0.0073 0.0078 0.0500 0.0500   0.5510 0.6500 0.3200 49                 50                  Page 35, Back to the Future on Canada?s East Coast   Appendix B, Table 2. (continued)  33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 1                 2                 3                 4                 5                 6                 7                 8                 9                 10  0.0010   0.2150            11                 12                 13                 14                 15                 16                 17                 18                 19                 20  0.0020               21                 22                 23  0.0120   0.0003            24                 25  0.0120   0.0003            26  0.0110   0.0003            27                 28  0.0010               29                 30  0.0750  0.0100 0.3590            31  0.0860   0.1260            32     0.0030            33  0.1150   0.0580            34                 35  0.1150               36  0.1150  0.0500 0.0290            37  0.0565               38  0.0565  0.0400 0.0290            39                 40       0.0010  0.0100        41                 42  0.0120     0.0200 0.0500 0.0200        43       0.3030 0.0500 0.3000        44  0.0030     0.3030 0.1000 0.3000 0.0150       45       0.1200 0.2500 0.1200        46 0.1000 0.0190     0.1200 0.1500 0.1200 0.0150       47 0.5130 0.2950 0.7500 0.4500 0.1800 0.5000 0.0200 0.2000 0.0200 0.1200     0.0500  48 0.3870 0.0130 0.2500 0.4500  0.5000 0.0100 0.1500 0.0100 0.2400     0.4800  49          0.0850     0.3700 1.0000 50       0.1030 0.0500 0.1000 0.5250 1.0000 1.0000 1.0000 1.0000 0.1000   Ecosystem Models of Newfoundland, Past and Present, Page 36  APPENDIX C:   BALANCED MODEL AND DIET MATRIX 1995-1997  Input parameters of the balanced 1995-1997 model (values in bold are estimated by Ecopath). Group name Trophic level Biomass P/B Q/B EE P/Q Walrus 3.30 0.000001 0.060 16.846 0.000 0.004 Cetaceans 3.86 0.251 0.100 11.742 0.002 0.009 Grey seals 4.34 0.000001 0.060 15.000 0.281 0.004 Harp Seals 4.13 0.405 0.102 17.412 0.432 0.006 Hooded Seals 4.39 0.062 0.109 13.100 0.283 0.008 Ducks 3.00 0.000227 0.250 54.750 0.247 0.005 Piscivorous Birds 4.19 0.013 0.250 54.750 0.352 0.005 Planktivorous Birds 3.30 0.003 0.250 54.750 0.241 0.005 Adult Cod > 40cm 4.04 0.181 0.300 3.240 0.950 0.093 Juv Cod ? 40 cm 3.73 0.198 1.600 6.090 0.950 0.263 American plaice >35cm 3.38 0.954 0.088 2.000 0.950 0.044 American plaice ?35cm 3.54 0.850 0.400 3.736 0.950 0.107 Greenland halibut >65cm 4.28 0.750 0.098 1.478 0.950 0.066 Greenland halibut ? 65 cm 4.11 1.082 0.397 4.480 0.950 0.089 Yellowtail Flounders 3.10 0.330 0.319 3.600 0.507 0.089 Witch flounder 3.02 0.471 0.348 2.304 0.950 0.151 Winter flounder 3.01 1.302 0.267 1.644 0.950 0.163 Skates 4.11 0.208 0.320 2.878 0.424 0.111 Dogfish 3.87 0.017 0.194 4.770 0.950 0.041 Redfish 3.51 1.472 0.148 2.000 0.950 0.074 Transient Mackerel ( >29cm) 3.77 0.004 0.290 4.400 0.950 0.066 Large demersal piscivores (> 40 cm) 4.20 0.023 0.206 1.107 0.950 0.186 Large demersal piscivores (? 40cm) 3.63 0.968 0.147 1.660 0.950 0.088 Large Demersal Feeders (> 30cm) 3.24 0.265 0.229 1.386 0.950 0.166 Small demersal feeders 3.12 8.381 0.232 2.079 0.950 0.112 Other small demersals 3.09 0.580 0.564 4.474 0.950 0.126 Lumpfish 3.38 0.039 0.116 1.374 0.950 0.084 Greenland cod 3.96 0.002 0.594 1.265 0.950 0.470 Salmon 4.14 0.009 0.614 4.093 0.950 0.150 Capelin 3.15 5.443 1.150 4.300 0.950 0.267 Sandlance 3.13 4.302 0.620 7.670 0.950 0.081 Arctic cod 3.25 1.408 0.573 2.633 0.950 0.218 Herring 3.14 3.365 0.541 4.131 0.950 0.131 Transient Pelagics 3.91 0.041 0.400 3.333 0.950 0.120 Small Pelagics 3.19 9.688 0.638 5.291 0.950 0.121 Small Mesopelagics 3.21 2.036 1.422 4.789 0.950 0.297 Shortfin squid 3.95 1.101 0.600 4.000 0.950 0.150 Arctic Squid 3.09 4.127 0.500 3.333 0.950 0.150 Large Crabs (>95 cm) 2.91 0.179 0.380 4.420 0.989 0.086 Small Crabs  (? 95 cm) 3.03 0.081 0.630 4.420 0.950 0.143 Lobster 2.93 0.003 0.380 4.420 0.950 0.086 Shrimp 2.43 1.104 1.450 9.670 0.914 0.150 Echinoderms 2.00 112.300 0.600 6.670 0.140 0.090 Polychaetes 2.00 10.500 2.000 6.330 0.236 0.316 Bivalves 2.00 42.100 0.570 22.220 0.066 0.026 Other benthic invertebrates 2.00 7.800 2.500 12.500 0.552 0.200 Large zooplankton 2.31 25.722 3.433 19.500 0.950 0.176 Small zooplankton 2.00 30.367 8.400 20.670 0.903 0.406 Phytoplankton 1.00 47.887 93.100 - 0.207 - Detritus 1.00 412.176 - - 0.420 -   Page 37, Back to the Future on Canada?s East Coast   Balanced diet in 1995-1997:  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1                2                3 0.001               4 0.001               5 0.001               6                7    0.0001            8                9   0.1001 0.0070 0.0010           10  0.0010 0.0911 0.0090 0.0010  0.0157  0.0330 0.0088 0.0001 0.0006 0.0360 0.0193  11    0.0110            12 0.010  0.0070 0.0401     0.0330 0.0002 0.0004 0.0010 0.0001   13    0.0050 0.0100           14   0.0010 0.0150 0.1191    0.0030 0.0009 0.0001 0.0006 0.0839 0.0212  15 0.004  0.0070 0.0003 0.0420    0.0030  0.0003 0.0010    16 0.004  0.0300 0.0201 0.0020    0.0010    0.0002   17 0.004  0.0300 0.0411 0.0480    0.0010       18   0.0040 0.0000     0.0010    0.0001   19  0.0010              20   0.0060 0.0020 0.0100    0.0060 0.0001  0.0006 0.0502   21   0.0050    0.0010         22  0.0010              23 0.002 0.0260 0.0410 0.0000   0.0105   0.0001      24  0.0010  0.0020 0.0310        0.0060   25 0.010 0.0260 0.0260 0.0040 0.0891  0.0105  0.0270 0.0031 0.0091 0.0116 0.3249 0.1929  26 0.016  0.0030 0.0181   0.0105  0.0140 0.0151 0.0027 0.0050 0.0024 0.0056  27  0.0010 0.0150    0.0010  0.0010       28 0.002 0.0001 0.0001 0.0001   0.0001  0.0001       29  0.0010 0.0020    0.0010         30 0.044 0.0999 0.0120 0.4443 0.0130  0.1011  0.0999 0.1000 0.1885 0.1018 0.1004 0.0538 0.0394 31  0.0100 0.4545 0.1494   0.1494  0.3087 0.1296 0.1225 0.1018  0.0058 0.0404 32   0.0020 0.0552 0.1662  0.1782  0.0110 0.0116 0.0003 0.0027 0.0120 0.0011  33  0.0010 0.0751 0.0853 0.1592  0.2063  0.0509 0.0168      34   0.0050  0.0170  0.0010         35  0.3586 0.0430  0.0651  0.2063  0.2517 0.2520  0.1760 0.2398 0.3271  36  0.0519 0.0100 0.0004   0.0445  0.0010 0.0024   0.0360 0.0579  37   0.0300 0.0070 0.1131  0.0157  0.0020    0.0267 0.0579  38  0.0939  0.0004 0.1131  0.0288  0.0010 0.0007 0.0012 0.0001 0.0659 0.1200  39   0.0010 0.0001 0.0010    0.0010       40 0.120   0.0001     0.0010 0.0010 0.0010 0.0010    41 0.0001        0.0001       42 0.120   0.0662   0.0183  0.0310 0.0483 0.0018 0.0160 0.0127 0.0112  43 0.050        0.0090 0.0004 0.4035 0.0998  0.0004 0.0734 44 0.100        0.0120 0.0195 0.0140 0.0996   0.4043 45 0.300   0.0000  0.9000   0.0529 0.0207 0.1205 0.0392   0.0298 46 0.200   0.0000  0.1000   0.0080 0.1452 0.0997 0.1526 0.0018 0.0135 0.3702 47  0.1818  0.0191    0.957 0.0370 0.2234 0.0344 0.1878 0.0007 0.1123 0.0426 48 0.010 0.1459      0.043  0.0001  0.0012    49                50                 Ecosystem Models of Newfoundland, Past and Present, Page 38  1995-1997 diet continued?  16 17 18 19 20 21 22 23 24 25 26 27 28 29 1               2               3               4               5               6               7               8               9               10   0.0451 0.0200 0.0020  0.0539 0.0001 0.0001 0.0011    0.0022 11               12   0.0020    0.0679 0.0011 0.0011 0.0006     13               14   0.0010 0.0025   0.0020 0.0014      0.0011 15       0.0110 0.0067       16   0.0070    0.0040 0.0029       17               18       0.0040 0.0029 0.0003 0.0002     19               20   0.0501 0.0530 0.0070  0.0230 0.0171 0.0203 0.0011     21               22               23   0.0611 0.0125   0.1299 0.0001 0.0003 0.0002     24               25   0.1643 0.0350 0.0010  0.1469 0.1085 0.0004 0.0002 0.0020  0.0100  26 0.0090 0.0050 0.0411 0.0100   0.1019 0.0050 0.0014 0.0009 0.0079  0.2000  27               28               29   0.0010            30   0.1834 0.1510 0.0070 0.5000 0.1219 0.0899 0.0336 0.0188 0.0200 0.1000 0.4000 0.4828 31   0.1834 0.0500 0.0040 0.0500 0.1748 0.0054 0.0120 0.0011 0.0100 0.0010 0.0500 0.1831 32   0.0010 0.0010  0.0500     0.0050 0.0020 0.0500  33    0.0700  0.0500   0.0001  0.0020 0.0020 0.0200 0.1155 34               35    0.0200   0.0210 0.0157 0.0088 0.0049 0.0010 0.0020   36   0.0110 0.0500 0.2330  0.0370 0.0285 0.0596 0.0335    0.1924 37   0.0872 0.0250   0.0080 0.0614 0.0001 0.0001   0.0050  38   0.0010 0.1000 0.0120    0.0042 0.0050  0.0020 0.0050 0.0044 39               40 0.0010 0.0019 0.0060    0.0110 0.0011 0.0010 0.0001 0.0100  0.0600  41   0.0001    0.0010  0.0001      42 0.0210  0.0200 0.1750 0.0350  0.0210 0.1713 0.0861 0.0109 0.0200 0.0100 0.1200 0.0060 43 0.0060 0.1096 0.0040    0.0030 0.0243 0.3502 0.4187 0.1000 0.0100 0.0200  44 0.6600 0.1412 0.0822 0.0250   0.0030 0.0257 0.0959 0.1146 0.2000 0.0100 0.0150  45 0.0110 0.0603 0.0010      0.0298 0.0356 0.0500  0.0050  46 0.2910 0.6820 0.0431 0.0250  0.3000 0.0100 0.0842 0.2048 0.2449 0.4720 0.0100 0.0200  47 0.0010  0.0030 0.1750 0.5380 0.0500 0.0410 0.3254 0.0817 0.0977 0.0500 0.8010 0.0200 0.0125 48   0.0020  0.1610  0.0030 0.0214 0.0080 0.0095 0.0500 0.0500   49               50                Page 39, Back to the Future on Canada?s East Coast   1995-1997 diet continued?  30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 1                    2                    3                    4                    5                    6                    7                    8                    9                    10     0.0010   0.0001            11                    12                    13                    14                    15                    16                    17                    18                    19                    20     0.0020               21                    22                    23     0.0120   0.0008            24                    25     0.0120   0.0008            26     0.0110   0.0008            27                    28     0.0010               29     0.0010               30 0.005  0.038  0.0749  0.01 0.0101            31 0.005    0.0859   0.0101            32   0.002     0.0093            33     0.1149   0.1717            34                    35     0.1149   0.3673            36     0.1149  0.05 0.0859            37     0.0569               38     0.0569  0.04 0.0859            39                    40          0.001  0.01        41                    42     0.0120     0.020 0.05 0.02        43          0.303 0.05 0.30        44     0.0030     0.303 0.10 0.30 0.015       45          0.120 0.25 0.12        46    0.1127 0.0190     0.120 0.15 0.12 0.015       47 0.439 0.4 0.640 0.4510 0.2947 0.6 0.30 0.2572 0.3 0.020 0.20 0.02 0.120     0.01  48 0.551 0.6 0.320 0.4363 0.0130 0.4 0.60  0.7 0.010 0.15 0.01 0.240     0.30  49             0.085     0.59 1.0 50          0.103 0.05 0.10 0.525 1.0 1.0 1.0 1.0 0.10   Ecosystem Models of Newfoundland, Past and Present, Page 40  APPENDIX D:    BALANCED MODEL AND DIET MATRIX 1985-1987  Input parameters of the balanced 1985-87 model (values in bold are estimated by Ecopath). Group name Trophic level Biomass P/B Q/B EE P/Q Walrus 3.32 0.000001 0.060 16.846 0.000 0.004 Cetaceans 4.11 0.251 0.100 11.794 0.000 0.009 Grey seals 4.45 0.000001 0.060 16.000 0.281 0.004 Harp Seals 4.24 0.184 0.102 17.412 0.161 0.006 Hooded Seals 4.78 0.034 0.109 13.100 0.048 0.008 Ducks 3.00 0.0002 0.250 54.750 0.333 0.005 Piscivorous Birds 4.28 0.010 0.250 54.750 0.409 0.005 Planktivorous Birds 3.53 0.002 0.250 54.750 0.325 0.005 Adult Cod > 40cm 4.16 1.811 0.404 3.240 0.777 0.125 Juv Cod ? 40 cm 3.86 0.302 1.600 6.090 0.943 0.263 American plaice >35cm 3.66 0.722 0.224 2.000 0.844 0.112 American plaice ?35cm 3.68 0.773 0.630 3.740 0.950 0.168 Greenland halibut >65cm 4.53 0.361 0.300 1.480 0.950 0.203 Greenland halibut ? 65 cm 4.23 0.474 0.870 4.480 0.746 0.194 Yellowtail Flounders 3.12 0.214 0.534 3.600 0.950 0.148 Witch flounder 3.02 0.550 0.588 2.305 0.950 0.255 Winter flounder 3.08 0.048 0.267 1.644 0.950 0.163 Skates 4.24 0.235 0.361 2.878 0.520 0.125 Dogfish 4.01 0.018 0.193 4.770 0.950 0.041 Redfish 3.68 1.450 0.489 2.000 0.950 0.245 Transient Mackerel ( >29cm) 3.85 0.373 0.300 4.400 0.166 0.068 Large demersal piscivores (> 40 cm) 4.34 0.124 0.617 4.111 0.950 0.150 Large demersal piscivores (? 40cm) 3.97 3.257 0.147 1.400 0.950 0.105 Large Demersal Feeders (> 30cm) 3.36 0.416 0.272 1.747 0.950 0.156 Small demersal feeders 3.28 3.698 0.232 2.000 0.950 0.116 Other small demersals 3.11 1.189 0.564 4.500 0.950 0.125 Lumpfish 3.59 0.225 0.114 1.400 0.950 0.082 Greenland cod 4.04 0.103 0.166 1.300 0.950 0.128 Salmon 4.26 0.013 0.614 4.093 0.950 0.150 Capelin 3.26 12.977 1.150 4.300 0.950 0.267 Sandlance 3.20 2.614 1.150 7.667 0.950 0.150 Arctic cod 3.41 2.319 0.400 2.633 0.950 0.152 Herring 3.29 1.254 0.544 4.100 0.950 0.133 Transient Pelagics 4.08 0.012 0.400 1.990 0.950 0.201 Small Pelagics 3.42 0.521 0.638 1.767 0.950 0.361 Small Mesopelagics 3.38 1.164 1.422 4.789 0.950 0.297 Shortfin squid 4.06 0.519 0.600 4.000 0.950 0.150 Arctic Squid 3.28 1.507 0.500 3.333 0.950 0.150 Large Crabs (>95 cm) 2.92 0.174 0.380 4.420 0.277 0.086 Small Crabs  (? 95 cm) 3.08 4.758 0.380 4.420 0.950 0.086 Lobster 2.93 0.005 0.380 4.420 0.959 0.086 Shrimp 2.46 2.363 1.450 9.667 0.950 0.150 Echinoderms 2.00 112.300 0.600 6.667 0.082 0.090 Polychaetes 2.00 10.500 2.000 22.222 0.296 0.090 Bivalves 2.00 42.100 0.570 6.333 0.258 0.090 Other benthic invertebrates 2.00 7.800 2.500 12.500 0.543 0.200 Large zooplankton 2.56 24.834 3.433 19.500 0.950 0.176 Small zooplankton 2.00 36.997 8.400 20.667 0.950 0.406 Phytoplankton 1.00 26.860 93.100 - 0.378 - Detritus 1.00 389.000 - - 0.629 -  Page 41, Back to the Future on Canada?s East Coast   Balanced diet in 1985-1987  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1                2                3 0.0010               4 0.0010               5 0.0010               6                7    0.0001            8                9   0.0999 0.0032 0.0141           10  0.0120 0.0909 0.0060 0.0423  0.0057  0.0175 0.0065 0.0001 0.0044 0.0765 0.0087  11    0.0108            12 0.0100  0.0070 0.0373     0.0254 0.0002 0.0003 0.0010 0.0001   13    0.0078 0.0922           14   0.0010 0.0169 0.2765    0.0056 0.0023 0.0010 0.0019 0.1271 0.0055  15 0.0043  0.0070 0.0000 0.0207    0.0009  0.0001 0.0081    16 0.0043  0.0300 0.0726 0.0774    0.0001  0.0001  0.0024   17 0.0043  0.0300 0.0001 0.0207           18   0.0040 0.0000     0.0002    0.0010   19  0.0010              20   0.0060 0.0030 0.1194    0.0085 0.0001  0.0008 0.2567   21   0.0050    0.0004         22  0.0180              23 0.0020 0.0180 0.0410 0.0000   0.0036  0.0001 0.0001      24  0.0180  0.0065 0.0129           25 0.0100 0.0180 0.0260 0.0060 0.0386  0.0036  0.0245 0.0050 0.0044 0.0058 0.0697 0.0004  26 0.0160  0.0030 0.0129   0.0036  0.0144 0.0188 0.0049 0.0150 0.0158 0.0072  27  0.0070 0.0150    0.0036  0.0003       28 0.0020 0.0030 0.0040 0.0011   0.0036  0.0003       29  0.0010 0.0020    0.0004         30 0.0440 0.4410 0.0120 0.4545 0.0060  0.7927  0.5919 0.4297 0.2975 0.3425 0.3832 0.8337 0.0394 31  0.0120 0.4505 0.1460   0.0566  0.1038 0.0309 0.1688 0.0923  0.0002 0.0404 32   0.0020 0.1113 0.0724  0.0679  0.0216 0.0322 0.0006 0.0038 0.0267 0.0498  33  0.0640 0.0749 0.0102 0.0699  0.0109  0.0050 0.0159      34   0.0050  0.0080  0.0004      0.0004   35  0.0650 0.0430 0.0000 0.0290  0.0060         36  0.0350 0.0100 0.0004   0.0170  0.0016 0.0005   0.0089 0.0085  37   0.0300 0.0075 0.0495  0.0060  0.0012    0.0006   38  0.0640  0.0004 0.0495  0.0109  0.0026 0.0019 0.0006 0.0001 0.0125 0.0311  39   0.0010 0.0010 0.0010    0.0010       40 0.1200   0.0002     0.0491 0.0236 0.0486 0.0254    41 0.0001        0.0000       42 0.1200   0.0691   0.0068  0.0366 0.0787 0.0029 0.0130 0.0133 0.0222  43 0.0500        0.0043 0.0002 0.2978 0.1141  0.0001 0.0734 44 0.1000        0.0058 0.0170 0.0165 0.1128   0.4043 45 0.3000   0.0000  0.9000   0.0196 0.0047 0.0599 0.0221   0.0298 46 0.2000   0.0000  0.1000   0.0119 0.1390 0.0752 0.1426 0.0019 0.0035 0.3702 47  0.1240  0.0153    0.9569 0.0462 0.1924 0.0206 0.0942 0.0031 0.0291 0.0426 48 0.0100 0.0990      0.0431  0.0002  0.0001    49                50                 Ecosystem Models of Newfoundland, Past and Present, Page 42  1985-1987 diet continued?  16 17 18 19 20 21 22 23 24 25 26 27 28 29 1               2               3               4               5               6               7               8               9               10   0.0344 0.0200 0.0020  0.0538 0.0271 0.0017 0.0009    0.0022 11               12   0.0015    0.0675 0.0329 0.0010 0.0005     13               14   0.0008 0.0025   0.0019 0.0010      0.0011 15       0.0114 0.0057       16   0.0046    0.0038 0.0019       17               18       0.0038 0.0019 0.0003 0.0002     19               20   0.1358 0.0530 0.0070  0.0232 0.0117 0.0185 0.0093     21               22               23   0.0416 0.0125   0.1302 0.0657 0.0003 0.0002     24               25   0.1119 0.0350 0.0010  0.1474 0.0744 0.0004 0.0002 0.0020  0.0100  26 0.0090 0.0710 0.0278 0.0100   0.1022 0.0516 0.0013 0.0007 0.0080  0.2000  27               28               29   0.0010            30   0.1250 0.1510 0.0070 0.5000 0.1216 0.0614 0.0306 0.0154 0.0200 0.1000 0.4000 0.4828 31   0.1250 0.0500 0.0040 0.0500 0.1752 0.0883 0.0120 0.0061 0.0100 0.0010 0.0500 0.1831 32   0.0008 0.0010  0.0500     0.0050 0.0020 0.0500  33    0.0700  0.0500   0.0001  0.0020 0.0020 0.0200 0.1155 34               35    0.0200   0.0213 0.0107 0.0080 0.0040 0.0010 0.0020   36   0.0077 0.0500 0.2330  0.0372 0.0188 0.0543 0.0274    0.1924 37   0.0590 0.0250   0.0076 0.0415 0.0001 0.0001   0.0050  38   0.0008 0.1000 0.0120    0.0038 0.0041  0.0020 0.0050 0.0044 39               40 0.0010 0.0018 0.2157    0.0107 0.0590 0.0875 0.0939 0.0100  0.0600  41   0.0001    0.0001  0.0001      42 0.0210  0.0136 0.1750 0.0350  0.0214 0.1174 0.0784 0.0842 0.0200 0.0100 0.1200 0.0060 43 0.0060 0.1023 0.0030    0.0031 0.0172 0.3189 0.3422 0.1000 0.0100 0.0200  44 0.6600 0.1318 0.0560 0.0250   0.0032 0.0175 0.0873 0.0937 0.2000 0.0100 0.0150  45 0.0110 0.0563 0.0008      0.0271 0.0291 0.0500  0.0050  46 0.2910 0.6368 0.0296 0.0250  0.3000 0.0104 0.0570 0.1865 0.2002 0.4720 0.0100 0.0200  47 0.0010  0.0023 0.1750 0.5380 0.0500 0.0405 0.2228 0.0744 0.0799 0.0500 0.8010 0.0200 0.0125 48   0.0013  0.1610  0.0026 0.0145 0.0073 0.0078 0.0500 0.0500   49               50                Page 43, Back to the Future on Canada?s East Coast   1985-1987 diet continued?  30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 1                    2                    3                    4                    5                    6                    7                    8                    9                    10     0.001   0.001            11                    12                    13                    14                    15                    16                    17                    18                    19                    20     0.002               21                    22                    23     0.012   0.001            24                    25     0.012   0.001            26     0.011   0.001            27                    28     0.001               29     0.001               30 0.01  0.04  0.075  0.010 0.478            31 0.01    0.086   0.016            32   0.00     0.004            33     0.115   0.098            34                    35     0.115               36     0.115  0.050 0.049            37     0.056               38     0.056  0.040 0.049            39                    40          0.001  0.01        41                    42     0.012     0.020 0.05 0.02        43          0.303 0.05 0.30        44     0.003     0.303 0.10 0.30 0.02       45          0.120 0.25 0.12        46    0.10 0.019     0.120 0.15 0.12 0.02       47 0.44 0.35 0.64 0.51 0.295 0.750 0.450 0.304 0.500 0.020 0.20 0.02 0.12     0.05  48 0.55 0.65 0.32 0.39 0.013 0.250 0.450  0.500 0.010 0.15 0.01 0.24     0.48  49             0.09     0.37 1.00 50          0.103 0.05 0.10 0.53 1.00 1.00 1.00 1.00 0.10     Ecosystem Models of Newfoundland, Past and Present, Page 44  A PICASSO-ESQUE VIEW OF THE MARINE ECOSYSTEM OF NEWFOUNDLAND AND SOUTHERN LABRADOR: MODELS FOR THE TIME PERIODS 1450 AND 1900  Johanna J. (Sheila) Heymans  and  Tony J. Pitcher Fisheries Centre, UBC   INTRODUCTION  The marine ecosystem of Newfoundland and southern Labrador (2J3KLNO) has probably changed more over the past 500 years than can ever be captured. This description of the Newfoundland system therefore becomes more abstract (i.e. more like a Picasso painting) as we go back in time. One could expect that the 1990s and 1980s models described in Heymans and Pitcher (this volume) would be a close proximity to the true ecosystem. The 1900s and 1450s models, however, are less certain, although a great deal of information from historical, archival and archaeological sources has been incorporated in as objective a fashion as possible. As one would expect, scientific information available for constructing the 1900 and 1450 models was not forthcoming, and it was therefore necessary to use any historical information available to us, even if it was taken from secondary sources. We did not have resources to use professional help from historians or archivists to verify material from secondary sources.  The effect of anthropogenic changes on this ecosystem was probably noticeable as soon as the Basque whalers arrived (Dunfield 1985). Before the early 1900s, represented by the second model, 1900-1905, the great auk, walrus and grey seals were effectively extinct, with many cetaceans also following the same path. The effects of the cod fishery were noticeable from around the early 1700s with local extinctions of the inshore stocks (Dunfield 1985), when the English bank fishery started (Anon. 2000a). However, the most noticeable changes were probably seen subsequent to the start of the trawl fishery on the Grand Banks in 1948 (Andersen 1998). The changes in the ecosystem over the past fifty year period, which is probably known better than any time, are myriad: large changes in the groundfish community occurred from the 1950s to the 1970s on the Grand Banks (Casey and Myers 2001). The reduction in the biomass of major species (cod and haddock) fundamentally changed the groundfish community structure and reduced the total species biomass by 90% from the 1950s to the 1990s (Casey and Myers 2001). During this decrease in gadoid biomass on the southern Grand Bank, flatfish biomass increased and dominated from the late 1960s into the early 1980s. Biomass of Atlantic cod, haddock and white hake was greatest in the 1950s, with cod and haddock being equally abundant. Redfish biomass has increased on the southern Grand Banks in the 1980s, but decreased overall since the 1950s (Casey and Myers 2001).  The objective of this paper is to attempt to give a  quantitative description of the marine ecosystem of Newfoundland and southern Labrador (2J3KLNO) as it was in 1900 and in 1450. These models will be used in simulations of the ecosystem over time and exploration of alternative sustainable fisheries options for the Back to the Future project (Pitcher 2001).   The models consist of 50 compartments: 48 consumers, one primary producer (phyto-plankton) and one detritus group. In some cases, groups have gone extinct (walrus and grey whales), and we have kept these compartments in the models (with very low biomass estimates) for comparison between them. In most compartments the diet composition was taken to be the same as the 1980s diet composition given in Heymans and Pitcher (this volume).   MODEL DESCRIPTION BY GROUP  1) Walrus  In glacial times the walrus was found as far south as the coast of Virginia, while at the time of the discovery of America by Europeans, their distribution did not come further south than Massachusetts Bay and in colonial times their most southern breeding ground was Sable Island off Nova Scotia (Allen 1942). According to Mowat (1984 p. 308) walruses existed in untold numbers as far south as Cape Cod on the Atlantic shores prior to European contact. Loring (1992) suggested that walrus were once fairly prolific along the Labrador coast and were present in small sociable groups concentrated at favored hauling-out places. In the past century only five walruses (Odobenus rosmarus, Linnaeus) have been recorded in the 2J3KLNO area: two in 1949 and three in 1967 (Mercer 1967). In 1904 Ganong (Ganong 1904) reported that they do not occur further south than Labrador and in 1951 (Wright 1951) suggested that they are not found south of Hudson Strait anymore. However, Reeks (1871 p. 2550) found that:   From the quantity of "tusks" picked up on the coasts of Newfoundland, the walrus must Page 45, Back to the Future on Canada?s East Coast   have been an inhabitant of the island, or perhaps, like the harp seal, migrated thither on the drift-ice.  Mowat (1984 p. 311) suggested that the Central Gulf herd numbered at least a quarter of a million individuals (300,000 tonnes of wet mass) when Europeans first came upon it. Additionally, the Seal Conservation Society reports that the Atlantic walrus has not been able to recover and is still well below its pre-exploitation level of several hundred thousand (Anon. 2001a).  For our pre-contact model it was assumed that the Atlantic herd was something more than that of the Sable Island herd (100,000 as reported by Mowat 1984 p. 304) and less than the Central Gulf herd (1/4 million as reported by Mowat 1984 p. 311). An abundance of 125,000 walruses was therefore estimated. Brenton (1979) estimated the average weight for male and female walruses to be 1,200 kg and 750 kg respectively. With an average weight of 750 kg the biomass of walruses in 2J3KLNO was estimated at 0.25 tkm-2. Biomass in the 1900 model was assumed to be very low (0.000001 tkm-2) as we had to have some estimate of biomass in the model even though they were not really present. The P/B ratio of 0.06 yr-1, obtained from walruses in the Bering Sea model (Trites et al. 1999) was used. According to FAO (1978) they consume 45 kg of food per day, which gives a Q/B of 16.8 yr-1. First Nations were assumed to have caught walruses; it was assumed that part of the 20% of First Nations diet attributed to seals consisted of walruses (Heymans 2002). Thus we assume that 0.020 kgkm-2yr-1 was caught by First Nations. Catches of walrus were not made in any of the subsequent time periods.  Walruses live to be at least 40 years of age and are preyed upon by polar bears and killer whales (Anon. 2001a). They are mostly found in shallow continental shelf waters, usually less than 100m deep, and they feed mostly on invertebrates that live in or on the bottom sediments (Anon. 2001a).  Brenton (1979) suggests that 65 species of benthic invertebrates, principally mollusks, echinoderms, tunicates, crustaceans, priapulids and echiuroids are consumed, and the Seal Conservation Society and Allen (1942) report that their diet occasionally includes seals and rarely fish. In the Bering Sea, seal eating was 10 to 100 times more common during the 1970s and early 1980s than during the previous three decades, due to the greater overlap in their distribution during that time (Lowry and Fay 1984). The diet of walruses in the Bering Sea model (Trites et al. 1999) was adapted for this ecosystem in the 1980s and 1990s models. 2) Cetaceans  Cetaceans were the main draw to the coasts of Newfoundland for Basque fishermen. By the mid-1500s most of the train oil extracted from seals, walrus, whales and seabirds was used as fuel for lamps and as sources for lubricants, leather and jute processing, while cooking oil came from right whales harvested in Newfoundland, Labrador and the Gulf of St. Laurence (Vasconcellos et al. 2002b). Cartier (Dunfield 1985) reported on the abundance of porpoises in the Gulf in the mid-1530s and, as long as the First Nations and Europeans only used them for food, their populations remained unaffected. In one of the notes on the drawings made by Shanawdithit, written by Mr. W.E. Cormack in 1829, reference was made to the bottlenose whales that frequented the Northern Bays, and how it was considered good luck for them to be killed by ?Red Indians? (Howley 1915).  Stenson et al. (2002) suggest that the biomass of whales in the 1900s was probably twice that of the present time period, or 0.502 tkm-2. For the 1500s model, the biomass of whales was estimated by assuming an ecotrophic efficiency of 95%. The P/B and Q/B estimates for cetaceans given by Bundy et al. (2000) were used in both models, although the P/B of the 1900s should probably be higher (whaling pressure was high) and the Q/B could be lower in the 1500s and 1900s models due to the larger individuals present in the populations at that time. The diet estimates made for the 1985-87 model by Bundy et al. (2000) were adapted for the new model groupings in Heymans and Pitcher (this volume).  Cushing (1988) suggested that the early settlers probably observed Indian methods of whaling. They attacked right whales from small boats close to shore, dragged them ashore and cut them up there, although some initial cutting was done at sea (Cushing 1988 p. 138). Sixteenth-century records showed that the combined Basque whaling fleet consisted of between 40 and 120 vessels in any given year and the fleet landed about 2,300 whales annually (Mowat 1984 p. 216). Add 20% to incorporate struck-and-lost mortality and calves that starved to death, and an estimate of 2,500 whales a year is reached for the time period 1515-1560 (Mowat 1984 p. 216). The average weight of adult black right whales was about 80-100 tonnes (FAO 1978). If we assume that the catch on the east coast was small compared to that of the Gulf of St. Lawrence (ca. 10% of the catch from 2J3KLNO), and if the  lower end of the weight range (80 tonnes) is used, the catch in the 1500s is estimated at 0.04 tkm-Ecosystem Models of Newfoundland, Past and Present, Page 46  2yr-1. This is similar to the total North Atlantic Basque catch of 300-500 right whales (0.06 tkm-2yr-1) estimated for 1530-1610 by Reeves et al. (1999). However, the pre-contact catch by Basque fishermen was probably much smaller and here it is assumed that catches were 10% of the estimated catch in 1515-1560, or 0.004 tkm-2yr-1. The catch of whales by First Nations was estimated at 0.001 kgkm-2yr-1 (Heymans 2002). The catch of whales from 1900 to 1905 (0.04 tkm-2yr-1) was estimated from numbers given by Sanger et al. (1998) (Table 1) and using average mean body weight (32 tonnes) for rorquals (humpbacks, fin, minke, sei and blue whales) given in Bundy et al. (2000).  Table 1: Catch estimates of whales in Newfoundlandfrom 1900-1905 (source: Sanger et al. 1998). Year Number of rorquals caught 1900 200 1901 250 1902 450 1903 850 1904 1300 1905 900 Average 658  3-5) Seals  Several kinds of seals frequented the northwestern approaches when the European invasion began. Four were pre-eminent: hood, harp, harbour and grey seals. Hoods and harps were the most numerous, but were only present during the winter and early spring, when the Europeans were not there. Grey and harbour seals were available year round (Mowat 1984 p. 325). Grey seals were abundant along the Atlantic coast of North America at first contact (Mowat 1984 p. 328) and gathered in January and February in enormous numbers on the islands and mainland beaches from Labrador to Cape Hatteras to whelp and breed. During the rest of the year they stayed together in inshore waters to fish together and hauled out to sun themselves on bars in salt-water lagoons and river mouths (Mowat 1984 p. 325).  3) Grey seals  Over 200 grey seal whelping rookeries originally existed between Cape Hatteras and Hamilton Inlet on the Labrador coast (NAFO area 2J) and that the total population probably totaled between 750,000 and 1,000,000 seals. Some of these rookeries were still producing 2,000 pups a year as late as the 1850s (Mowat 1984 p. 331). The average weight of a grey seal is about 220 kg (Hammill and Stenson 2000). The study area (2J3KLNO) is approximately a third of the total area of the population, but there were probably not as many rookeries on the Atlantic coast as in the Gulf of St. Lawrence. Thus we assumed that about 1/5th of the population, or 0.08 tkm-2, was in 2J3KLNO. For the 1900s a very small biomass of 0.000001 tkm-2 was assumed.  The P/B ratio of 0.06 yr-1 for seals in the Bering Sea model (Trites et al. 1999) was used for grey seals in all four models. Dommasnes et al. (2001) and Trites et al. (1999) estimated a Q/B ratio for grey seals in the Norwegian and Bering Seas of 15.0 and 15.93 yr-1 respectively. We used 15.0 yr-1 as a Q/B ratio for grey seals in Newfoundland. The diet of grey seals was adapted from Hammill and Stenson (2000) by Heymans and Pitcher (this volume).  4) Harp Seals  Mowat (1984 p. 347) records that a whelping patch off the southeast coast of Labrador in 1844 was estimated to be at least 50 miles long and 20 miles broad, and contained about 5 million seals. If we assume that this patch was similar to the whelping patch of Newfoundland in pre-contact times, we could use this as an estimate of harp seals in 2J3KLNO. However, by 1844 between 100,000 and 500,000 seals had been exported from Newfoundland annually (Sanger 1998) thus the biomass was probably much larger, and it was assumed that the biomass was double that in pre-contact times. Using an average weight of 130 kg (Anon. 2000b) and assuming that they only stay in the area ? the time, the pre-contact biomass was estimated at 1.3 tkm-2. Stenson and Hammill (2002a) suggest that the total harp seal population in the North Atlantic was probably between 6 and 12 million animals in the early 1900s. At an average weight of 130 kg (Anon. 2000b), assuming that the population in the Newfoundland-Labrador area is ? of the total population gives a biomass of 0.591 tkm-2. The P/B and Q/B ratios of 0.102 and 17.412 yr-1, respectively, were obtained from Bundy et al. (2000). Diet of harp seals obtained from Stenson (pers. comm., see Heymans and Pitcher, this volume) for 1985-1987 was used as the diet of seals in both 1900s and 1500s models.  5) Hooded Seals  Stenson and Hammill (2002b) suggest the biomass of hooded seals in the early 1900s was probably approximately 3 times the mid-1980s value, or 0.102 tkm-2. Mowat (1984 p.359) suggested that although hooded seals were never as abundant as harps, they may not have been far inferior in terms of biomass. It was assumed that Page 47, Back to the Future on Canada?s East Coast   the pre-contact biomass of hooded seals was in the same ratio as that of the 1900s, thus the biomass of hooded seals pre-contact was approximately 0.26 tkm-2. The P/B and Q/B ratios of 0.109 and 13.1 yr-1, respectively, obtained from Bundy et al. (2000) were used in both models. Diets were obtained from Hammill and Stenson (2000) and adapted for the groups in this model in the 1980s and 1990s (see Heymans and Pitcher, this volume).   Seal catches  All of the First Nations that lived in Newfoundland and Labrador relied on seals to a greater or lesser extent. To the Labrador Inuit in particular, the seal was until recently a staple component of a way of life largely adapted to local resources. The meat was eaten or fed to the dogs; the fat was rendered into oil for light and food; the skin was used for clothing, boots and a myriad of other purposes besides trade with European merchants (Hiller 2001). Natives used salmon nets with every other mesh cut away to catch seals (Dunfield 1985). Marshall (pers. comm.) suggests that seals probably made up 10% of the diet of Beothuk (or 20% of the diet of Beothuk and Inuit, both present in the area in pre-contact times). Thus, First Nations catches of seals in pre-contact times were estimated at 0.010 kgkm-2yr-1 of grey seals and 0.120 kgkm-2yr-1 of harp seals, based on their biomass ratio (Heymans 2002).  There is less traditional knowledge available for hooded seals as compared to harps because hooded seals are distributed further offshore and are not seen as often by coastal fishermen. This is also why it is assumed that there was no catch of hooded seals by First Nations. The catch statistics for hooded seals have been comprehensive since the 1950s. However, historic data from 1900 to 1950 are not as good as for harp seals, and the information available is summarized with harp seal data (Stenson and Hammill 2002b). The main problem is that for these early time periods hooded seals were not separated from harps in the statistics. According to Mowat (1984 p. 359), sealers took few hooded seals until well into the 19th century. The animals were too big and powerful to be held by nets and too tough to kill in open water with the firearms available.  Ryan (1994) gave the total number of seals exported from Newfoundland from 1861 to 1914. The average number exported from 1900 to 1905 was 326,648 and includes harp and hooded seals, of which both adults and juveniles were taken. Of the total catch, approximately 75% were probably taken from the 2J3KLNO population (Stenson, pers. comm.). Estimates of the proportion of harp and hooded seal adults and juveniles in the catches were obtained from Anon (1970) for 1937 to 1947 (Table 2), and used to calculate the proportions of adults and young seals caught in the 1900s. The average weights of juvenile and adult harp seals are approximately 32.5 kg and 100 kg respectively, and those of hooded seals are approximately 37.5 kg and 220 kg respectively (Hammill and Stenson 2000). Thus, the total catches of harp and hooded seals in 1900-1905 were probably around 0.017 tkm-2yr-1 and 0.002 tkm-2yr-1, respectively.  Table 2. Numbers of adult and juvenile harp and hooded seals caught from 1937 to 1947 (source: Anon. 1970). Year Young Harps Adult Harps Young Hoods Adult Hoods 1937 2796 898 6 15 1938 221297 21341 300 116 1939 102109 25798 2308 315 1940 132360 26188 961 178 1941 16636 25654 272 104 1942 1723 2032 927 16 1943 ? ? ? ? 1944 6360 25693 167 92 1945 9516 35432 4 8 1946 73000 29562 5171 734 1947 102294 74215 1851 2784 Average (%) 56.8 39.9 2.9 0.4 Catch  (tkm-2yr-1) 0.0091 0.0074 0.0015 0.0004   6-8) Seabirds  Mowat (1984 p. 75) suggested that two dozen species of ducks originally lived in or migrated through the northeastern region and were found in astounding numbers. Most species remained relatively numerous until the beginning of the 19th century after which they were over-exploited for market hunting. Canada, snow and brant geese abounded along the northeastern coasts (Mowat 1984 p. 75). Great auk rookeries were likely few in number, as with current auks, and at times huge (e.g. Funk Island) (Montevecchi and Kirk 1996). The Atlantic coast of Labrador was probably not favored for great auk breeding grounds as it had too much pack ice during the summer season (Mowat 1984 p. 26).  The common and thick-billed murres combined were probably the most numerous seabirds in North America when Europeans first arrived (Mowat 1984 p. 47). Two species of cormorant, the great and the double-crested, formerly bred along the coast from mid-Labrador southward and beside freshwater lakes and rivers (Mowat 1984 p. 45). They were exceedingly abundant and remained so into the 17th century because Ecosystem Models of Newfoundland, Past and Present, Page 48  Europeans considered them unfit for food, but the bait fishery put an end to their protection (Mowat 1984 p. 45). Four species of terns once bred in colonies on islands, beaches and sandbars in both fresh and salt water throughout the Atlantic seaboard. Terns were only utilized from the middle of the 19th century when feather hunters started exploiting their colonies (Mowat 1984 p. 46). Of the planktivorous species, Leach?s storm petrels once bred in enormous numbers on islands and headlands south at least to Cape Cod, but the encroachments of modern man and his associated animals have deprived them of most of their one-time rookeries (Mowat 1984 p. 44), except in Newfoundland where the world?s largest colonies are located (Montevecchi and Tuck 1987; Cairns et al. 1989).  In contrast to cormorants, storm-petrels, terns and the auk, most gull species benefited enormously from recent human activity, especially during the 20th century (Kadlec and Drury 1968). Herring, ring-billed and black-backed gulls and kittiwakes have staged a remarkable comeback from a centuries-long decline during which they and their eggs were taken in enormous numbers for human food. Their population increases are largely due to garbage generation and fishery offal and discards (Montevecchi, pers comm.). During pre-contact times, large seabird colonies were present off the east coast of Newfoundland, including Funk Island, situated approximately 50 kilometers offshore and known as the Isle of Birds in 1505. Funk Island was probably the site of the largest great auk colony in the world (Grieve 1885), where there may have been more than 100,000 nesting pairs (Nettleship and Birkhead 1985; Montevecchi and Tuck 1987; Montevecchi and Kirk 1996).   Surveys of coastal headlands, beaches, reefs, islands and islets from mid Labrador to Florida show that only about 3 out of every 100 suitable sites for seabird colonies are still occupied, even by vestigial populations (Mowat 1984 p. 50). If this ratio is used, the population of seabirds is now probably only 3% of what it was pre-contact. The biomass of the 1990s model was therefore increased ca. 33 times for the pre-contact model (Table 3). This value is probably a gross overestimation, as not all suitable sites would be used at all times, but it was used here as the upper estimate of what seabird numbers could have been in the pre-contact period until a better result is obtained. Vasconcellos et al. (2002a) suggest that the biomass of birds in 1900 was probably double what it is today (Table 3). The P/B and Q/B ratios for birds given in Bundy et al. (2000) were used for all three of these groups. The diet of seabirds used in Bundy et al. (2000) was adapted to the new groups by Heymans and Pitcher (this volume).  First Nations and early European settlers exploited many species of seabirds along the coast of Newfoundland as sources of food, bait, oil and feathers for bedding. One of the most affected species was the great auk (Montevecchi and Tuck, 1987; Vasconcellos et al. 2002b). The significance of great auks for First Nations is revealed by the number of their beaks uncovered in graves (Tuck 1975; Montevecchi and Tuck 1987; Montevecchi and Kirk 1996). They provided the Beothuk with eggs and meat. The Beothuks ground the dried contents of great auk eggs into a kind of flour with which they made puddings (Montevecchi and Tuck 1987). Marshall (1996) suggests that the Beothuk utilized murres, auks, puffins, kittiwakes, gulls, guillemots, gannets, cormorants, dovekies, geese and ducks, and all bird eggs. Marshall (pers. comm.) suggests that the diet of Beothuk and Inuit probably consisted of 10% birds (36.5 tonnes or 0.074 kgkm-2yr-1) (Heymans 2002). To estimate catches of each compartment, the total First Nations catch was divided by the biomass ratio of the bird compartments (Table 3). We also assume a similar catch made by First Nations and European settlers for the 1900s model, as fishermen used birds to bait their cod hooks from early in the 19th century (Tasker et al. 2000).  9-10) Cod   In 1497, Milan?s envoy to London, Raimondo di Soncino, reported that Cabot found the sea swarming with fish which can be taken not only with the net but also in a basket let down with a stone, so that it sinks in the water (Kurlansky 1997 p. 48). On the Newfoundland shore the cod were reported to be so thick that one was hardly able to row a boat through them (Mowat 1984  p. 168). Estimates of harvestable Northern cod biomass (2J3KL) prior to the offshore-dominated catches of the 1960s are given by Hutchings and Myers (1995) as 3,000,000 tonnes. This calculates a biomass of 8.2 tkm-2 using the area of 367,542 km2 given by Bundy (2002) for 2J3KL. We assumed this value as the overall biomass for Table 3. Estimates of seabird biomass (kgkm-2) in the 1990s, 1900, and 1450 models (assuming that only 3% of the colonies are presently still occupied).  1990s (tonnes) 1990s (kgkm-2) 1900 (kgkm-2) 1450 (kgkm-2) First Nations catch (kgkm-2yr-1) Ducks 83 0.227 0.453 7.554 0.001 Piscivores 4945 13.453 26.906 448.429 0.060 Planktivores 1073 2.921 5.841 97.353 0.013 Page 49, Back to the Future on Canada?s East Coast   the area 2J3KLNO for both the 1900s and 1500s models. To calculate the biomass of juvenile cod in the past models we assumed that the same rate of change of adult biomass applies to juveniles, i.e. historic biomass is 4 times the biomass in the mid-1980s (0.34 tkm-2) (Bundy et al. 2000). Therefore, the biomass of juvenile cod in the 1900s and 1500s models was estimated at 1.36 tkm-2. However, this might have to be estimated by ECOPATH to balance the model.  The natural mortality and Q/B ratios of all fish species were calculated by using empirical formulas obtained from Pauly (1980) and Palomares and Pauly (1998), respectively (Appendix A Table A1 and A2). For species such as cod, where fishing mortality was available or calculable, the sum of F and M was used to estimate P/B. Thus natural mortality of adult cod was estimated at 0.1 yr-1, and fishing mortality was 0.4 * 10-8 yr-1 in 1450 and 0.09 yr-1 in 1900, which calculates P/B ratios of approximately 0.104 and 0.198 yr-1 for 1450 and 1900, respectively. The natural mortality of juvenile cod was estimated at 0.155 yr-1 and was used as P/B ratio for both time periods (Appendix A Table A1). The Q/B ratios for adult and juvenile cod were estimated at 1.1 and 1.6 yr-1 respectively (Appendix A Table A2). Diet estimates obtained from Lilly (2002) for 1985-87 were used for juvenile and adult cod in both 1450 and 1900.  The average annual production of dried cod declined from about 791,000 quintals annually for 1884-1888 to about 486,000 quintals for the years 1909-1913 (Lear (1998) quoting Grant (1934)). Thus the catch of cod around 1900 was probably approximately 500,000 quintals. Myers (2001) suggests that 1 tonne of cod produces 4.2 quintals, which calculates a catch of approximately 120,000 tonnes for 1900, or 0.24 tkm-2 yr-1. However, Hutchings and Myers (1995) estimated a catch of approximately 280,000 tonnes (pers comm. for raw data), or 0.77 tkm-2 yr-1 for 2J3KL from 1900-1905, which was used here in the 1900s model.   11-12) American plaice  Estimates of biomass for American plaice, Hippoglossoides platessoides, were not available for the pre-contact model and were made by using ecotrophic efficiency values of 0.95 for both adult and juvenile American plaice. Natural mortality estimates (Appendix A Table A1) for adult and juvenile American plaice (0.08 and 0.12 yr-1, respectively) were used to estimate P/B ratios, and the Q/B ratios were calculated at 1.7 and 2.5 yr-1, respectively (Appendix A Table A2). Diet estimates for 1985-87, obtained from Lilly (2002), were used for American plaice in both 1900 and 1450. There was no reported commercial catch of American plaice before 1950 (Morgan et al. 2000) and therefore no catch estimates or fishing mortality were entered for American plaice in 1900. However, flounders are reported to have been part of the Beothuk diet (Marshall 1996), and the American plaice catch by First Nations is calculated at approximately 0.003 kgkm-2yr-1 (Heymans 2002).  13-14) Greenland halibut  Greenland halibut occur in NAFO areas 2G, 2H, 2J, 3K, 3L and 3N, and during the 1970s they were abundant in 2G, 2H and 2J, while they were reduced in those areas in the 1990s and increased in 3K, 3L and 3N (Bowering 2001). The biomass in 2J3K at the beginning of the time series (1978) was approximately 300,000 tonnes (Bowering 2001, Figure 7), ca. 230,000 tonnes of adults (> 35 cm), and 70,000 tonnes of juveniles (? 35 cm). These figures are used as a lower estimate of the biomass of Greenland halibut prior to the commercial fishery, which started in the 19th century (Table 4). Vasconcellos et al. (2002d p. 45) quote Barb Neis:  a fishery for Greenland halibut began in Trinity Bay during the 1960s, but the area was fished out within a year and then the fishery moved offshore.  Thus the biomass of Greenland halibut was probably already much lower by 1978. We therefore assume that the 1900 and 1450 biomasses were double the initial stock biomass estimated from the VPA (Bowering 2001), or 0.93 tkm-2 and 0.28 tkm-2 respectively for adult and juvenile Greenland halibut.  Natural mortality of adult Greenland halibut was calculated using an equation from Pauly (1980) with L? and K estimates for the northwest Atlantic (Bowering and Nedreaas 2001) and an average temperature of 2?C. The average M Table 4. Catch of various species during 1903 in Atlantic Canadaand estimates of catches in 2J3KLNO using assumptions ofdistribution for all species (see text).  Species Catch in Atlantic Canada (tonnes) % of population in 2J3KLNO Catch (kgkm-2yr-1) Haddock (Large Demersal) 7000 10% 1.414 Greenland halibut 2400 75% 3.636 Pollock  (Bentho-pelagic piscivore) 10000 1% 0.202 Mackerel 5000 1% 0.101 Capelin 10000 80% 16.162 Herring 4000 25% 2.020 Ecosystem Models of Newfoundland, Past and Present, Page 50  calculated was 0.026 yr-1 and if it is assumed that the juvenile natural mortality is 1.5 times that of adults, the M for juveniles is estimated at 0.04 yr-1 (Appendix A Table A1). Halibut was caught commercially at the turn of the 20th century (Table 4), thus a small fishing mortality of 0.004 yr-1 is added to the natural mortality of adults to calculate a P/B of 0.03 yr-1. P/B of juveniles was assumed the same as the natural mortality rate of 0.04 yr-1. The Q/B ratios for adults and juveniles were calculated at 1.2 and 1.8 yr-1, respectively (Appendix A Table A2) and the diet obtained from Lilly (2002) for 1985-87 was used for both models. It was assumed that the catch (if any) of Greenland halibut made by First Nations in both time periods was too small for the models. A catch estimate of Greenland halibut in Atlantic Canada in 1903 was obtained from Regier and McCracken (1975) (Table 4). The distributions of haddock, Greenland halibut and pollock in 2J3KLNO (compared to the rest of Atlantic Canada) were estimated from the East Coast of North America Strategic Assessment Project website2. Based on the above information it was assumed that 10% of haddock, 75% of Greenland halibut and 1% of pollock caught were caught in 2J3KLNO.  15-17) Flounders (yellowtail, witch, winter)  Yellowtail flounder, Limanda ferruginea, are mainly located on Grand and St. Pierre Banks, although they do occur up to the Strait of Belle Isle, and prefer temperatures of 3.1-4.8?C (Pitt 1970). Yellowtail flounder abundance increased from 1961-1968 coincident with higher bottom temperatures. The close association between the species distribution and bottom temperatures could be explored in a future work as a way to estimate historical trends in relative abundance of the species in the study area. However, in the present work, the biomass in 1900 and 1450 was estimated by assuming an ecotrophic efficiency of 95%. Yellowtail flounder was caught commercially from 1965, when 1,800 tons were landed from the Grand Bank. However, no catches were made around 1900 or pre-contact.   Witch flounder Glyptocephalus cynoglossus reaches its northern limits near Hamilton Bank off southern Labrador (Anon. 1996b). The fishery began in the 1960s and the peak catch in 2J3KL was 24,000 metric tonness in 1973 (Bowering 2000). However, no catches were made around 1900 or pre-contact.                                                   2 http://www-orca.nos.noaa.gov/projects/ecnasap/appendix1.html Winter flounder Pseudopleuronectes amer-icanus is a shallow water species that occurs around the coast of Newfoundland (Anon. 1996a). Winter flounder has been taken in 3K and 3L with gillnets and as lobster bait for years, and the gillnet fishery supported limited food markets since the 1970s (Anon. 1996a). However, no catches were made around 1900 or pre-contact.  The diets of all three species were assumed to be similar to their diet in 1985-1987 (Lilly 2002). The natural mortalities of yellowtail, witch and winter flounder were estimated in Appendix A Table A1 and used as P/B ratios for three species in both 1900 and 1450. The Q/B ratios calculated in Appendix A Table A2 for witch and winter flounder were also used for both models. It was not possible to estimate the Q/B of yellowtail founder due to the lack of parameters for the L-W relationship. Instead the Q/B of the species was calculated as the average Q/B ratio of yellowtail flounder on the Georges Bank (3.271 yr-1) obtained from Sissenwine (1987). However, this ratio is probably too high, as the 1900 and 1450 population would probably have a higher proportion of old animals.  Flatfishes formed part of the diet of First Nations (Marshall 1996), although it was probably only the inshore species. Thus, the pre-contact catch of yellowtail and winter flounder by First Nations is calculated at 0.002 kgkm-2yr-1 and 0.001 kgkm-2yr-1 respectively (Heymans 2002). No known catches of flounders are available for 1900-1905.  18) Skates  This group consists of barndoor skates, Dipturus laevis, thorny skates Amblyraja radiata, smooth Malacoraja senta, little Leucoraja erinacea and winter skates Leucoraja ocellata. Thorny skates are the dominant species in the area and George Lilly was quoted by Vasconcellos et al. (2002e p. 48) as saying that   although some references say barn door skates have largely disappeared, they are still caught in commercial fisheries.   Vasconcellos et al. (2002e) suggest that the biomass in the early 1900s was probably higher than in the mid-1980s considering that large quantities of skates were discarded since the beginning of trawling, and proposed that the biomass of skates in the 1900s should be twice the number estimated for the mid-1980s. A biomass of 0.47 tkm-2 was therefore estimated for 1900. Biomass of skates in 1450 was estimated by assuming an ecotrophic efficiency of 95% and Page 51, Back to the Future on Canada?s East Coast   their diet in both models was assumed to be similar to their diet in 1985-1987 (Lilly 2002). The natural mortality estimated in Appendix A Table A1 for little skates was used as P/B ratio in both 1900 and 1450 and their Q/B ratio calculated in Appendix A Table A2 was also used for both models. Skates were not caught in 1900 or 1450.  19) Dogfish  Spiny dogfish, Squalus acanthias, was separated from the large pelagic feeders in Bundy et al. (2000). No estimates were available for 1900 or pre-contact dogfish biomass, and it was therefore estimated by ECOPATH using an ecotrophic efficiency of 0.95. The P/B ratio was taken to be similar to natural mortality (0.16 yr-1 in Appendix A Table A1) and the Q/B ratio of 2.2 yr-1 was estimated in Appendix A Table A2. The diet of dogfish in 1900 and 1450 was assumed to be similar to the 1985-87 diet (Lilly 2002). Dogfish was not caught in 1900 or pre-contact.  20) Redfish  Species of redfish, (= ocean perch, rosefish) in the study area include deep-water redfish Sebastes mentella, and Acadian redfish S. fasciatus (Anon. 1996d). Biomass was estimated for both models by assuming an ecotrophic efficiency of 95% each, and natural mortality (0.11 yr-1) was assumed to be the same as P/B, while the Q/B ratio (1.7 yr-1) calculated in Appendix A Table A2 was assumed to be similar for both models. The diet in 1900 and 1450 was assumed to be similar to the 1985-87 diet (Lilly 2002), and redfish was not caught in 1900 or pre-contact.  21) Transient mackerel (> 29 cm)  Mackerel, Scomber scombrus, comprise a single stock in the study area and in some years they are present in large quantities, while in other years they are virtually absent (Vasconcellos et al. 2002c). Adult transient mackerel larger than 29 cm were therefore split from the small pelagic group. Biomass was estimated for both models by assuming an ecotrophic efficiency of 95%, and natural mortality (0.007 yr-1, obtained using the equation of Pauly, 1980 [this value might be too low, and should be revised in later versions of the model- Ed]) was assumed to be the same as P/B, as no estimate of biomass was available to calculate fishing mortality. The Q/B ratio (5.9 yr-1) calculated in Appendix A Table A2 was assumed to be similar for both models. The diet in 1900 and 1450 was assumed to be similar to the 1985-87 diet (Lilly 2002). A catch of 5,000 tonnes was estimated for mackerel in Atlantic Canada in the early 1900s (Regier and McCracken 1975), and it was assumed that only about 1% of that catch was made in 2J3KLNO, as they are transient and mainly occur in the Gulf of St. Lawrence. Thus the catch in 1900 was estimated at 0.1 kgkm-2yr-1 (Regier and McCracken 1975) (Table 4). Mackerel also formed part of the diet of First Nations (Marshall 1996). Pre-contact catch of mackerel by First Nations is calculated at 0.004 kgkm-2yr-1 (Heymans 2002).  22-23) Demersal and bentho-pelagic piscivores (adult and juvenile)  The demersal and bentho-pelagic piscivores include white hake Urophycis tenuis, silver hake Merluccius bilinearis, monkfish Lophius americanus, sea ravens Hemitripterus americanus, cusk Brosme brosme, Atlantic halibut Hippoglossus hippoglossus, and saithe (?pollock?) Pollachius virens. Biomass was estimated for both models by assuming an ecotrophic efficiency of 95%. Natural mortality (0.1 yr-1 for adults and 0.15 yr-1 for juveniles) was assumed to be the same as P/B, as no estimate of biomass was available to calculate fishing mortality. Q/B ratios (1.1 yr-1 for adults and 1.7 yr-1 for juveniles) calculated in Appendix A Table A2 were assumed to be similar for both models. The diet in 1900 and 1450 was assumed to be similar to the 1985-87 diet (Lilly 2002). Ten thousand tonnes of pollock were caught in 1903 in Atlantic Canada (Regier and McCracken 1975) and we assume that 1% (0.2 kgkm-2yr-1, Table 4) of this catch was made in 2J3KLNO. It was assumed that, if any of the demersal and bentho-pelagic piscivores were caught by First Nations, that catch was too small to be represented in this model.  24-25) Large demersal feeders (adult and juvenile)  This group consists of a range of species that feed in the demersal domain, including haddock Melanogrammus aeglefinus, longfin hake Phycis chesteri, red hake Urophycis chuss, wolffish Anarhichas sp., grenadiers Coryphaenoides sp., eelpouts Lycodes sp., and batfishes. Biomass was estimated for both models by assuming an ecotrophic efficiency of 95%. Natural mortality (0.009 yr-1 for adults, obtained using the equation of Pauly, 1980 [this value may be too low and require future revision, Ed], and 0.15 yr-1 for juveniles) was assumed to be the same as P/B, as no estimate of biomass was available to calculate fishing mortality. Q/B ratio (1.4 yr-1 for adults and 2.1 yr-1 for juveniles) calculated in Appendix A Ecosystem Models of Newfoundland, Past and Present, Page 52  Table A2 was assumed to be similar for both models. The diet in 1900 and 1450 was assumed to be similar to the 1985-87 diet (Lilly 2002). The haddock fishery prior to 1945 was very low, but increased rapidly in the late 1940s in divisions 3NO (Anon. 1996b). The catch of haddock in 1903 was estimated at 7,000 tonnes (Regier and McCracken 1975), and it was assumed that only 10% of the haddock catches were made in 2J3KLNO (1.0 kgkm-2yr-1, Table 4). It was also assumed that if any of the demersal and bentho-pelagic piscivores were caught by First Nations that catch was too small to be represented in this model.  26) Other small demersals  The other small demersals group includes rocklings Enchelyopus sp., gunnel Pholis gunnellus, alligator fishes Ulcina olriki, Atlantic poachers Leptagonus decagonus, snakeblennies Lumpenus lampretaeformis, seasnails and shannies Leptoclinus sp., sculpin Myoxocephalus sp., searobins Prionotus sp., eelblennies Anisarchus sp., and wrymouth. Biomass was estimated for both models by assuming an ecotrophic efficiency of 95%. Natural mortality (0.56 yr-1) was assumed to be the same as P/B, while the Q/B ratio (4.5 yr-1) calculated in Appendix A Table A2 was assumed to be similar for both models. The diet in 1900 and 1450 was assumed to be similar to the 1985-87 diet (Lilly 2002). None of these species were reported in the diet of pre-contact First Nations or caught in 1900 and 1450.  27) Lumpfish  Lumpfish, Cyclopterus lumpus, are found in major concentrations on the St. Pierre bank off the southeast coast of Newfoundland (Garavis 1985 in Walsh et al. 2000). Biomass was estimated for both models by assuming an ecotrophic efficiency of 95%. Natural mortality (0.1 yr-1) was assumed to be the same as P/B, while the Q/B ratio (1.4 yr-1) calculated in Appendix A Table A2 was assumed to be similar for both models. The diet in 1900 and 1450 was assumed to be similar to the 1985-87 diet (Lilly 2002) and lumpfish was not reported in the diet of pre-contact First Nations or caught in 1900 and 1450.  28) Greenland cod  Greenland cod, Gadus ogac, is more closely related to Pacific cod than it is to Atlantic cod and is purported to be a northward and eastward extension of Pacific cod (Carr et al. 1999). Biomass was estimated for both models by assuming an ecotrophic efficiency of 95%. Natural mortality (0.1 yr-1) was assumed to be the same as P/B, while the Q/B ratio (1.3 yr-1) calculated in Appendix A, Table A2 was assumed to be similar for both models.  The diet in 1900 and 1450 was assumed to be similar their diet in the 1985-87 model (Lilly 2002) and Greenland cod was probably part of the diet of pre-contact First Nations. The catch by First Nations is calculated at 0.001 kgkm-2yr-1 (Heymans 2002).   29) Atlantic salmon  The earliest reference to Atlantic salmon in the Northeast Atlantic was made by Leif Ericson in 995 who suggested (Mowat 1984 p. 181) that on the coast of Newfoundland   There was no shortage of salmon there and these were larger salmon than they had ever seen before.  The rivers that were known to historically contain salmon in the study area include the Hamilton, Kenamu, North, Eagle, Paradise, Alexis, and Pinware Rivers in Labrador, and the Cloud, Cat Arm, Exploits, Gander, Southwest, Northeast, and Salmonier Rivers in Newfoundland (Dunfield 1985). The Exploits River was reported to provide good catches for First Nations despite the fact that only about 20% or no more than 850 square miles of its watershed was accessible (Dunfield 1985).   Although at least one researcher, Gordon W. Hewes, has claimed that the Amerindian salmon fishery was intense enough in some locations to depress the original stock of fish (Rostlund 1952), it is generally believed that native North Americans had no deleterious impact on the resource as a whole. There is even the suggestion that they may have enhanced it by inadvertently and unconsciously practicing good fishery management (Dunfield 1985).   Biomass was estimated for both models by assuming an ecotrophic efficiency of 95%. Natural mortality (0.1 yr-1) was assumed to be the same as P/B, while the Q/B ratio (1.3 yr-1) calculated in Appendix A Table A2 was assumed to be similar for both models. The diet in 1900 and 1450 was assumed to be similar to the 1985-87 diet (Lilly 2002).  The catch of salmon around 1900 is not known, but Dunfield (1985) gave catches between 1800 and 1867 of approximately 1.3 kgkm-2yr-1, which we use as an approximation of the catch in 1900 (Appendix B). The total accessible watershed area Page 53, Back to the Future on Canada?s East Coast   in North America over which salmon were distributed in pre-contact times comprised no less than a quarter of a million square miles of primeval territory, untouched by human influences except for the Amerindian who lived in harmony with it (Dunfield 1985). Rostlund (1952) calculated the aboriginal production of Atlantic salmon in the United States to be between 14 and 15 million pounds a year, or an average of 580 pounds per square mile in the occurrence area. Applying Rostlund?s base calculation to the total area of salmon occurrence in eastern North America, an estimated 145 million pounds per year is obtained (Dunfield 1985). Marshall (1996) suggested that salmon formed part of the Beothuk diet, and Marshall (pers. comm.) indicated that approximately 15% of their diet was comprised of salmon. Based on the above information Heymans (2002) estimated the salmon catch in pre-contact times at 55 tonnes or 0.1 kgkm-2yr-1.  30) Capelin  Carscadden et al. (2001) suggest that prior to 1970 capelin annually contributed in excess of 4.6 million tonnes to the diets of cod, seals and whales, while seabirds and finfish also forage extensively on capelin. Thus, at least 4.6 million tonnes of capelin is a lower limit to their annual production, and using their natural mortality of 0.6 yr-1 as an estimate of P/B in pre-contact times, we calculate a biomass of 16 tkm-2. This estimate would be a lower limit to the biomass of capelin, as it only included the consumption by cod, seals and whales, and not consumption by finfish, seabirds or other predators. This estimate, which we acknowledge to be very uncertain, was used for capelin biomass in the 1900s and 1500s models.   Carscadden et al. (2001) suggest that prior to the 1950s, 20-25,000 tonnes of capelin were taken annually in Newfoundland as bait, fertilizer and dog food. Inshore landings declined considerably until the early 1970s, when a directed offshore foreign fishery began. This fishery declined in the late 1970s and an inshore fishery for roe-bearing females started inshore again (Carscadden et al. 2001). In contrast, Vasconcellos et al. (2002b) suggest that the fishery prior to the 1960s, when the Japanese seiners arrived, was less than 10,000 tonnes per year. Regier and McCracken (1975) suggest a catch of 10,000 tonnes for the whole of Atlantic Canada. Considering that historically most of the distribution of capelin was in areas 2J3KLNO (Carscadden et al. 2001), we assume that approximately 80% of the Atlantic catch was made in 2J3KLNO. A catch of 0.016 tkm-2yr-1 was therefore estimated for 1900, while the catch during pre-contact was estimated at 0.017 kgkm-2yr-1 (Heymans 2002).  31) Sandlance  Sandlance Ammodytes dubius are abundant in coastal regions and over the shallow sandy areas of the continental shelf of the North Atlantic (Winters and Dalley 1988). In Newfoundland and Labrador waters, most sandlance occur on the plateau of Grand Bank, thus sandlance in 2J3KL are at the northerly end of their distribution (Bundy 2002). Sandlance was never commercially exploited and there are no catches or biomass estimates for the 1900 or pre-contact models. Thus biomass was estimated for both models by assuming an ecotrophic efficiency of 95%. The natural mortality of sandlance could not be calculated and was estimated by assuming a gross growth efficiency of 20%, while the Q/B ratio (4.9 yr-1) calculated in Appendix A Table A2 was assumed to be similar for both models. The diet in 1900 and 1450 was assumed to be similar to the 1985-87 diet (Lilly 2002).   32) Arctic cod  Arctic cod Boreogadus saida is an important forage species on the Labrador shelf and northeastern Newfoundland (Vasconcellos et al. 2002f). It was also never commercially exploited, although there has been a bycatch of Arctic cod (Lilly et al. 1994).  There are no reported catches or biomass estimates for the 1900 or pre-contact models, thus biomass was estimated for both models by assuming an ecotrophic efficiency of 95%. The natural mortality of sandlance could not be calculated, therefore P/B ratio was estimated from Q/B assuming a gross growth efficiency of 20%. Q/B ratio (4.9 yr-1) calculated in Appendix A Table A2 was assumed to be similar for both models. The diet in 1900 and 1450 was assumed to be similar to the 1985-87 diet (Lilly 2002).  33) Herring  Herring Clupea harengus, capelin, and mackerel were the traditional bait species for the cod fishery (Vasconcellos et al. 2002b), but herring landings rapidly increased from less than 4,000 tonnes a year to 140,000 tonnes after 1969 when a BC seiner was introduced to the fishery (Vasconcellos et al. 2002b). Biomass was estimated for both models by assuming an ecotrophic efficiency of 95%. Natural mortality (0.5 yr-1) was assumed to be the same as P/B, while the Q/B ratio (4.1 yr-1) calculated in Appendix A Table A2 was assumed to be similar for both models. The diet in 1900 and 1450 was Ecosystem Models of Newfoundland, Past and Present, Page 54  assumed to be similar to the 1985-87 diet (Lilly 2002). Regier and McCracken (1975) reported a catch of 4,000 tonnes of herring in Atlantic Canada in the early 1900s. Herring in Newfoundland is at the northern limit of its range, thus it was assumed that only about 25% (or 0.002 tkm-2yr-1, see Table 4) of the 4,000 tonnes caught in Atlantic Canada were taken in 2J3KLNO, while the catch during pre-contact was estimated at 0.004 kgkm-2yr-1 (Heymans 2002).  34) Transient pelagics  Transient pelagics include bluefin tuna Thunnus thynnus, swordfish Xiphias gladius, and sharks. Biomass for transient pelagics was estimated for both models by assuming an ecotrophic efficiency of 95%. Natural mortality (0.18 yr-1) was assumed to be the same as P/B, while the Q/B ratio (1.99 yr-1) calculated in Appendix A Table A2 was assumed to be similar for both models. The diet of transient pelagics was not well known, and was adapted from Bundy et al. (2000) by Heymans and Pitcher (this volume).   35) Small pelagics  Small pelagics were defined to include shad Alosa sapidissima, butterfish Peprilus triacanthus, argentine Argentina silus, juvenile mackerel, and Atlantic rainbow smelt Osmerus mordax mordax. Very little is known about these species, and the biomass was estimated for both models by assuming an ecotrophic efficiency of 95%. Natural mortality (0.6 yr-1) was assumed to be the same as P/B, while the Q/B ratio (5.3 yr-1) calculated in Appendix A Table A2 was assumed to be similar for both models. The diet in 1900 and 1450 was assumed to be similar to the 1985-87 diet (Lilly 2002). Smelts were important in the diet of the First Nations during pre-contact times. In Notre Dame Bay, the hundreds of tiny smelt bones found at Boyd?s Cove indicate that its inhabitants ate them regularly. The bones were preserved by the large quantities of clam and mussel shells that were discarded by the Beothuks at the same site making the soil less acidic (Pastore 1997). The catch of smelts by First Nations was assumed to be 0.001 kgkm-2yr-1 (Heymans 2002).  36) Mesopelagics  Mesopelagic species in the 2J3KLNO area include laternfishes Myctophidae, pearlsides Maurolicus muelleri, and barracudinas Paralepis elongata. This group is very poorly known and their biomass was estimated for both models by assuming an ecotrophic efficiency of 95%. Natural mortality (1.4 yr-1) was assumed to be the same as P/B, while the Q/B ratio (4.8 yr-1) calculated in Appendix A Table A2 was assumed to be similar for both models. The diet in 1900 and 1450 was assumed to be similar to the 1985-87 diet (Lilly 2002). Mesopelagics were not fished in 1900 or during pre-contact. Biomass estimates from ECOPATH balancing of 10.3 tkm-2 in 1900 and 11.1 tkm-2 in 1450 seem very high compared to the present day average biomass in this region of 1.1 tkm-2 (R. Watson, pers. comm.). However, these biomasses were needed to sustain the large quantities of higher trophic level species.  37-38) Squid (shortfin and Arctic squid)  Two species of squid are present in the area: shortfin squid Illex illecebrosus and Arctic squid Gonatus sp. Very little is known about Arctic squid other than it stays in the area throughout the year, while shortfin squid is highly migratory and spends only part of its time in the area (Bundy et al. 2000). No estimates of squid biomass were available for either the 1900s or the 1500s models, so the biomasses of both shortfin and Arctic squid were estimated by assuming ecotrophic efficiencies of 95% for both species in both models. Bundy et al. (2000) estimated P/B ratios for planktivorous and piscivorous small pelagics (Arctic and shortfin squid included) of 0.5 and 0.6 yr-1, respectively, and used a gross efficiency of 0.15 to calculate their Q/B ratios. Thus, a P/B of 0.5 yr-1 was used for Arctic squid and 0.6 yr-1 for shortfin squid in all four models, with their Q/B ratios calculated by using a GE of 0.15. The diet of shortfin squid was taken from Bundy et al. (2000) and adapted by Heymans and Pitcher (this volume), while Arctic squid was assumed to consume large and small zooplankton in the ratio of 1:1. Squid was not caught pre-contact or in 1900.  39-41) Large crustaceans (large crabs, small crabs, and lobster)  Large crabs (carapace width > 95 mm) include mostly adult snowcrabs Chioneocetes opilio and northern stone crabs Lithodes maja (Jonah crabs Cancer borealis and red crabs Geryon quinquedens do not really occur here). Small crabs include toad crabs Hyas sp., hermit crabs, rock crabs Cancer irroratus, and the juveniles of the large crabs. The American lobster Homarus americanus was split from other large crustaceans, as there is more information on TEK for that species. The biomasses of both large and small crabs and lobsters were estimated for both models by assuming an ecotrophic efficiency of 95%. The P/B (0.4 yr-1) and Q/B (4.4 yr-1) ratios used for large crustaceans in Bundy et al. (2000) Page 55, Back to the Future on Canada?s East Coast   were used for all three large crustacean groups in this model. The diet of crustaceans was obtained from Lovrich and Sainte-Marie (1997) and DFO (1996a and 1996b) and adapted for the 1980s and 1990s models (Heymans and Pitcher, this volume). The diet of lobster was assumed to be the same as that of large crabs.  Crabs were not caught in 1900, but small crabs did form part of the First Nations diet (Marshall 1996). Lobster of 16 and 25 pounds were caught and lobster was used as bait on a grand scale (Ennis et al. 1997). Landing statistics for Newfoundland start in 1874, and there was a peak catch of 7,938 tonnes in 1889 followed by a collapse and a three year closure in the mid 1920s (Ennis et al. 1997). Virtually everything caught was processed although lobsters were also used extensively as fertilizer in cottage farming (Ennis et al. 1997). The landings of lobster between 1900 and 1905 were approximately 4,000 tonnes (Ennis et al. 1997), and if we assume that the catch on the west coast (2J3KLNO) was approximately half the total, then the catch is estimated at about 0.004 tkm-2yr-1. Lobster also formed part of the First Nations diet (Marshall 1996), and Heymans (2002) calculates catch of small crabs and lobster by First Nations at approximately 0.011 kgkm-2yr-1 each.  42) Shrimp  Two species of shrimp are common in the 2J3KLNO area: northern shrimp Pandalus borealis, and Pandalus montagui (Parsons et al. 2000). The biomasses of shrimp in the 1900s and 1500s models were estimated by assuming an ecotrophic efficiency of 95%. The P/B (1.5 yr-1) and Q/B (9.7 yr-1) ratios and diet used by Bundy et al. (2000) for 1985-1987 were used in both models.  43-46) Benthos  The benthos were divided into echinoderms, polychaetes, bivalves (such as scallops) and other benthic invertebrates. The effects of climate change and ?fishing? on these groups should be taken into consideration when estimating the biomass of 1900s and 1500s models, but due to lack of information their biomass was estimated by assuming ecotrophic efficiencies of 95% each. The P/B and Q/B ratios for echinoderms, polychaetes, bivalves and other benthic invertebrates were obtained from Bundy et al. (2000) and they were all assumed to feed on detritus.   The resources of the sea, as well as the land, were essential to the Beothuks (Marshall 1996), and they were known to rely on clams, mussels, and other invertebrates (Pastore 1998). First Nations catches of bivalves and other invertebrates were estimated at 0.033 kgkm-2yr-1 and 0.022 kgkm-2yr-1 each (Heymans 2002).  47-48) Large and small zooplankton  The large zooplankton compartment includes cnidarians, ctenophores, pteropods, hyperiid amphipods, mysids, euphausiids, chaetognaths, tunicates and ichtyoplankton, while the small zooplankton consists of copepods, small tunicates and meroplankton. No biomass estimates were available for zooplankton for the 1900s or 1450s models, and it was estimated by assuming an ecotrophic efficiency of 95%. The P/B and Q/B ratios and diets obtained from Bundy et al. (2000) were used in both models.  49) Phytoplankton  No estimates of primary production or phytoplankton biomass were available for 1900 or 1450 and therefore the biomass was estimated by using an ecotrophic efficiency of 95% and a P/B ratio of 93.1 yr-1, obtained from Bundy et al. (2000).  50) Detritus  The detritus pool was recalculated from the formula for detritus obtained from Pauly et al. (1993):  log10 D = -2.41 + 0.954 log10 PP + 0.863 log10 E  where D = detritus standing stock in gCm-2 (grams of carbon per square metre), PP = primary productivity in gCm-2 yr-1) and E = euphotic depth (m). A value of 54.7 m was used for the euphotic zone depth (Bundy et al. 2000), and detritus pools of 393 and 296 tkm-2 were calculated for the 1450 and 1900 models respectively.   BALANCING THE MODELS: 1900-1905  The unbalanced model of 1900-1905 could not estimate a biomass for large crabs, as they are not consumed in the system. It also calculated an ecotrophic efficiency of 11.7 for juvenile cod, 7.4 for adult Greenland halibut, 75.7 for juvenile Greenland halibut and 3.9 for capelin. The estimate of juvenile American plaice was also calculated to be extremely large (17.7 tkm-2). To balance the model, it was therefore necessary to Ecosystem Models of Newfoundland, Past and Present, Page 56  re-examine the diets of all species that feed on capelin, halibut, juvenile cod and juvenile plaice.  Large crabs are not really prey for any species, and were also not caught until 1990, so we assume that the biomass of large crabs was similar to that obtained for the 1985-1987 model (86,345 tonnes from Bundy et al. (2000)) and use this biomass as a lower limit to the biomass in 1900 and 1450.  The main predators of juvenile American plaice are harp seals, large demersal bentho-pelagic piscivores and cannibals. We reduce the percentage of juvenile plaice in the diet of harp seals as well as the cannibalism by other juvenile plaice to 0.1%, and recalculate the diets of those groups to reduce the biomass of American plaice to 6.6 tkm-2.  To balance juvenile Greenland halibut we reduce the juvenile halibut in the diet of their main predators. The surplus is then re-distributed between all other prey species of the specific predator group. The proportion of juvenile Greenland halibut in the diet of their main predators was changed as follows:  !" Harp seals ? reduced to 0.01% !" Hooded seals ? reduced to 0.01% !" Cod (> 40 cm) ? reduced to 0.01% !" Cod (? 40 cm) ? reduced to 0.01% !" Removed juvenile Greenland halibut from the diet of juvenile American Plaice !" Adult American plaice ? reduced to 0.01% !" Adult Greenland halibut ? reduced to 0.01% !" Cannibalism ? reduced to 0.01% !" Large demersal feeders ? reduced to 0.01% !" Juvenile demersal feeders ? reduced to 0.01%  To balance the adult Greenland halibut, the percentages of adult halibut in the diet of hooded and harp seals (their only predators) were reduced to 0.1% each, and the diets of hooded and harp seals were recalculated to incorporate the surplus diet.  To balance juvenile cod, the percentages of juvenile cod in the diets of some of its predators were reduced, and the diets of these predators were recalculated to include the surplus consumption:  !" Cetaceans ? reduced to 0.1% !" Harp seals ? reduced to 0.1% !" Hooded seals ? reduced to 0.05% !" Adult cod ? reduced to 0.1% !" Removed juvenile cod from the diet of juvenile American plaice !" Adult Greenland halibut ? reduced to 0.1%  !" Redfish ? reduced to 0.1% !" Large demersal feeders ? reduced to 1% !" Juvenile demersal feeders ? reduced to 0.1% !" Transient pelagics ? reduced to 0.01% !" Shortfin squid ? reduced to 0.1%  To balance capelin, the percentages of capelin in the diets of some of its predators were reduced, and the diets of these predators were recalculated to include the surplus consumption:  !" Cetaceans ? reduced to 10% !" Harp seals ? reduced to 5% !" Adult cod ? reduced to 9% !" Juvenile cod ? reduced to 10% !" Adult American plaice ? reduced to 5% !" Juvenile American plaice ? reduced to 0.1% !" Arctic cod ? reduced to 1% !" Shortfin squid ? reduced to 1%  The ecotrophic efficiency of detritus was calculated at 1.4, and to balance the detritus the ecotrophic efficiency of phytoplankton was assumed to be 50% (instead of 95%). This value is closer to the 34% estimated for the 1985-87 model by Bundy et al. (2000), and calculates a phytoplankton biomass of 64.4 tkm-2, and recalculates the detritus pool to 546.6 tkm-2.  Hence we effectively assume that primary production in the past was about 2 times higher than in the 1980s and 1990s, which is what seems to be needed to feed all the top predators that we suspect were present. Clearly, this is a controversial finding and could be adjusted in future versions of the model.  Modifications to the balanced model  The balanced model was subsequently modified to include changes made to the bird population. These changes include the inclusion of shearwaters and fulmars in the piscivorous birds rather than planktivorous birds, and the summation of the resident and breeding populations vs. averaging these two populations. The new biomass estimates increased the ecotrophic efficiency of capelin to 1.009. The percentage of capelin in the diet of piscivorous birds was then reduced to 70% (from 78%), with the rest of its diet being recalculated to balance the model.  The biomass of lobster was estimated at 0.08 tkm-2 for the 1900 model (Tony Pitcher, Fisheries Centre, pers. comm.) and the predators of the following three species were expanded, as they were under-represented in the model: Page 57, Back to the Future on Canada?s East Coast    1. The predators of salmon were expanded to include cetaceans (0.0001), grey seals (0.002), piscivorous birds (0.001), skates (0.001) and transient pelagics (0.001).  2. The predators of large crabs were expanded to include grey, harp and hooded seals as well as large cod (all 0.001). 3. The predators of lobster were expanded to include walrus, large cod, skates (all 0.0001), large demersal piscivores (0.001) and other large demersal species (0.0001).   These new changes increased the ecotrophic efficiency of capelin to 1.1, and the percentage of capelin in the diet of Arctic cod was subsequently decreased to 1%, which increased the ecotrophic efficiency of juvenile cod to 1.1. The percentage of juvenile cod in the diet of skates was then reduced to 1% and cannibalism by juvenile cod was reduced to 1% (from 3%) to balance the model. The parameters of the balanced model of 1900-1905 are given in Appendix C.   BALANCING THE MODELS: 1450  The unbalanced model of 1450 could not estimate a biomass for large crabs, as they are not consumed in the system. It also calculated an ecotrophic efficiency of 34.9 for juvenile cod, 18.6 for adult Greenland halibut, 160.9 for juvenile Greenland halibut and 7.5 for capelin. The estimate of juvenile American plaice was also extremely large (41.9 tkm-2) and likely unrealistic. The compartments that were unbalanced were similar to those that were unbalanced in the 1900 model, so we used the balanced diet obtained from the 1900 model and included the biomass of large crabs (0.17 tkm-2) similar to the 1900 model. The 1900 diet improved the balancing, as the ecotrophic efficiency of cod was reduced to 1.4, that of adult halibut to 1.1 and that of capelin to 1.5. To balance these compartments, it was therefore necessary to re-examine the diets of all species that feed on capelin, adult halibut and juvenile cod.  To balance capelin the percentage of capelin in the diet of piscivorous birds was severely reduced, to 1% (i.e. we are assuming that capelin was not important in the diet of piscivorous birds), and the rest of the diet of piscivorous birds was increased to incorporate the surplus consumption.  To balance juvenile cod, the juvenile cod in the diet of piscivorous birds was reduced to 0.01% and in the diet of grey seals it was reduced to 1%, while the rest of the diet of piscivorous birds and grey seals was increased to incorporate the surplus consumption.  To balance adult Greenland halibut, the proportion it supplies to the diet of harp seals was further reduced to 0.05 % and the rest of the diet of harp seals was increased to incorporate the surplus consumption.  The ecotrophic efficiency of detritus was calculated at 1.3, and to balance the detritus the ecotrophic efficiency of phytoplankton was assumed to be 50% (instead of 95%). This value is closer to the 34% estimated for the 1985-87 model by Bundy et al. (2000), and calculates a phytoplankton biomass of 86.7 tkm-2 and a detritus pool of 726 tkm-2.  Modifications to the balanced model  Birds  This balanced model was subsequently modified to include changes made to the bird population. These changes include the inclusion of shearwaters and fulmars in the piscivorous birds rather than planktivorous birds, and the summation of the resident and breeding populations vs. averaging these two populations. The new biomass estimates increased the ecotrophic efficiency of juvenile cod to 1.179, that of juvenile Greenland halibut to 1.058 and that of capelin to 1.441.  To balance capelin, the percentage of capelin in the diets of piscivorous birds and small bentho-pelagic demersals was reduced to 0.01% each. In the diet of other small demersals the capelin was reduced to 0.5%, and in the diet of Greenland cod it was reduced to 5%. Juvenile cod was balanced by reducing the percentage that it contributes to the diet of juvenile bentho-pelagic demersals, other small demersals and shortfin squid, to 0.01% respectively. Juvenile Greenland halibut is balanced by reducing the percentage it contributes to the diet of juvenile bentho-pelagic demersals to 0.001%.  Cetaceans  The biomass of cetaceans in 1450 was estimated by the model. However, the value estimated (0.042 tkm-?) was much lower than the 0.5 tkm-? assumed for 1900. The parameters of cetaceans were investigated, and it was assumed that the P/B and Q/B of cetaceans would have been lower in 1450, due to the change in species composition from larger, more planktivorous Ecosystem Models of Newfoundland, Past and Present, Page 58  baleen whales to smaller, faster-growing toothed whales. Thus, the P/B of cetaceans was reduced to 0.05 yr-1 and the Q/B to 9 yr-1 (these values are higher than those of toothed whales in Hecate Strait, but lower than the values given for the present-day Newfoundland models). The ecotrophic efficiency was also reduced from 0.95 to 0.15, as by definition very little of the unexplained mortality of cetaceans would be accounted for. This recalculates the biomass of cetaceans to 0.53 tkm-?, but increases the ecotrophic efficiency of juvenile cod and capelin to > 100%.   To rebalance the model the percentages of small cod and capelin in the diet of cetaceans were reduced to 0.001% and 1% respectively, while the percentage of large zooplankton was increased to 20%. This reduced the ecotrophic efficiency of juvenile cod and capelin, but not enough. To balance capelin, the percentages of capelin in the diets of Arctic cod and mesopelagics were reduced to 0.1% each. To balance juvenile cod, the percentage of juvenile cod in the diet of redfish was reduced to 0.01%.   Lobster, salmon and large crabs  The biomasses of these three compartments were very low in the balanced model and thus the predators of these three species were expanded, to increase the required biomass for balancing:  !" The predators of salmon were expanded to include cetaceans (1%), grey seals (0.2%), piscivorous birds (0.02%), skates (1%) and transient pelagics (1%). !" The predators of large crabs were expanded to include grey, harp and hooded seals, large cod (all 0.1%) as well as transient pelagics (1%). !" The predators of lobster were expanded to include walrus (0.1%), large cod (5%), skates (0.1%), large demersal piscivores (0.1%) and other large demersal species (0.1%).  Changed due to large biomass  When the model was balanced, the biomass estimates of witch flounder, redfish, juvenile demersal bentho-pelagic predators, juvenile demersal feeders and small crabs were extremely high (above 40 tkm-? each). To reduce these biomass estimates (all from ECOPATH), some changes were made to their contributions to predators:  !" The percentages of redfish in the diet of hooded seals and adult Greenland halibut were reduced from 20% to 1%, and from 30% to 10% respectively. !" The 14.4% of witch flounder in the diet of harp seals was divided between yellowtail flounder (5%), witch flounder (5%) and winter flounder (4.4%). !" The percentages of juvenile demersal bentho-pelagic predators and juvenile demersal feeders in the diet of piscivorous birds were both reduced to 0.5% from 1.8%. !" The small crabs in the diet of adult cod were reduced from 12% to 6% and the remaining 6% were assumed to be juvenile lobster. Similarly, the small crabs in the diet of juvenile demersal bentho-pelagic predators were reduced from 6% to 3% with the remaining 3% being taken from juvenile lobster, and the 10% in the diet of juvenile demersal feeders were assumed to be 5% each small crabs and juvenile lobster.  These changes improved the estimated biomass of redfish (14 tkm-?), witch flounder (8 tkm-? ), juvenile demersal bentho-pelagic predators (20 tkm-?), juvenile demersal feeders (23 tkm-?) and small crabs (25 tkm-?) to within reasonable limits. The parameters of the balanced model of 1450 are given in Appendix D.   CONCLUSIONS  These models represent our current best attempt at reconstructing these long-past ecosystems. The models may be thought of as an abstract version of what the Newfoundland and southern Labrador ecosystem could have looked like, and if visualized, might resemble an artwork by Picasso where all neccessary components of the human form are present, but are misplaced.   Some major features of the models are debatable. For example, our assumption of 95% ecotrophic efficiency for groups that were not heavily fished might be questioned by some. Our argument is that in a mature, very bio-diverse and relatively unfished ecosystem, most trophic flows will likely be accounted for within the system. Others have argued that ecotrophic efficiency would be low in unfished systems. Secondly, our calculation of phytoplankton production as higher than the present day can clearly be questioned, even if the fertilization effect of large numbers of marine mammals and more large animals dying of old age and contributing to the detritus pool could have enhanced primary production.  Some details of the models can undoubtedly be improved. For example, we need to check the Page 59, Back to the Future on Canada?s East Coast   apparently high biomass of mesopelagics, which were unfished in these past times, relative to densities in the present day. Aside from such details, without better information on the biomasses and diets of the groups in the ecosystem ? which, for the ancient past, is unlikely to be forthcoming ? a substantially more accurate model is not possible. However, there may be some shortcuts to obtaining improved estimates for major biomass pools from comparative analyses of many different marine ecosystems.   These static mass-balance ECOPATH models will be used as baselines for dynamic exploration using ECOSIM. Policy explorations in Back to the Future aim to determine what fisheries could be sustained by the Newfoundland marine ecosystem if it were restored to its state in 1900 or 1450.    ACKNOWLEDGEMENTS  The authors wish to thank George Lilly from DFO in St. John?s, Newfoundland for his help in reconstructing the diets of all groundfish species and Alida Bundy (BIO, Halifax, NS) for her contribution to the model breakdown. Garry Stenson (DFO, St. John?s, Newfoundland) is acknowledged for his help with reconstructing the catches of seals in 1900, and for general help with the models. Ingeborg Marshall (St. John?s, Newfoundland) and Peter Pope (MUN, St. John?s, Newfoundland) are acknowledged for their help in reconstructing the First Nations catches. Reg Watson (FC, UBC) kindly extracted the mesopelagic data from the Sea Around Us database. Acknowledgement is also given to Bill Montevecchi, Barb Neis, Ransom Myers, Jeff Hutchings and Jon Lien for information, data and discussions on the construction of the model.   REFERENCES  Allen, G. M. 1942. Family Odobenidae: Walruses. 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A walrus in the Bay of Fundy; the first record. The Canadian Field-Naturalist 65:61-63.  Page 63, Back to the Future on Canada?s East Coast  APPENDICES  APPENDIX A:     MODEL GROUPS AND SPECIES ? M AND P/B ESTIMATES The P/B and Q/B ratios of all fish species were calculated by using empirical formulas obtained from Palomares and Pauly (1998). The formula used for M was: logM = 0.0066 - (0.279  Log10(Loo)) + (0.65431Log10(k)) + (0.4631 Log10(T)) while the Q/B ratio was estimated from the formula: log Q/B = 7.964 ? 0.204 log Woo ? 1.965T? + 0.083A + 0.532h + 0.398d  Woo was estimated from the length-weight formula W(g) = a * Lb and the values used for the growth parameters k and  Loo (cm), the temperature T (oC), a and b were obtained from FishBase 2000 (Froese and Pauly 2000) and references therein.  ?h? was 1 for herbivores and 0 for all other groups, while ?d? was 1 for detritivores and 0 for all other groups. 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 A1. M estimated for all fish compartments. Species K Loo (cm) T (?C) Adult M Juvenile M FishBase Ref Cod 0.07 176 7 0.1037 0.155 934 American plaice (3L) 0.067 72.5 2 0.0723  American plaice (3N) 0.099 72.90 2 0.0931  American plaice    0.0827 0.123 Greenland halibut 0.024 271.82 2 0.0255  Greenland halibut 0.032 253.71 2 0.0314  Greenland halibut 0.03 206.67 2 0.0319  Greenland halibut 0.027 264.72 2 0.0278  Greenland halibut 0.026 256.09 2 0.0274  Greenland halibut 0.025 268.81 2 0.0263  Greenland halibut 0.022 293.44 2 0.0236  Greenland halibut 0.024 268.64 2 0.0256  Greenland halibut 0.021 284.63 2 0.0231  Greenland halibut 0.023 280.52 2 0.0246  Greenland halibut 0.024 249.05 2 0.0262  Greenland halibut 0.022 278.21 2 0.0240  Greenland halibut    0.0264 0.0397 (Bowering and Nedreaas 2001)            Yellowtail flounder 0.335 50 4 0.3167  1801 Witch flounder 0.2 43.7 4 0.2346  3992 Winter flounder 0.4 44 2 0.2674  1726 Little skate 0.35 52.7 2 0.2330  Spiny dogfish 0.106 101 7 0.1589  Redfish female 0.058 52.5 2 0.0719  Redfish male 0.151 32.7 2 0.1535  Average redfish  42.6  0.1127  Mackerel 0.36 42.9 10 0.5296  1212 Silver hake 0.28 62.2 2 0.1922  5841 White hake female 0.106 136 2 0.0818  8900 White hake male 0.218 84 2 0.1501  8900 Atlantic halibut female 0.02 250 2 0.0232  1103 Atlantic halibut male 0.04 170 2 0.0406  1103 Cusk 0.08 89 2 0.0766  27397 Pollock 0.1 111 4.4 0.1201  5760 Average Bentho-pelagic piscivores    0.0978 0.1457 Haddock 0.28 73 7 0.3284  953 Red hake 0.19 60.2 10 0.3172  5760 Atlantic wolffish 0.098 150 3 0.091 0.137 731 Northern wolffish male 0.044 167 3 0.052 0.079 731 Northern wolffish female 0.043 158 3 0.052 0.079 731 Spotted wolffish 0.061 181 3 0.064 0.095 731 Female round-nose grenadier 0.099 110 8 0.1578  312 Male round-nose grenadier 0.082 105 8 0.1413  312 Ocean pout 0.076 91 10 0.1552  1362 American eel 0.13 155.3 10 0.1899  Average demersals    0.1550 0.2324 Ecosystem Models of Newfoundland, Past and Present, Page 64  Goat sculpin female 0.358 32.3 8 0.5151  865 Goat sculpin male 0.758 19.6 8 0.9673  865 Longhorn sculpin 0.72 30 8 0.8305  869 Arctic staghorn sculpin male 0.383 14 5.4 0.5666  33314 Arctic staghorn sculpin female 0.338 11 5.4 0.5585  33314 Fourbeard rockling 0.2 36 8 0.3414  27396 Snake blenny 0.205 47.6 2 0.1689  1282 Average small demersals    0.5640  Lumpfish 0.12 55 2 0.1143  872 Greenland cod 0.19 79.5 1 0.1010  Salmon 0.13 38.9 10 0.2795  7479 Capelin male 0.48 20 5 0.5738  1080 Capelin female 0.48 19 5 0.5820  1080 Average capelin    0.5779  Arctic cod 0.67 22 3.3 0.5733  796 Herring 0.33 33.5 9 0.5105  5871 Bluefin tuna 0.12 313 10 0.1482  5795 Swordfish 0.23 365 10 0.2174  7174 Transient pelagics    0.1828  American butterfish 0.8 18.3 10 1.1326  12001 American shad 0.13 78.5 10 0.2298  Alewife female 0.47 19.9 10 0.7812  4513 Alewife male 0.484 19.4 10 0.8020  4586 Greater argentine 0.12 50.7 10 0.2463  737 Small pelagics    0.6384  Glacier lanternfish 0.36 8.5 4 0.5442  1058 Small-fin lanternfish 3.65 3.3 4 3.2260  4882 Spotted lanternfish 0.32 9 4 0.4959  1062 Jewel lanternfish  31.5 4   Mesopelagics    1.4220  Page 65, Back to the Future on Canada?s East Coast   Table A2.  Calculations of Q/B for all fish compartments. Species Loo a b Temp.  (Kelvin) Woo (g) h d Aspect ratio Q/B Juvenile Q/B FishBase reference Cod 176.00 0.0068 3.1010 3.5695 62494 0 0 0.8 1.0913 1.6370  American plaice (3L) 72.50 0.0011 3.3450 3.6344 1854 0 0 1.3 1.8350   American plaice (3N) 72.90 0.0044 3.2040 3.6344 4089 0 0 1.3 1.5616   American Plaice         1.6983 2.5474  Greenland halibut male 284.63 0.0039 3.2060 3.6344 143712 0 0 1.3 1.2084   Greenland halibut female 280.52 0.0025 3.3280 3.6344 16312 0 0 1.3 1.1776   Greenland  halibut 264.69        1.1930 1.7895  Yellowtail flounder 50.00   3.5952    0.7 3.2710   Witch flounder 43.70 0.0017 3.3900 3.6082 619 0 0 0.7 2.3045  268 Winter flounder 44.00 0.0213 3.0000 3.6344 1814 0 0 0.7 1.6436  6323 Little skate 52.70 0.0078 2.9720 3.6344 1020 0 0 0.5 1.7789  2753 Spiny dogfish 101.00   3.5695 4156 0 0 1.6 2.2105   Redfish 42.60 0.0115 3.1370 3.6610 1486 0 0 1.3 1.7019  268 Mackerel 42.90 0.0046 3.1800 3.5317 716 0 0 4 5.9404   Silver hake 62.20 0.0107 3.0090 3.6344 2672 0 0 0.9 1.5778  12286 White hake female 136.00 0.0043 3.1470 3.6344 22373 0 0 0.9 1.0228  8900 White hake male 84.00 0.0040 3.1720 3.6344 5080 0 0 0.9 1.3840  8900 Atlantic halibut female 250.00 0.0276 2.9530 3.6344 332680 0 0 0.9 0.5897  1105 Atlantic halibut  male 170.00 0.0130 3.2490 3.6344 229442 0 0 0.9 0.6362  1105 Cusk 89.00 0.0132 3.0000 3.6344 9338 0 0 0.9 1.2224   Pollock 111.00 0.0077 3.0480 3.6030 13219 0 0 0.9 1.3127  6014 Bentho-pelagic piscivores         1.1065 1.6598  Haddock 73.00 0.0132 2.9010 3.5695 3358 0 0 0.9 2.0197  6014 Red hake 60.20 0.0125 3.0000 3.5317 2717 0 0 0.9 2.5024   Atlantic wolffish 150.00 0.0780 2.6150 3.6212 38245 0 0 1 0.9919  719 Northern wolffish  158.00 0.0068 3.6410 3.6212 683305 0 0 1 0.5509  719 Spotted wolffish 181.00 0.0017 3.3990 3.6212 81167 0 0 1 0.8507  719 Roundnose grenadier 110.00 0.7320 2.5870 3.5568 139828 0 0 0.5 0.9261  27581 American eel 155.30 0.0018 3.0350 3.5317 7999 0 0 0.5 1.8599  3989 Large Demersals         1.3859 2.0789  Goat sculpin female 32.30 0.0126 3.1240 3.5568 653 0 0 1.3 3.2245   Goat sculpin male 19.60 0.0126 3.1240 3.5568 137 0 0 1.3 4.4333   Arctic staghorn sculpin male 14.00 0.0057 3.2900 3.5900 34 0 0 1.3 5.0771  33314 Arctic sculpin female 11.00 0.0057 3.2900 3.5900 15 0 0 1.3 5.9691  33314 Fourbeard rockling 36.00 0.0035 3.1060 3.5568 239 0 0 0.9 3.6682   Small demersals         4.4744   Lumpfish 55.00 0.0587 2.9390 3.6344 7648 0 0 1.3 1.3743   Greenland cod 79.50 0.0117 3.0000 3.6476 5879 0 0 0.9 1.2652  7275 Salmon 38.90 0.0116 3.0000 3.5317 683 0 0 2 4.0928  682 Capelin male 20.00 0.0015 3.4100 3.5952 41 0 0 1.3 4.7686   Capelin female 19.00 0.0022 3.2500 3.5952 32 0 0 1.3 5.0315   Capelin         4.9001   Sandlance female 23.20 0.0014 3.0850 3.5952 23 0 0 1.3 5.3728  4667 Sandlance male 23.20 0.0010 3.4910 3.5952 58 0 0 1.3 4.4352  4667 Sandlance         4.9040   Arctic cod 22.00 0.0054 3.0560 3.6173 68 0 0 0.9 3.6009  33278 Herring 33.50 0.0088 3.0330 3.5442 373 0 0 1.7 4.1310   Bluefin tuna 313.00 0.0196 3.0090 3.5317 632920 0 0 5.5 1.9826  26805 Swordfish 365.00 0.0027 3.3000 3.5317 773634 0 0 5.8 2.0154  11991 Transient pelagics         1.9990   American butterfish 18.30 0.0056 3.2600 3.5317 73 0 0 1.9 6.3344  12035 American shad 78.50 0.0065 2.9590 3.5317 2629 0 0 1.9 3.0498  3762 Alewife female 19.90 0.0076 3.0100 3.5317 62 0 0 2.1 6.8158  4513 Alewife male 19.40 0.0126 2.9100 3.5317 70 0 0 2.1 6.6305  4513 Greater argentine 50.70 0.0039 3.2030 3.5317 1128 0 0 1.9 3.6246   Small pelagics         5.2910   Spotted lanternfish 9.00 0.0080 3.0000 3.6082 6 0 0 1 6.3145   Jewel lanternfish 31.50 0.0051 2.9800 3.6082 149 0 0 1 3.2642  26178 Mesopelagics         4.7894   Ecosystem Models of Newfoundland, Past and Present, Page 66  APPENDIX B:   EXPORTS OF SALMON FROM NEWFOUNDLAND  Export of salmon from Newfoundland. A tierce contained 214 kg round weight, a barrel 143 kg, there was a 48% weight loss for a packages (from Dunfield 1985). Year # tierces barrels Packages cwt. Weight (t) Export (kgkm-2yr-1) 1801 1688    362 0.731 1802       1803 3709    795 1.606 1804 3739    801 1.619 1805 1916    411 0.829 1806 2040    437 0.883 1807 3469    743 1.502 1808 3272    701 1.417 1809 4064    871 1.759 1810 5747    1232 2.488 1811 2694    577 1.166 1812 3831    821 1.659 1813 3737    801 1.618 1814 3425    734 1.483 1815 2752    590 1.191 1816 2659    570 1.151 1817 2858    612 1.237 1818 1663    356 0.72 1819 2125    455 0.92 1820 1808    387 0.783 1821 1916    411 0.829 1822 2650    568 1.147 1823 2257    484 0.977 1824 2546    546 1.102 1825 3127    670 1.354 1826 3204    687 1.387 1827 2889    619 1.251 1828 2330.5    499 1.009 1829 2795    599 1.21 1830 4322    926 1.871 1831 3710    795 1.606 1832 3302.5    708 1.43 1833 2901    622 1.256 1834 2625    563 1.136 1835 2477    531 1.072 1836 2130    456 0.922 1837 2262    485 0.979 1838 4408    945 1.908 1839 2922    626 1.265 1840 3396    728 1.47 1841 3642    780 1.577 1842 4715    1010 2.041 1843 4058    870 1.757 1844 3753    804 1.625 1845 3545    760 1.535 1846  5201   743 1.501 1847  4917   702 1.419 1848  3822   546 1.103 1849  5911   844 1.706 1850 1933 1700   657 1.327 1851 2965 1613 18  867 1.751 1852 2899 765   731 1.476 1853 2840 1626 1387  911 1.841 1854 2601 602 167  652 1.317 1855 2481 647 176  633 1.279 1856 1216 1156 190  435 0.88 1857 2486 815 46  652 1.316 1858 2726  109  590 1.191 1859 3716  29  798 1.612 1860 3963   51 849 1.716 1861 2924    627 1.266 1862 4227   14 906 1.83 1863 3179 1767  46 934 1.886 1864 1765 1257  11.5 558 1.127 1865 2418 1598  103 746 1.508 1866 2917 977 873  809 1.634 1867 2472 1867 516  823 1.662 Average      1.37 Page 67, Back to the Future on Canada?s East Coast   APPENDIX C:    BALANCED MODEL AND DIET MATRIX 1900-1905  Input parameters of the balanced 1900-1905 model (values in bold are estimated by ECOPATH). Group name Trophic level Biomass P/B Q/B EE P/Q Walrus 3.31 0.000001 0.060 16.846 0.000 0.004 Cetaceans 4.1 0.502 0.100 11.790 0.880 0.008 Grey seals 4.4 0.000001 0.060 15.000 0.281 0.004 Harp Seals 4.13 0.591 0.102 17.412 0.274 0.006 Hooded Seals 4.42 0.102 0.109 13.100 0.169 0.008 Ducks 3 0.000453 0.250 54.750 0.009 0.005 Piscivorous Birds 4.28 0.027 0.250 54.750 0.215 0.005 Planktivorous Birds 3.53 0.006 0.250 54.750 0.009 0.005 Adult Cod > 40cm 3.95 8.162 0.198 1.091 0.535 0.182 Juv Cod ? 40 cm 3.63 1.360 0.155 1.637 0.918 0.095 American plaice >35cm 3.45 2.745 0.083 1.698 0.950 0.049 American plaice ?35cm 3.37 13.849 0.124 2.547 0.950 0.049 Greenland halibut >65cm 4.38 0.929 0.030 1.193 0.548 0.025 Greenland halibut ? 65 cm 4.22 0.283 0.040 1.789 0.746 0.022 Yellowtail Flounders 3.12 2.391 0.317 3.271 0.950 0.097 Witch flounder 3.02 7.790 0.235 2.304 0.950 0.102 Winter flounder 3.08 0.191 0.267 1.644 0.950 0.163 Skates 4.23 0.469 0.233 1.779 0.800 0.131 Dogfish 4 0.078 0.159 2.210 0.950 0.072 Redfish 3.68 20.586 0.113 1.702 0.950 0.066 Transient Mackerel ( >29cm) 3.85 0.002 0.530 5.940 0.950 0.089 Large demersal piscivores (> 40 cm) 4.29 1.336 0.098 1.107 0.950 0.088 Large demersal piscivores (? 40cm) 3.93 20.007 0.147 1.660 0.950 0.088 Large Demersal Feeders (> 30cm) 3.36 1.958 0.155 1.386 0.950 0.112 Small demersal feeders 3.28 20.425 0.232 2.079 0.950 0.112 Other small demersals 3.11 7.899 0.564 4.474 0.950 0.126 Lumpfish 3.59 0.586 0.114 1.374 0.950 0.083 Greenland cod 4.04 0.572 0.101 1.265 0.950 0.080 Salmon 4.26 0.034 0.279 4.093 0.950 0.068 Capelin 3.26 16.080 0.578 4.900 0.931 0.118 Sandlance 3.2 22.607 0.981 4.904 0.950 0.200 Arctic cod 3.38 9.228 0.573 3.601 0.950 0.159 Herring 3.29 6.023 0.510 4.131 0.950 0.124 Transient Pelagics 4.08 0.115 0.183 1.999 0.950 0.091 Small Pelagics 3.42 2.006 0.638 5.291 0.950 0.121 Small Mesopelagics 3.38 10.353 1.422 4.789 0.950 0.297 Shortfin squid 3.96 3.315 0.600 4.000 0.950 0.150 Arctic Squid 3.28 8.859 0.500 3.333 0.950 0.150 Large Crabs (>95 cm) 2.92 0.174 0.380 4.420 0.310 0.086 Small Crabs  (? 95 cm) 3.08 27.270 0.380 4.420 0.950 0.086 Lobster 2.93 0.080 0.380 4.420 0.222 0.086 Shrimp 2.46 14.405 1.450 9.670 0.950 0.150 Echinoderms 2 61.087 0.600 6.670 0.950 0.090 Polychaetes 2 25.228 2.000 6.330 0.950 0.316 Bivalves 2 66.225 0.570 22.220 0.950 0.026 Other benthic invertebrates 2 28.586 2.500 12.500 0.950 0.200 Large zooplankton 2.56 93.738 3.433 13.732 0.950 0.250 Small zooplankton 2 107.043 8.400 28.000 0.950 0.300 Phytoplankton 1 74.873 93.100 - 0.500 - Detritus 1 546.612 - - 0.514 -  Ecosystem Models of Newfoundland, Past and Present, Page 68  Balanced diet in 1900-1905:  1 2 3 4 5 6 7 7 8 9 10 11 12 13 14 15 1                 2                 3 0.0010               0.0010 4 0.0010               0.0010 5 0.0010               0.0010 6                 7    0.0001             8                 9   0.0999 0.0060 0.0240            10  0.0001 0.0909 0.0010 0.0010  0.0080  0.0010 0.0010 0.0001  0.0010 0.0087   11    0.0210             12 0.0100  0.0070 0.0010     0.0430 0.0005 0.0012 0.0011 0.0013   0.0100 13    0.0010 0.0010            14   0.0010 0.0001 0.0001    0.0001 0.0001 0.0001  0.0001 0.0001   15 0.0043  0.0070 0.0001 0.0349    0.0020  0.0001 0.0124    0.0043 16 0.0043  0.0300 0.1437 0.1307    0.0002  0.0001  0.0030   0.0043 17 0.0043  0.0300 0.0002 0.0349           0.0043 18   0.0040 0.0000     0.0005    0.0013    19  0.0020               20   0.0060 0.0060 0.2026    0.0210 0.0002  0.0013 0.3216    21   0.0050    0.0005          22  0.0209               23 0.0020 0.0209 0.0410 0.0000   0.0051  0.0002 0.0002      0.0020 24  0.0209  0.0130 0.0220            25 0.0100 0.0209 0.0260 0.0120 0.0659  0.0051  0.0621 0.0079 0.0059 0.0089 0.0873 0.0004  0.0100 26 0.0160  0.0030 0.0260   0.0051  0.0360 0.0296 0.0066 0.0230 0.0198 0.0072  0.0160 27  0.0080 0.0150    0.0051  0.0010        28 0.0020 0.0030 0.0040 0.0020   0.0051  0.0010       0.0020 29  0.0010 0.0020    0.0005          30 0.0440 0.1017 0.0120 0.0529 0.0100  0.7081  0.0500 0.1137 0.0534 0.0011 0.4801 0.8382 0.0394 0.0440 31  0.0718 0.4505 0.2885   0.0797  0.2642 0.0487 0.2276 0.1417  0.0002 0.0404  32  0.2044 0.0020 0.2206 0.1227  0.0957  0.0540 0.0508 0.0008 0.0058 0.0335 0.0501   33  0.0748 0.0749 0.0200 0.1188  0.0154  0.0120 0.0251       34   0.0050  0.0140  0.0005      0.0005    35  0.0758 0.0430 0.0000 0.0489  0.0085          36  0.0409 0.0100 0.0010   0.0239  0.0040 0.0008   0.0112 0.0085   37   0.0300 0.0150 0.0838  0.0085  0.0030    0.0008    38  0.0748  0.0010 0.0838  0.0154  0.0060 0.0030 0.0008 0.0002 0.0157 0.0313   39   0.0010 0.0010 0.0010    0.0010        40 0.1200   0.0003     0.1241 0.0372 0.0656 0.0390    0.1200 41 0.0001        0.0001       0.0001 42 0.1200   0.1368   0.0096  0.0921 0.1240 0.0039 0.0199 0.0167 0.0223  0.1200 43 0.0500        0.0110 0.0003 0.4015 0.1751  0.0001 0.0734 0.0500 44 0.1000        0.0150 0.0268 0.0223 0.1732   0.4043 0.1000 45 0.3000   0.0000  0.9000   0.0490 0.0074 0.0808 0.0340   0.0298 0.3000 46 0.2000   0.0000  0.1000   0.0300 0.2191 0.1013 0.2189 0.0024 0.0035 0.3702 0.2000 47  0.1436  0.0299    0.9569 0.1161 0.3033 0.0278 0.1445 0.0039 0.0293 0.0426  48 0.0100 0.1146      0.0431  0.0003  0.0002    0.0100 49                 50                  Page 69, Back to the Future on Canada?s East Coast   1900-1905 diet continued?  16 17 18 19 20 21 22 23 24 25 26 27 28 29 1               2               3               4               5               6               7               8               9               10   0.0102 0.0200 0.0010  0.0104 0.0010 0.0017 0.0009    0.0022 11               12   0.0010    0.0707 0.0320 0.0010 0.0005     13               14   0.0010 0.0025   0.0001 0.0001      0.0011 15       0.0119 0.0060       16   0.0051    0.0040 0.0020       17               18       0.0040 0.0020 0.0003 0.0002     19               20   0.1391 0.0530 0.0070  0.0243 0.0130 0.0185 0.0093     21               22               23   0.0429 0.0125   0.1363 0.0721 0.0003 0.0002     24               25   0.1145 0.0350 0.0010  0.1543 0.0811 0.0004 0.0002 0.0020  0.0100  26 0.0090 0.0710 0.0286 0.0100   0.1070 0.0561 0.0013 0.0007 0.0080  0.2000  27               28               29   0.0010            30   0.1278 0.1510 0.0070 0.5000 0.1273 0.0100 0.0306 0.0154 0.0200 0.1000 0.4000 0.4828 31   0.1278 0.0500 0.0040 0.0500 0.1834 0.0961 0.0120 0.0061 0.0100 0.0010 0.0500 0.1831 32   0.0010 0.0010  0.0500     0.0050 0.0020 0.0500  33    0.0700  0.0500   0.0001  0.0020 0.0020 0.0200 0.1155 34               35    0.0200   0.0223 0.0120 0.0080 0.0040 0.0010 0.0020   36   0.0082 0.0500 0.2332  0.0389 0.0200 0.0543 0.0274    0.1924 37   0.0603 0.0250   0.0080 0.0450 0.0001 0.0001   0.0050  38   0.0010 0.1000 0.0120    0.0038 0.0041  0.0020 0.0050 0.0044 39               40 0.0010 0.0018 0.2208    0.0112 0.0641 0.0875 0.0939 0.0100  0.0600  41   0.0001    0.0010  0.0001      42 0.0210  0.0143 0.1750 0.0350  0.0224 0.1281 0.0784 0.0842 0.0200 0.0100 0.1200 0.0060 43 0.0060 0.1023 0.0031    0.0032 0.0190 0.3189 0.3422 0.1000 0.0100 0.0200  44 0.6600 0.1318 0.0573 0.0250   0.0034 0.0190 0.0873 0.0937 0.2000 0.0100 0.0150  45 0.0110 0.0563 0.0010      0.0271 0.0291 0.0500  0.0050  46 0.2910 0.6368 0.0307 0.0250  0.3000 0.0109 0.0621 0.1865 0.2002 0.4720 0.0100 0.0200  47 0.0010  0.0020 0.1750 0.5385 0.0500 0.0424 0.2432 0.0744 0.0799 0.0500 0.8010 0.0200 0.0125 48   0.0010  0.1612  0.0027 0.0160 0.0073 0.0078 0.0500 0.0500   49               50                Ecosystem Models of Newfoundland, Past and Present, Page 70  1900-1905 diet continued?  30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 1                    2                    3                    4                    5                    6                    7                    8                    9                    10     0.000   0.001            11                    12                    13                    14                    15                    16                    17                    18                    19                    20     0.002               21                    22                    23     0.012   0.001            24                    25     0.012   0.001            26     0.011   0.001            27                    28     0.001               29     0.001               30 0.005  0.011  0.075  0.010 0.011            31 0.005    0.086   0.292            32   0.002     0.007            33     0.115   0.135            34                    35     0.115               36     0.115  0.050 0.067            37     0.057               38     0.057  0.040 0.067            39                    40          0.001  0.010        41                    42     0.012     0.020 0.050 0.020        43          0.303 0.050 0.300        44     0.003     0.303 0.100 0.300 0.015       45          0.120 0.250 0.120        46    0.100 0.019     0.120 0.150 0.120 0.015       47 0.439 0.35 0.658 0.513 0.295 0.75 0.450 0.418 0.500 0.020 0.200 0.020 0.120     0.05  48 0.551 0.65 0.329 0.387 0.013 0.25 0.450  0.500 0.010 0.150 0.010 0.240     0.48  49             0.085     0.37 1.0 50          0.103 0.050 0.100 0.525 1.0 1.0 1.0 1.0 0.10   Page 71, Back to the Future on Canada?s East Coast   APPENDIX D:    BALANCED MODEL AND DIET MATRIX 1450  Input parameters of the balanced 1450 model (values in bold are estimated by ECOPATH). Group name Trophic level Biomass P/B Q/B EE P/Q Walrus 3.310 0.246 0.060 16.846 0.001 0.004 Cetaceans 4.070 0.533 0.050 9.000 0.150 0.006 Grey seals 4.380 0.078 0.060 15.000 0.890 0.004 Harp Seals 4.130 1.313 0.102 17.412 0.032 0.006 Hooded Seals 4.360 0.263 0.109 13.100 0.145 0.008 Ducks 3.000 0.008 0.250 54.750 0.001 0.005 Piscivorous Birds 4.310 0.448 0.250 54.750 0.028 0.005 Planktivorous Birds 3.530 0.097 0.250 54.750 0.001 0.005 Adult Cod > 40cm 3.940 8.162 0.104 1.091 0.441 0.095 Juv Cod ? 40 cm 3.630 1.452 0.155 1.637 0.657 0.095 American plaice >35cm 3.450 6.207 0.083 1.698 0.950 0.049 American plaice ?35cm 3.360 14.501 0.124 2.547 0.950 0.049 Greenland halibut >65cm 4.310 0.929 0.026 1.193 0.649 0.022 Greenland halibut ? 65 cm 4.220 0.283 0.040 1.789 0.911 0.022 Yellowtail Flounders 3.120 6.729 0.317 3.271 0.950 0.097 Witch flounder 3.020 8.277 0.235 2.304 0.950 0.102 Winter flounder 3.080 4.771 0.267 1.644 0.950 0.163 Skates 4.230 0.441 0.233 1.779 0.950 0.131 Dogfish 4.000 0.054 0.159 2.210 0.950 0.072 Redfish 3.680 13.864 0.113 1.702 0.950 0.066 Transient Mackerel ( >29cm) 3.850 0.107 0.530 5.940 0.950 0.089 Large demersal piscivores (> 40 cm) 4.280 1.134 0.098 1.107 0.950 0.088 Large demersal piscivores (? 40cm) 3.890 20.017 0.147 1.660 0.950 0.088 Large Demersal Feeders (> 30cm) 3.360 3.335 0.155 1.386 0.950 0.112 Small demersal feeders 3.260 23.046 0.232 2.079 0.950 0.112 Other small demersals 3.090 15.148 0.564 4.474 0.950 0.126 Lumpfish 3.590 4.796 0.114 1.374 0.950 0.083 Greenland cod 3.910 5.618 0.101 1.265 0.950 0.080 Salmon 4.260 0.448 0.279 4.093 0.950 0.068 Capelin 3.260 18.812 0.578 4.900 0.887 0.118 Sandlance 3.200 41.176 0.981 4.904 0.950 0.200 Arctic cod 3.370 31.853 0.573 3.601 0.950 0.159 Herring 3.290 13.951 0.510 4.131 0.950 0.124 Transient Pelagics 4.030 0.645 0.183 1.999 0.950 0.091 Small Pelagics 3.420 3.787 0.638 5.291 0.950 0.121 Small Mesopelagics 3.380 11.051 1.422 4.789 0.950 0.297 Shortfin squid 3.960 5.571 0.600 4.000 0.950 0.150 Arctic Squid 3.280 13.766 0.500 3.333 0.950 0.150 Large Crabs (>95 cm) 2.920 0.174 0.380 4.420 0.680 0.086 Small Crabs  (? 95 cm) 3.080 25.839 0.380 4.420 0.950 0.086 Lobster 2.930 10.297 0.380 4.420 0.950 0.086 Shrimp 2.460 18.796 1.450 9.670 0.950 0.150 Echinoderms 2.000 103.215 0.600 6.670 0.950 0.090 Polychaetes 2.000 40.733 2.000 6.330 0.950 0.316 Bivalves 2.000 82.387 0.570 22.220 0.950 0.026 Other benthic invertebrates 2.000 44.746 2.500 12.500 0.950 0.200 Large zooplankton 2.560 148.956 3.433 13.732 0.950 0.250 Small zooplankton 2.000 168.784 8.400 28.000 0.950 0.300 Phytoplankton 1.000 118.114 93.100 - 0.500 - Detritus 1.000 725.759 - - 0.461 -  Ecosystem Models of Newfoundland, Past and Present, Page 72  Balanced diet in 1450:  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1                2                3 0.001               4 0.001               5 0.001               6                7    0.0000            8                9   0.1090 0.0060 0.024           10  0.00000 0.0110 0.0010 0.001  0  0.001 0.01 0  0.001 0.009  11    0.0210            12 0.01  0.0080 0.0010     0.043 0 0.001 0.001 0.001   13    0.0010 0.001           14   0.0010 0.0000 0    0 0 0  0 0  15 0.004  0.0080 0.0500 0.035    0.002  0 0.012    16 0.004  0.0330 0.0500 0.131    0  0  0.003   17 0.004  0.0330 0.0440 0.035           18   0.0040 0.0000     0    0.001   19  0.00200              20   0.0070 0.0060 0.012    0.021 0  0.001 0.129   21   0.0050    0.002         22  0.02200              23 0.002 0.02200 0.0450 0.0000   0.005  0 0      24  0.02200  0.0130 0.022           25 0.01 0.02200 0.0280 0.0120 0.066  0.005  0.062 0.008 0.006 0.009 0.087 0  26 0.016  0.0030 0.0260   0.018  0.036 0.029 0.007 0.023 0.02 0.007  27  0.00900 0.0160    0.018  0.001       28 0.002 0.00300 0.0040 0.0020   0.018  0.001       29  0.01000 0.0020    0.002         30 0.044 0.01000 0.0130 0.0530 0.01  0  0.053 0.113 0.053 0.001 0.48 0.838 0.039 31  0.07600 0.4910 0.2890   0.281  0.261 0.048 0.228 0.142  0 0.04 32  0.21700 0.0020 0.2210 0.123  0.337  0.054 0.05 0.001 0.006 0.033 0.05  33  0.07900 0.0820 0.0200 0.119  0.054  0.012 0.025      34   0.0050  0.014  0.002      0.001   35  0.08000 0.0470 0.0000 0.049  0.03         36  0.04400 0.0110 0.0010   0.084  0.004 0.001   0.011 0.009  37   0.0330 0.0150 0.084  0.03  0.003    0.001   38  0.07900  0.0010 0.084  0.054  0.006 0.003 0.001 0 0.016 0.031  39   0.0010 0.0010     0.001       40 0.12   0.0000     0.063 0.037 0.066 0.039    41 0.001        0.061       42 0.12   0.1370   0.034  0.092 0.123 0.004 0.02 0.017 0.022  43 0.05        0.011 0 0.401 0.175  0 0.073 44 0.1        0.015 0.027 0.022 0.173   0.404 45 0.3   0.0000  0.9   0.049 0.007 0.081 0.034   0.03 46 0.2   0.0000  0.1   0.03 0.217 0.101 0.219 0.002 0.004 0.37 47  0.19200  0.0300    0.957 0.116 0.301 0.028 0.145 0.004 0.029 0.043 48 0.01 0.12100      0.043  0  0    49                50                  Page 73, Back to the Future on Canada?s East Coast   1450 diet continued?  16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1                 2                 3                 4                 5                 6                 7                 8                 9                 10   0.034 0.02 0  0.01 0 0.002 0    0.002   11                 12   0.001    0.071 0.032 0.001 0.001       13                 14   0.001 0.003   0 0      0.001   15       0.012 0.006         16   0.005    0.004 0.002         17                 18       0.004 0.002 0 0       19                 20   0.136 0.053 0.007  0.024 0.013 0.019 0.001       21                 22                 23   0.042 0.013   0.136 0.067 0 0       24                 25   0.112 0.035 0.001  0.154 0.076 0 0 0.002  0.016    26 0.009 0.071 0.028 0.01   0.107 0.057 0.001 0.001 0.008  0.317  0.009 0.071 27                 28                 29   0.01              30   0.125 0.151 0.007 0.5 0.127 0 0.031 0.015 0.005 0.1 0.05 0.483   31   0.125 0.05 0.004 0.05 0.184 0.097 0.012 0.006 0.01 0.001 0.079 0.183   32   0.001 0.001  0.05     0.005 0.002 0.079    33    0.07  0.05   0  0.002 0.002 0.032 0.116   34                 35    0.02   0.022 0.012 0.008 0.004 0.001 0.002     36   0.008 0.05 0.233  0.039 0.021 0.054 0.027    0.192   37   0.059 0.025   0.008 0.046 0 0   0.008    38   0.001 0.1 0.012    0.004 0.004  0.002 0.008 0.004   39                 40 0.001 0.002 0.216    0.011 0.036 0.088 0.05 0.01  0.095  0.001 0.002 41   0.001    0.001 0.03 0.001 0.045       42 0.021  0.014 0.175 0.035  0.022 0.129 0.078 0.084 0.02 0.01 0.19 0.006 0.021  43 0.006 0.102 0.003    0.003 0.019 0.319 0.343 0.102 0.01 0.032  0.006 0.102 44 0.66 0.132 0.056 0.025   0.003 0.019 0.087 0.094 0.203 0.01 0.024  0.66 0.132 45 0.011 0.056 0.001      0.027 0.029 0.051  0.008  0.011 0.056 46 0.291 0.637 0.03 0.025  0.3 0.011 0.063 0.187 0.2 0.479 0.01 0.032  0.291 0.637 47 0.001  0.002 0.175 0.539 0.05 0.042 0.246 0.074 0.08 0.051 0.801 0.032 0.013 0.001  48   0.001  0.161  0.003 0.016 0.007 0.008 0.051 0.05     49                 50                  Ecosystem Models of Newfoundland, Past and Present, Page 74  1450 diet continued?  32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 1                  2                  3                  4                  5                  6                  7                  8                  9                  10     0   0          11                  12                  13                  14                  15                  16                  17                  18                  19                  20     0.002             21                  22                  23     0.012   0.001          24                  25     0.012   0.001          26     0.011   0.001          27                  28     0.001             29     0.01             30 0.005  0.001  0.075  0.001 0.011          31 0.005    0.086   0.293          32   0.002     0.007          33     0.115   0.135          34                  35     0.115             36     0.115  0.05 0.067          37                  38     0.057  0.04 0.067          39     0.01             40          0.001  0.01      41                  42     0.012     0.02 0.05 0.02      43          0.303 0.05 0.3      44     0.003     0.303 0.1 0.3 0.015     45          0.12 0.25 0.12      46    0.1 0.019     0.12 0.15 0.12 0.015     47 0.439 0.35 0.665 0.513 0.295 0.75 0.454 0.418 0.5 0.02 0.2 0.02 0.12     48 0.551 0.65 0.332 0.387 0.013 0.25 0.454  0.5 0.01 0.15 0.01 0.24     49             0.085     50          0.103 0.05 0.1 0.525 1 1 1 1  

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