Document View

Home , Bill Ricker, Ray Beverton, Walther Herwig

Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=1&s...

Databases selected: Multiple databases...

Salmon farms destroying wild salmon populations in Canada, Europe: study ALISON AULD . Canadian Press NewsWire . Toronto: Feb 11, 2008.

Abstract (Summary) The authors, including the late Halifax biologist Ransom Myers, claim the study is the first of its kind to take an international view of stock sizes in countries that have significant salmon aquaculture industries. The paper didn't look to the causes of the declines, which have been discussed in a series of studies over the last decade that have linked disease, interbreeding of escaped salmon and lice from farmed fish with reductions.

Full Text (618 words)

HALIFAX _ Salmon farming operations have reduced wild salmon populations by up to 70 per cent in several areas around the world and are threatening the future of the endangered stocks, according a new scientific study.

The research by two Canadian marine biologists showed dramatic declines in the abundance of wild salmon populations whose migration takes them past salmon farms in Canada, Ireland and Scotland.

``Our estimates are that they reduced the survival of wild populations by more than half,'' Jennifer Ford, lead author of the study published Monday in the Public Library of Science journal, said in Halifax.

``Less than half of the juvenile salmon from those populations that would have survived to come back and reproduce actually come back because they're killed by some mechanism that has to do with salmon farming.''

The authors, including the late Halifax biologist Ransom Myers, claim the study is the first of its kind to take an international view of stock sizes in countries that have significant salmon aquaculture industries.

Ford said wild salmon populations in Atlantic Canada have been hit the hardest, with rivers in New Brunswick and Newfoundland that have stocks that swim past farms dropping steeply over the years. The scientists compared the survival of wild salmon that travel near farms to those that don't, finding that upward of 50 per cent of the salmonid that do pass by farms don't survive.

``There's really strong evidence that this can have impacts on wild salmon and in particular in places like Atlantic Canada, where Atlantic salmon populations are doing so badly,'' Ford said.

``It's worrying.''

The paper didn't look to the causes of the declines, which have been discussed in a series of studies over the last decade that have linked disease, interbreeding of escaped salmon and lice from farmed fish with reductions.

An article last December asserted that Canadian fish farming is destroying wild salmon stocks and could completely wipe them out within four years in one area of British Columbia. The study published in the journal Science contends that aquaculture damages wild populations by infecting juveniles with fatal parasites.

Trevor Swerdfager, director general of aquaculture management for the federal Fisheries Department, said he will take a close look at the new research. But he added he has so far not seen any proof that salmon farms harm wild populations.

``We look at the impact of salmon farming on wild salmon _ if there is one _ and we just haven't seen those sort of impacts,'' he said from Ottawa.

He said stock declines, particularly in the Bay of Fundy, are still a bit of a mystery, but there are other pressures at play that

1 of 2 8/2/2008 4:15 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=1&s...

could be linked to the reductions.

Ecosystem changes, fishing and other stresses linked to climate change are likely having an effect on the health of the wild populations.

``Atlantic salmon populations are not what they were historically, but can you tie that to the absence or presence of salmon farms? I don't think so,'' he said, adding that researchers looking at that stock have never linked the decline to farms.

The latest research by Ford, which covered a period from 2003 to 2006, also looked at a large region off British Columbia, which has a substantial salmon aquaculture industry.

Ford said only pink salmon that passed by salmon farms in that region showed sharp declines.

She said some salmon populations in the Bay of Fundy are endangered, while one has become extinct. She and Myers, who died last year after the research was complete, found that the return of juvenile salmon to the bay to spawn are less than 10 fish a year, whereas there were hundreds of them in the 1980s.

Indexing (document details) Subjects: Aquaculture, Salmon, Fish, Studies, Farming Locations: Canada Author(s): ALISON AULD Document types: News Publication title: Canadian Press NewsWire. Toronto: Feb 11, 2008. Source type: Periodical ProQuest document ID: 1427637581 Text Word Count 618 Document URL: http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?did=1427637581&sid=2&Fmt=3&c lientId=12520&RQT=309&VName=PQD

2 of 2 8/2/2008 4:15 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=0&s...

Databases selected: Multiple databases...

Biologist exposed pillaging of ocean; [ONT Edition] Toronto Star . Toronto, Ont.: Apr 5, 2007. pg. A.24

Abstract (Summary) Ransom Myers, who died in Halifax last week, was never popular with the federal Department of Fisheries and Oceans. He was formally reprimanded for suggesting that the main cause of the cod collapse was Canadian overfishing, and he eventually left the department to do fisheries research with Dalhousie University.

Myers did extensive work on a variety of fish species, documenting the collapse of stocks of large pelagic species and, most recently, the precipitous decline - by almost 90 per cent - of shark populations.

Myers died at 54, with the potential for many years of fisheries science ahead of him. With fellow scientist Boris Worm, Myers was very much the canary in the coal mine when it came to impending fisheries disasters.

Full Text (432 words)

Ransom Myers, who died in Halifax last week, was never popular with the federal Department of Fisheries and Oceans. He was formally reprimanded for suggesting that the main cause of the cod collapse was Canadian overfishing, and he eventually left the department to do fisheries research with Dalhousie University.

But it is his message about cod that people in this province should pay the closest attention to.

He was one of the early birds warning about a collapse, and about the effects of unlimited industrial fishing, and his stark comments were anything but welcome in the politico/scientific world of fisheries and quotas during the 1990s.

"The collapse was all blamed on the environment, on the seals, on the foreigners, when it was primarily Canadians. ... I saw that as the big lie, blaming it on anything but ourselves," he said later.

In Julius Caesar, Shakespeare wrote "The evil that men do lives after them. The good is oft interred with their bones."

That's every bit as true in fisheries science.

Not only will we not be able to benefit from the concerns that could be raised by his future work, there's also a real danger that this country's fisheries apologists will take every possible opportunity to bury Myers' research and opinions with him.

No one likes to admit that they are actually the cause of a problem; it's much more comfortable to point a finger somewhere else.

Because of that, the big lie that it's all foreigners and seals who are to blame for problems in the fishery is still very much in vogue in this province, and will probably continue to be.

Ransom Myers developed a bank of scientific knowledge on the East Coast fishery that can hardly be equalled.

But that doesn't mean anyone will keep that knowledge alive, especially when it gets in the way of our own preconceived notions.

In the end, we'll probably all be comfortable to stick with a convenient fiction, rather than facing the inconvenient truth.

1 of 2 7/27/2008 7:59 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=0&s...

And we'll continue to bleat righteously, "It's everyone else's fault!"

This is an edited version of an editorial yesterday in the St. John's Telegram.

[Illustration] Ransom Myers

Indexing (document details) Companies: Dalhousie University ( NAICS: 611310 ) Section: Editorial Publication title: Toronto Star. Toronto, Ont.: Apr 5, 2007. pg. A.24 Source type: Newspaper ISSN: 03190781 ProQuest document ID: 1250147581 Text Word Count 432 Document URL: http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?did=1250147581&sid=6&Fmt=3&c lientId=12520&RQT=309&VName=PQD

2 of 2 7/27/2008 7:59 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=6&s...

Databases selected: Multiple databases...

Large fish are disappearing from oceans, study warns ; Stocks at 10 per cent of 1950 levels 'Catch has to be reduced substantially'; [Ontario Edition] Peter Calamai . Toronto Star . Toronto, Ont.: May 15, 2003. pg. A.22

Abstract (Summary) Drawing on untapped records, Canadian researchers found that vast ocean-going fleets using satellites and underwater scanners can reduce stocks of individual fish species by 90 per cent in no more than 15 years. Then the fleets move on to another species.

Serious depletion of commercial fish species began in the 1950s with the introduction of Japanese longlines that laid thousands of hooks across a 100-kilometre span. Ocean-going factory ships with trawling nets accelerated the pace and invaded even the Antarctic waters, said [Ransom Myers].

Previously untapped historical fishing information let the two researchers produce the most apocalyptic in a recent spate of warnings about the dramatic decline of fish stocks worldwide. Particularly valuable were meticulous catch records kept by the Japanese for their longline fishing fleet.

Full Text (650 words)

The world's oceans are running on empty, warns a pioneering scientific study published today, with mechanized fleets cutting the population of all large fish to only 10 per cent of 1950 levels.

Drawing on untapped records, Canadian researchers found that vast ocean-going fleets using satellites and underwater scanners can reduce stocks of individual fish species by 90 per cent in no more than 15 years. Then the fleets move on to another species.

"We're incredibly efficient at killing fish. There is no frontier left," said lead researcher Ransom Myers, a world-recognized fisheries biologist and professor at Dalhousie University in Halifax.

This research, coming on top of other localized studies, is certain to increase pressure on governments to impose tough conservation measures.

The European Union is already proposing to cut catch quotas by half in the North and Irish seas.

In Canada, the federal government closed the Newfoundland cod fishery. Yesterday, four Liberal MPs from the province pleaded with the Prime Minister for more help for the devastated fishery.

Myers, a former federal fisheries scientist, said Canada's handling of Atlantic cod is simply one example of the "incompetence and greed" obvious in industrial fishing around the world.

"We forgot very quickly how much fish there was out there in the ocean. There were more than a million tonnes of haddock in the southern Grand Banks in the 1950s. After a decade of fishing it was gone," he said.

The study concludes a similar dismal decline has befallen nearly every kind of commercially harvested fish, from deep oceans species like blue marlin and tuna to offshore groundfish like cod and flounder.

The Canadian research, featured on the cover of the influential research journal Nature published today, takes the groundbreaking approach of surveying entire fish communities- the different commercial species that live in the same waters

1 of 2 7/27/2008 8:12 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=6&s...

and are generally caught together, like cod and haddock.

"Their approach sends a clear message that many people don't want to hear- there just aren't many fish left out there," said Jeremy Jackson, a fishery expert from the Scripps Institute of Oceanography in California.

Earlier research by Jackson recorded the collapse of coastal fisheries worldwide. The new Dalhousie research covers fish 30 centimetres in length and longer caught on four continental shelves and in nine ocean systems.

Continental shelves and open ocean account for three-quarters of the world's annual fish catch, according to the U.N. Food and Agricultural Organization.

The World Wildlife Fund (WWF) urged governments to use the study findings as justification to reduce fleets and ban fishing in critical ocean tracts where spawning and rearing occur.

"We know there are tremendous political pressures to catch the very last fish. But this study shows that we're only managing the dregs of what was once there," said Bob Rangeley, a marine biologist in charge of the WWF Atlantic Canada office.

Study co-author Boris Worm said much tougher catch quotas would have to be set based on detailed studies of individual species.

"The catch has to be reduced substantially. Half might not be enough in some cases," said Worm, a post-doctoral researcher soon to become a biology professor at Dalhousie.

Those records showed severe drops across vast regions of ocean. Where the Japanese longlines in the late 1950s regularly caught more than 10 fish for every 100 hooks over a 13-hour period, they were catching less than one fish by 1980.

Credit: Toronto Star

Indexing (document details) Author(s): Peter Calamai Dateline: OTTAWA Section: NEWS Publication title: Toronto Star. Toronto, Ont.: May 15, 2003. pg. A.22 Source type: Newspaper ISSN: 03190781 ProQuest document ID: 647853511 Text Word Count 650 Document URL: http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?did=647853511&sid=7&Fmt=3&cl ientId=12520&RQT=309&VName=PQD

2 of 2 7/27/2008 8:12 PM vii

TRIBUTE

Ransom Aldrich Myers (1952–2007): In memoriam

Jeffrey A. Hutchings

Ransom Aldrich Myers (Ram) was a mathematically Fig. 1. Ransom Aldrich Myers (Ram) photographed near Halifax, gifted, intellectually pugnacious, and passionately humane Nova Scotia (February 2004). scientist committed to the unconstrained communication of science to decision makers and to society (Fig. 1). He died 27 March 2007 in Halifax, Nova Scotia, Canada, 4 months after being diagnosed with inoperable brain cancer. He was 54 years old and in the prime of his scientific career.

Beginnings The son of a cotton plantation owner in the southern United States, Ram (Randy to his parents and siblings) was born on Friday, the 13th of June, 1952, in the rural community of Lula, Mississippi. After graduating with a B.A. in Physics from Rice University in Houston in 1974, Ram spent 2 years working for Schlumberger Overseas S.A. in the oil fields of Kuwait. He then spent his 23rd year travel- ling throughout Africa before embarking across the Atlantic to the Caribbean on an 8.5 m sailboat. In 1977, rather than disappointing his father (whose ancestors included Confed- erate soldiers) by attending a university in the northern “Yankee” states, Ram left the United States for Canada, a country he first visited as a 13-year-old when his cousin took him there on a canoe trip to Ontario’s Algonquin Park. Having enrolled in postgraduate studies at Dalhousie Uni- versity under the supervision of Roger Doyle, Ram defended his M.Sc. in Mathematics on 6 October 1980 before defending his doctorate in Biology 3 years later (20 August 1983). One would have been hard pressed to predict most of Ram’s future research endeavours based on his postgraduate thesis topics. In his M.Sc. thesis (dedicated simply “To my mother”; she had died 2 years before his thesis defence), he presented a model for the evolution of dispersal, based on a nonlinear, stochastic system of difference equations. His primary conclusion was that “the ESS [Evolutionarily Stable mortality trade-offs could be used to estimate natural mortal- Strategy] dispersal distribution is independent of dominance, ity rates, and the adaptive basis for empirical patterns of model assumptions of haploidy or diploidy, maternal or indi- covariation between growth rate and size at maturity. vidual genotypic control of dispersal, and the timing of mat- Prior to defending his doctoral thesis, Ram accepted a po- ing” (Myers 1981). The overall objective of his doctoral sition as research scientist in the Department of Fisheries thesis (Myers 1983) was to use optimization and inverse op- and Oceans (DFO) in St. John’s, Newfoundland, where he timization theory to study the evolution of life histories, fo- undertook work on Atlantic salmon, Salmo salar.Atthe cussing in particular on the evolutionary stability of time, I was an M.Sc. student, nearing the end of one of two postmaturation growth, the degree to which reproduction– 6-month field seasons. I had collected reams of life history

Received 21 November 2007. Accepted 27 November 2007. Published on the NRC Research Press Web site at cjfas.nrc.ca on 20 December 2007. J20278E J.A. Hutchings. Department of Biology, Dalhousie University, Halifax, NS B3H 4J1, Canada (e-mail: [email protected]).

Can. J. Fish. Aquat. Sci. 65: vii–xii (2008) doi:10.1139/F07-906 © 2007 NRC Canada viii Can. J. Fish. Aquat. Sci. Vol. 65, 2008 data on two migratory variants of Atlantic salmon in Terra Fig. 2. Number of research contributions (including anonymously Nova National Park, northeastern Newfoundland, when John peer-reviewed book chapters and papers in the primary scientific Gibson, a DFO scientist of British descent, remarked, “Jeff, literature, but excluding letters, consultant reports, and government we’ve just hired a new scientist — Ransom Myers — and research documents and working papers) authored or co-authored he’s very interested in salmon. I told him about your work. by Ram Myers from 1982 to 2007. Solid line represents the total You really ought to meet this chap.” It was the first and only number of contributions; the broken line represents those pub- time I heard Ram referred to as a “chap” — many other lished in the Canadian Journal of Fisheries and Aquatic Sciences. things mind you, but chap was never amongst them. Al- The labelled horizontal bars identify the range in publication year though we met briefly at a DFO seminar shortly thereafter in for six research themes. October 1983, it was not until April 1984, when I was a fi- nancially challenged postgraduate and Ram was a finan- cially flush government scientist, that he hired me as a research associate. I am not sure whether Ram was prepared for Newfound- land, but I think it is fair to say that Newfoundland was not entirely prepared for Ram. At 31 years, he possessed a massive head of dark-brown hair and a long, flowing beard. When standing on a rock, overlooking the ocean, in a New- foundland “breeze”, the beard did lend Ram a certain physi- cal presence not unlike that of Thor, the Norwegian god of thunder. It was a prescient characterization fitting for a man who would slay many a sacred cow with his question-laden, data-infused hammer. However, looking god-like in a William Blake or Michel- angelo sort-of-way was one thing, but it did not come with any divinely bestowed power of flight. We had to drive to work. Every morning, I would pick Ram up at his home, and we would navigate the 5 km or so to DFO on the White Hills in St. John’s. I learnt very quickly that Ram was a Roff), John Thorpe, threshold traits, the quantitative genetics creature of habit. While I parked at the curb, he would of liability, Sewall Wright, and Ronald Fisher. scramble down the steps with a backpack full of books and One of my most cherished “Ram-isms” was his response papers in one hand and a steaming mug of coffee in the to my scepticism of the utility of, and logical basis for, dis- other. Riding shotgun, sans lid, only a portion of this coffee tinguishing between r- and K-selection (a scepticism I firmly ever made it down Ram’s throat. As Ram might have put it, embrace today). Ram’s simple response, written in his own the probability of the coffee finding its way to the floor, seat, uniquely expressive hand, was “r-K-ic”. Among the myriad or dash of the car was nontrivial. On other occasions, reck- interactions we were to share over the coming years, none, oning that a half mug of coffee would not quite do it, Ram but for these four letters, captured quite so well the succinct- decided that a full breakfast was in order. With his backpack ness, wit, clarity, and mischievousness that Ram was always over a shoulder, he would gingerly make his way to the car, capable of. nursing the ubiquitous coffee in one hand and balancing a bowl of cereal, milk, and spoon in the other. Then we would Research contributions and collaborations drive off, Ram simultaneously gesticulating, eating, and talking, while I minded the coffee. Ram’s breadth of interest in the arts (he read all manner of Unsurprisingly, given the topics of his postgraduate thesis nonfiction voraciously, loved live theatre, and thoroughly en- research, Ram was adamant that fundamentally important joyed opera) was mirrored by the diversity of the science he questions in biology could not be addressed without a sound undertook. At the time of writing (December 2007), Ram knowledge of ecology, evolutionary biology, and quantitative had co-authored 153 research contributions (including anon- genetics. He argued this point repeatedly (among others) ymously peer-reviewed book chapters and papers in the pri- during Ecology and Evolution Discussion Group meetings mary scientific literature, but excluding letters, consultant held weekly in the Biology Department at Memorial Univer- reports, and government research documents and working sity of Newfoundland. The verbal jousting that took place papers). His primary research outlet was the Canadian Jour- between Ram and people such as Doug Morris and Jake nal of Fisheries and Aquatic Sciences, the journal in which Rice, neither of whom could be described as shrinking vio- almost half (46%) of his 98 papers through to 2002 were lets, were legendary both for the degree of uninhibited en- published (47 of 141 papers overall) (Fig. 2). Among these thusiasm they exuded and for the unparalleled influence was his first scientific paper, which explored ways of esti- their interactions had on some of us during our formative mating natural mortality and associated trade-offs from fish postgraduate years. It was Ram who, all before 1987, intro- life history data (Myers and Doyle 1983) and his first sole- duced me to life history evolution, additive genetic variance, authored paper, which documented a survival cost of repro- epistasis, John Maynard Smith, ESSs, maximum likelihood, duction in mature male Atlantic salmon parr (Myers 1984). APL (A Programming Language, a computer program for He also co-authored nine publications in Science and three which the sole username at DFO was “droff”, after Derek in Nature (including a Reply).

Fig. 3. Proportional representation of research contributions by Fig. 4. Photograph of Ram standing next to the Department of Ram Myers for each of six research themes: life history evolu- Fisheries and Oceans’ experimental stream channel at Noel Paul’s tion (hatched area), oceanography (dark grey), recruitment vari- Brook, a tributary of Exploits River, Newfoundland, where he and ability (stippled area), conservation biology (open), population I undertook experimental work on Atlantic salmon (October 1984). modelling (solid), and general biology (light grey).

Ram worked very closely with others, successfully combining his modelling and mathematical skills with the varied strengths of his collaborators, a group that included fisheries scientists, statisticians, stock assessment modellers, conservation biologists, oceanographers, field biologists, evolutionary ecologists, natural historians, and legal scholars. Numerically, the most prominent of his collaborators were Nick Barrowman (n = 18 publications), Jeff Hutchings (n = 16), Gordon Mertz (n = 16), Mike James (n = 10), and Boris Worm (n = 9). Among others who co-authored five or more papers with Ram were Noel Cadigan, Ken Drinkwater, Jamie Gibson, contributions (Fig. 3). Predicated by his doctoral thesis re- Mike Hammill, Ian Jonsen, Dan Kehler, Andy Rosenberg, search (Myers 1983), Ram’s keen interest in how fitness and Gary Stenson. Additional collaborators, each of whom trade-offs influence life history evolution led to a series of co-authored three of Ram’s dual-authored contributions, in- papers published in the mid-1980s on alternative reproduc- cluded Bill Montevecchi, Pierre Pepin, Jeff Runge, and Peter tive tactics in male Atlantic salmon (Fig. 4). Among his nine Ward. Even if not identified explicitly, the contributions of co-authored papers that have been cited more than 100 times these individuals and many others are interwoven within the (hereafter, his highly cited papers), the earliest was a prod- fabric of the corpus of Ram’s research. uct of this life history research and represented one of the first attempts to use genetic markers to estimate fertilization Research career success in fishes (Hutchings and Myers 1988). In 1989, Ram became part of a small group of modellers Newfoundland and statisticians at DFO that comprised the Resource As- Upon arrival at DFO, Ram learned of data on salmon parr sessment and Survey Methodology Centre of Disciplinary collected between 1956 and 1963 in Little Codroy River, Expertise (RASM CODE), under the direction of John Newfoundland. Quickly grasping the uniqueness of this data Hoenig. This section was intended to serve as a national re- set, he immediately set about estimating the heightened mor- source for other DFO research scientists. One consequence tality experienced by mature male parr relative to immature of this shift in Ram’s responsibilities was a substantive in- males and the loss of anadromous salmon productivity that crease in the proportional representation of papers (1988– would ensue (Myers 1984). These analyses comprised part 1992) on various elements of population modelling (particu- of his work on life history evolution, one of six research larly the demography of marine mammals), a research theme themes in which I have attempted to categorize his research that was to remain dominant throughout the remainder of his

© 2007 NRC Canada x Can. J. Fish. Aquat. Sci. Vol. 65, 2008 career. It was also during this period that Ram’s interest in 2000s can be attributed to a considerable degree to the oceanography was most prominent. His work on environ- attention generated by Casey and Myers’ (1998) highly cited mental correlates of larval and juvenile mortality, for exam- paper in Science. ple, contributed to his first two publications on recruitment Following intellectually in the footsteps of fisheries scien- variability (Myers 1991; Pepin and Myers 1991), a topic he tists Bill Ricker and Ray Beverton and pioneer life history was to explore in increasingly greater detail through the modeller Lamont Cole, it was Ram’s primary assertion that 1990s. the maximum rate of population growth was the single most The period 1993–1997 was Ram’s most wide ranging in important parameter required to fully understand the factors terms of research (Fig. 3). It was also the period during that affect the ability of fish populations to sustain exploita- which his interest in recruitment was at its height, as Ram tion, to resist decline in the face of unpredictable environ- examined how density, life history, and oceanography af- mental change, and to recover following collapse. It was this fected the magnitude and spatial scale of recruitment vari- parameter (rmax) that represented the intellectual and empiri- ability. Four of his highly cited papers were published cal anchor that grounded much of Ram’s research, be it the during this period: one examined the influence of density on life histories of zooplankton, alternative reproductive behav- juvenile mortality in marine fishes (Myers and Cadigan iours in Atlantic salmon, the relationship between parental 1993); one represented the first meta-analysis to test for and offspring abundance in harvested populations, or the depensation, or Allee effects, in fish stock–recruitment rela- factors that affect the collapse, recovery, and extinction risk tionships (Myers et al. 1995); and two pertained to the col- of marine fishes. lapse of marine fishes, particularly Atlantic cod, Gadus Two influential examples of Ram’s research on maximum morhua (Hutchings and Myers 1994; Myers et al. 1997a). population growth were published between 1997 and 1999. It seems reasonable to conclude that the diligence and fer- Myers et al. (1997b) introduced methods to estimate rmax vour with which Ram undertook his later work in conserva- from stock–recruit data, applying it here to multiple stocks tion biology had its genesis during the time between 1993 of Atlantic cod and making explicit the link that exists be- and 1997 when we (Ram, Nick Barrowman, and myself) un- tween rmax and recovery. Based on an analysis of more than dertook our work on the collapse of northern cod. The loss 700 spawner–recruit relationships, Myers et al. (1999; one of of this once massive fishery had, and continues to have, the nine highly cited papers) concluded that maximum an- enormous economic, sociological, and emotional impacts on nual reproductive rate is relatively constant across a broad Newfoundlanders. You could not work at DFO in New- range of fish species. Ram declared this result to be a “very foundland in the early 1990s (as we three did) and not be important finding” (Myers et al. 1999). A touch of arro- cognizant of the obligations that scientists have to society of gance, to be sure, but on this occasion, as on many others, communicating their research widely, publicly, and honestly. he was right. This perspective was not, however, shared by all. The so- Following the stock–recruitment database that Nick Bar- cietal and moral obligation of scientists to communicate the rowman, Jessica Bridson, and he had compiled in the mid- results of their research was being traded off by the desire of 1990s and armed with an extraordinarily acute understanding some bureaucrats to control the information that flowed from of analytical modelling techniques, Ram continued his mar- DFO to the public. Bureaucratic impediments to the commu- shalling of massive data sets from around the globe. During nication of fisheries science were discussed by Hutchings et a 5-year period beginning in 2003, Ram’s research contribu- al. (1997), who reported that a DFO scientist had received an tions to conservation biology reached a pinnacle. Concomi- official reprimand for communicating to the media conclu- tant with a highly cited paper in Science on the decline of sions consistent with the peer-reviewed scientific literature pelagic sharks in the Northwest Atlantic (Baum et al. 2003), but inconsistent with the views expostulated by department a publication that was a part of Julia Baum’s M.Sc. research, spokespersons. Ram was the scientist in question (according Ram and postdoctoral researcher Boris Worm took on the to a memorandum; footnote 1, Hutchings et al. 1997). task of estimating the magnitude of the post-1950s decline experienced by large, predatory fishes targeted by industrial- Dalhousie University ized fishing, species such as tunas and billfishes. The au- It was this reprimand that sealed Ram’s future with DFO. thors’ conclusion that the global ocean has lost more than From his perspective, he could “put up and shut up”, or he 90% of large, predatory fishes attracted an unprecedented could leave. He opted for the latter, attaining the right of amount of attention for a publication in marine conservation freedom of expression that universities offer when he biology. The paper by Myers and Worm (2003), published in returned to Halifax in 1997 as Dalhousie’s inaugural Killam Nature, is the most referenced of Ram’s research contribu- Chair in Ocean Studies. Upon arrival at Dalhousie, Ram and tions at present and, having been cited more than 330 times postgraduate Jill Casey completed their work on the extraor- to date, will almost certainly remain so. dinary decline experienced by the barndoor skate, Dipturus It is prudent to note, however, that this recent work has laevis, one of Canada’s larger marine fishes (maximum not been without criticism (e.g., Walters 2003; Hampton et length of 153 cm), that occurred, as Ram frequently put it, al. 2005; Polacheck 2006). In this vein, Ram has been de- “when no one was looking”. Indeed, no one was looking, scribed as one of those responsible for a rift that currently primarily because the focus was traditionally on temporal exists between some fisheries scientists who perceive marine trends in species directly targeted by the fishing industry. fish population declines to have been unduly exaggerated Consequently, changes in the abundance of those species and others who consider it important that studies of marine caught incidentally often went unnoticed. The increased at- biodiversity be integrated with studies of fisheries science tention to bycatch species by fisheries agencies in the early (Pauly 2007). This is a characterization with which Ram

Fig. 5. Photograph of George Lilly (left), Ram (centre), and me in my office at the Department of Fisheries and Oceans, White Hills, St. John’s, Newfoundland, on the occasion of our Wilfred Templeman Publication Award (December 1993).

would have agreed, finding solace in Winston Churchill’s ber of the World Conservation Union (IUCN) Shark Special- assertion, “You have enemies? Good. That means you’ve ist Group, editor for Ecology Letters, and member of science stood up for something, sometime in your life.” The last de- advisory boards for Sierra Club of Canada and Oceana cade has demonstrated the utility of integrating studies of (Washington, D.C.). fields typically associated with conservation biology (e.g., ecology, biodiversity, evolution, genetics) with studies typi- L’envoi cally associated with fisheries science (e.g., temporal changes in fishing mortality, recruitment variability, stock When Ram died, the first thing I thought about were those structure). Pauly (2007) coined this field “fisheries conserva- breakfasts in my car. I never did say anything to him about tion biology”, identifying Ram as one of its founders. the mugs, bowls, and spoons that would be left under the The paper by Myers and Worm (2003) succeeded in bring- passenger seat, often for several days. The fact that he saw ing an extraordinary amount of attention to the plight of the nothing untoward in using my car as a café was, in an odd world’s oceans and to declines in marine fish biodiversity. sort of way, touching. His behaviour in general was not what Among other things, it provided Ram with opportunities to I was used to, but I was drawn to him nonetheless. communicate directly with decision-makers and politicians; When he did not feel threatened, Ram’s demeanour often he served as a witness at hearings of the Canadian House of reflected a child-like sincerity, honesty, and innocence. But it Commons Standing Committee on Fisheries and Oceans is the innocence of children that makes them vulnerable, and (2003, 2005) and at two US Senate Committee hearings on it was this underlying vulnerability, often juxtaposed with un- overfishing (2003). In October 2005, Fortune magazine compromising forthrightness, often juxtaposed with unselfish named Ram one of the “Ten to Watch” (i.e., individuals acts of kindness, that made Ram such a singular individual. whose work Fortune believes will have lasting influence), The collapse of Atlantic cod and myriad other marine citing his work on the decline of large predatory fishes. Rec- fishes has occurred on our collective watch in an alarmingly ognition of Ram’s research excellence over the years came in short period of time. The responsibilities we have to those a variety of other forms. Among his awards were the 1993 who follow us are non-negotiable. It was acceptance of these Wilfred Templeman Award (shared with George Lilly and societal responsibilities that lay behind the passion and enthu- myself; Fig. 5), a 1996 Visiting Fellowship to Imperial Col- siasm that fuelled Ram’s work and the determination with lege at Silwood Park (UK), the inaugural Killam Chair in which he communicated the results of his research to society. Ocean Studies at Dalhousie University (1997), Memorial Uni- There are those who disagreed with Ram, but there are versity of Newfoundland’s Great Auk Lectureship (1999), and few who would disavow the impact he has had on fisheries the Blue Ocean Society for Marine Conservation Science science and marine conservation biology. He earned the re- Award (2004). He also served as Director of the Sloan Foun- spect of lawmakers in Canada and the United States. He is dation’s Future of Marine Animal Populations project, mem- lauded for his mentoring of students and for his ability to

© 2007 NRC Canada xii Can. J. Fish. Aquat. Sci. Vol. 65, 2008 communicate the plight of the world’s oceans broadly and Myers, R.A. 1983. The use of inverse optimization in evolutionary meaningfully. Society has benefited from his scientifically biology. Ph.D. thesis, Dalhousie University, Halifax, N.S. driven provocations and his proddings. They have forced us Myers, R.A. 1984. Demographic consequences of precocious mat- to look very carefully at our oceans, to learn from past mis- uration of Atlantic salmon (Salmo salar). Can. J. Fish. Aquat. takes, and to acknowledge that maintaining the health and Sci. 41: 1349–1353. biodiversity of marine ecosystems is a priority and a funda- Myers, R.A. 1991. Recruitment variability and range of three fish mental responsibility to future generations. We can neither species. NAFO Sci. Counc. Stud. 16: 21–24. afford nor have the right to ignore these matters. Myers, R.A., and Cadigan, N.G. 1993. Density-dependent juvenile Ram Myers was my colleague, my confidante, and my mortality in marine demersal fish. Can. J. Fish. Aquat. Sci. 50: friend, and he is sorely missed. He is survived by his wife, 1576–1590. Rita Kindl Myers, and children, Emily, Rosemary, Sophia, Myers, R.A., and Doyle, R.W. 1983. Predicting natural mortality Carlo, and Gioia. He also leaves his brother, Abbott Myers, rates and reproduction — mortality trade-offs from fish life his- and sisters, Joan Peters and Susan Myers. tory data. Can. J. Fish. Aquat. Sci. 40: 612–620. Myers, R.A., and Worm, B. 2003. Rapid worldwide depletion of predatory fish communities. Nature (London), 423: 280–283. References Myers, R.A., Barrowman, N.J., Hutchings, J.A., and Rosenberg, Baum, J.K., Myers, R.A., Kehler, D.G., Worm, B., Harley, S.J., and A.A. 1995. Population dynamics of exploited fish stocks at low Doherty, P.A. 2003. Collapse and conservation of shark popula- population levels. Science (Washington, D.C.), 269: 1106–1108. tions in the Northwest Atlantic. Science (Washington, D.C.), Myers, R.A., Hutchings, J.A., and Barrowman, N.J. 1997a.Why 299: 389–392. do fish stocks collapse? The example of cod in eastern Canada. Casey, J.M., and Myers, R.A. 1998. Near extinction of a large, widely Ecol. Appl. 7: 91–106. distributed fish. Science (Washington, D.C.), 281: 690–692. Myers, R.A., Mertz, G., and Fowlow, S.P. 1997b. Maximum popu- Hampton, J., Sibert, J.R., Kleiber, P., Maunder, M.N., and Harley, lation growth rates and recovery times for Atlantic cod (Gadus S.J. 2005. Fisheries: decline of Pacific tuna populations exag- morhua). Fish. Bull. 95: 762–772. gerated? Nature (London), 434: E1–E2. Myers, R.A., Bowen, K.G., and Barrowman, N.J. 1999. Maximum Hutchings, J.A., and Myers, R.A. 1988. Mating success of alterna- reproductive rate of fish at low population sizes. Can. J. Fish. tive maturation phenotypes in male Atlantic salmon, Salmo Aquat. Sci. 56: 2404–2419. salar. Oecologia, 75: 169–174. Pauly, D. 2007. Obituary: Ransom Aldrich Myers (1952–2007). Hutchings, J.A., and Myers, R.A. 1994. What can be learned from Nature (London), 447: 160. the collapse of a renewable resource? Atlantic cod, Gadus Pepin, P., and Myers, R.A. 1991. Significance of egg and larval morhua, of Newfoundland and Labrador. Can. J. Fish. Aquat. size to recruitment variability of temperate marine fish. Can. J. Sci. 51: 2126–2146. Fish. Aquat. Sci. 48: 1820–1828. Hutchings, J.A., Walters, C., and Haedrich, R.L. 1997. Is scientific Polacheck, T. 2006. Tuna longline catch rates in the Indian Ocean: inquiry incompatible with government information control? did industrial fishing result in a 90% rapid decline in the abun- Can. J. Fish. Aquat. Sci. 54: 1198–1210. dance of large predatory species? Marine Policy, 30: 470–482. Myers, R.A. 1981. The evolution of dispersal in a stochastic envi- Walters, C.J. 2003. Folly and fantasy in the analysis of spatial ronment. M.Sc. thesis, Dalhousie University, Halifax, N.S. catch rate data. Can. J. Fish. Aquat. Sci. 60: 1433–1436.

Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=22&...

Databases selected: Multiple databases...

Few of world's large fish remain, study says Alanna Mitchell . The Globe and Mail . Toronto, Ont.: May 15, 2003. pg. A.2

Abstract (Summary) Some species are perilously close to the point of no return, the study found. The ocean's large sharks will die out unless the fishery catch in the planet's open ocean falls by 50 to 60 per cent, Dr. [Myers] said. And many other species are also right on the brink. The phenomenon is driven by advances in technology such as the sonar methods developed during the Second World War and the satellite methods of finding the ocean's warm fronts where fish once congregated.

Full Text (669 words)

Every single species of large wild fish has been caught so systematically over the past 50 years that 90 per cent of each type have disappeared, according to the first scientific study to assess the fish left in the global ocean.

And, from the tropics to the poles, those left in the sea are only one half to one fifth the size they were before industrialized fishing began in about 1950, says the study which appears as the cover story of today's issue of the scientific journal Nature.

The study by marine biologists Ransom Myers of Dalhousie University in Halifax and Boris Worm of the Institute for Marine Science in Kiel, Germany, catalogues biological destruction that is unprecedented in its global scope and rapidity since the dinosaurs died out 65 million years ago. And it blasts the idea that the oceans have vast pools of uncaught fish waiting to be discovered.

"We have to quit thinking about the ocean as a blue frontier," said Dr. Myers, who is Killam Chair of Ocean Studies at Dalhousie. "What we have is a remnant."

Dr. Worm, who is the Emmy-Noether Fellow in Marine Ecology at the German institute, was more blunt. The entire global ocean, which makes up 70 per cent of the Earth's surface, is no longer in even close to its natural state.

"It is now a man-made system," Dr. Worm said, adding that it may be less stable and is probably less predictable as a stabilizing force of the planet.

"We are tampering with the life-support system of the planet and that's not a good thing to do."

A separate scientific study published yesterday by the Species Survival Commission of the Swiss-based World Conservation Union warned that other ocean creatures are faring no better than the big fish. Some of the smaller air-breathing cetaceans, the group that includes dolphins and porpoises, are also in critical danger, often because they are caught inadvertently along with fish by industrial fisheries. The Yangtze dolphin, for example, has been reduced to a couple of dozen individuals left in the world.

The Nature study on fish took 10 years and examined all major fisheries in the world in nine oceanic systems and on four continental shelves. The data from the open ocean came from Japanese fleets of long-line fisheries, in which hooks are set at regular intervals across vast kilometres of ocean at the same time. The study included the fish most prized as human foodstuff: tuna, marlin, swordfish, cod and halibut.

These fish, as well as sharks, are at the top of the ocean's food chain, and their loss will have a profound effect -- if an unpredictable one -- on the whole ecosystem of the global ocean, Dr. Myers said.

Some species are perilously close to the point of no return, the study found. The ocean's large sharks will die out unless the fishery catch in the planet's open ocean falls by 50 to 60 per cent, Dr. Myers said. And many other species are also right on the brink. The phenomenon is driven by advances in technology such as the sonar methods developed during the Second World War and the satellite methods of finding the ocean's warm fronts where fish once congregated.

1 of 2 7/27/2008 9:07 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=22&...

Other scientific studies show that the ocean's populations of big fish are now so depleted that people today spend far more time and energy to catch fewer fish than even a few years ago.

"One population by one population, we are pushing species to extinction," Dr. Myers said.

The fate of the Atlantic cod, with its population cut down to 1 per cent of the pre-1950 numbers, is unknown, one of the scariest signals of how unpredictable biological destruction on this level can be, Dr. Myers said. And the Pacific sardines are showing no signs of recovery either, he said.

But other species may recover if strong measures to cut levels of fishing are taken immediately, Dr. Worm said.

* Roy MacGregor is

on assignment.

Credit: EARTH SCIENCES REPORTER

Indexing (document details) Author(s): Alanna Mitchell Section: Science Publication title: The Globe and Mail. Toronto, Ont.: May 15, 2003. pg. A.2 Source type: Newspaper ISSN: 03190714 ProQuest document ID: 1059653791 Text Word Count 669 Document URL: http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?did=1059653791&sid=23&Fmt=3& clientId=12520&RQT=309&VName=PQD

2 of 2 7/27/2008 9:07 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=24&...

Databases selected: Multiple databases...

Northern cod officially declared endangered Alanna Mitchell . The Globe and Mail . Toronto, Ont.: May 3, 2003. pg. A.13

Abstract (Summary) COSEWIC is the scientific committee charged by the federal government with figuring out how healthy the populations of Canada's wildlife are. The designation "endangered" means "a species facing imminent extirpation or extinction," and is the category just ahead of outright disappearance.

Full Text (449 words)

1 of 3 7/27/2008 9:08 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=24&...

The mighty northern cod, historic key to Canada's settlement and prosperity, fished until last week, has been officially designated as being on the brink of extinction.

Yesterday, the northern cod was listed for the first time as "endangered" by the Committee on the Status of Endangered Wildlife in Canada after its meetings in Whitehorse.

COSEWIC is the scientific committee charged by the federal government with figuring out how healthy the populations of Canada's wildlife are. The designation "endangered" means "a species facing imminent extirpation or extinction," and is the category just ahead of outright disappearance.

The committee said the designation is merited because the population of northern cod has collapsed catastrophically, falling more than 99 per cent over 40 years.

"To lose a species that is so enormously resilient requires an enormous political effort," said Ransom Myers, a marine ecologist at Dalhousie University in Halifax.

He noted that historical records show that the cod drew settlers to Newfoundland and other parts of Canada's eastern lands. "We're losing what is arguably the species most important to the history of the country," Dr. Myers said.

He said the final irony to this huge international ecological collapse is that the Canadian government decided only last week -- days before the COSEWIC designation -- to close the cod fishery and did not say how long it would remain closed.

"The lunacy of only closing the cod fishery last week is just incredible," said Dr. Myers. "There are only a few little cod left."

Canada's three other populations of cod -- the Laurentian, Arctic and Maritime -- also made the list of species at risk.

When European ships arrived on Canada's shores in the 1600s, fishermen could lower buckets over the side and catch all the cod they wanted.

In the 1980s, quotas of northern cod were set at 220,000 to 230,000 tonnes. By 1992, the fishery had collapsed and the federal government closed it, predicting a full recovery within two years. It didn't happen.

But the government reopened the fishery again in 1999, allowing a catch of 9,000 tonnes. In 2000, the quota was 7,000 tonnes. The year after, 5,600 tonnes. Last year, the quota was again set for 5,600 tonnes, but cod fishermen couldn't find enough to fill the quota.

Jeffrey Hutchings, a marine biologist at Dalhousie and a member of the COSEWIC decision-making body, said it's now clear the reopening in 1999 was catastrophic to the few cod that remained.

"This might well be the greatest biological catastrophe in Canadian history," Dr. Hutchings said.

Dr. Myers said that the greater tragedy is that populations of Atlantic salmon, halibut, haddock and walrus have also been seriously damaged from being fished too determinedly.

Indexing (document details) Author(s): Alanna Mitchell Section: National News Publication title: The Globe and Mail. Toronto, Ont.: May 3, 2003. pg. A.13 Source type: Newspaper ISSN: 03190714 ProQuest document ID: 1059972911 Text Word Count 449 Document URL: http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?did=1059972911&sid=23&Fmt=3& clientId=12520&RQT=309&VName=PQD

2 of 3 7/27/2008 9:08 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=21&...

Databases selected: Multiple databases...

THE OCEANS IN CRISIS Alanna Mitchell . The Globe and Mail . Toronto, Ont.: May 17, 2003. pg. F.7

Abstract (Summary) "We're changing things in unprecedented ways," Prof. [Ransom Myers] said. "The cod was there for more than five centuries and now it's gone."

Full Text (1500 words)

Newfoundland isn't the half of it. This week's scientific bombshell reveals that all the world's oceans are emptying of fish, ALANNA MITCHELL writes. But the cod fishery is the worst-case scenario -- and to deny that, experts say, is sheer idiocy

At first, even the scientists conducting the study didn't believe their results.

First one population of big fish, then another, cut down by 90 per cent just since industrialized fishing started five decades ago.

First blue marlin, then sailfish and finally swordfish in the tropical Atlantic Ocean. First codfish, then flatfish on the southern Grand Banks.

As one species was fished out, another would rise temporarily, spurred by the extra food available in the sea. Then it, too, would be targeted and heavily fished (or killed by accident when commercial fish were caught), and driven to dramatic population declines.

And not one open ocean system, but nine of them. Not one continental shelf, but four. And not just some species, but all of the biggest fish in the ocean, throughout the global ocean, in every single major fishery in the world from the tropics to the poles.

"If you look at the big picture, you see this amazingly consistent pattern," said Boris Worm, the Emmy-Noether Fellow in Marine Ecology at the Institute for Marine Science in Kiel, Germany.

He and Ransom Myers, who holds the Killam Chair in Ocean Studies at Dalhousie University in Halifax, are the authors of the first comprehensive, long-term look at how many fish are left in the ocean since modern commercial fishing fleets began to scour the sea with the help of sonar and satellite. Published in this week's issue of the prestigious scientific journal Nature, it has staggered the public imagination.

Species after species, the researchers found the same pattern: Thriving populations speedily crashed as the voracious commercial fishing fleets moved in. And crashed to the tune of 80 per cent within the first 15 years of sustained fishing.

In the Gulf of Thailand, for example, 60 per cent of large fin fish, sharks and skates were killed off during the first five years of industrialized fishing.

The fish that are left are far smaller on average than they were before. Some get as big as half the size of fish 50 years ago. Some get to only a fifth.

It would have been easier for Profs. Myers and Worm not to believe any of it, to concentrate instead on the crashes of local fisheries, rather than on the whole global story. But after sifting through the masses of data collected over a full decade, they realized that denial was not an option.

They realized that what they dubbed this "grim mosaic" could get far, far worse. Unless they drew attention to the problem, and unless the world was persuaded to halt the destruction, humanity could well face a future without fish.

Not just fish on the dinner table, but fish in the seas. Unless all the fish at the very top of the ocean food chain get a chance to

1 of 3 7/27/2008 9:06 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=21&...

get on with their lives -- eating and breeding -- some of the species could go extinct. Maybe, eventually, all of them.

They wrote their paper. Nature's editorial team was so gobsmacked that the story made the cover, the scientific equivalent of making a sermon to the masses on the highest of high holidays.

But denial is still going strong. Profs. Worm and Myers knew that their findings would cause a storm. And when they passed their paper around to many of the leading fisheries scientists and managers in the world, the scientific denial held fast. While many of the scientists could accept the general finding that fish populations across the global ocean are hugely depleted, they questioned whether some of the individual species are in such dire straits.

The reason the study is a landmark, and a controversial one, is that it uses data that go back 50 years, to when the ocean's fish were abundant. Most fisheries scientists don't go back that far, so they have been comparing current levels of fish to levels that had already been heavily fished out -- which makes the current populations of some fish, such as bluefin tuna, seem closer to normal.

To Prof. Myers, the denial is just as quintessentially human an activity as the urge to fish in the first place. "We have a hard time imagining that our local actions, summed over the world, could have such huge effects," he said.

Worse, Prof. Worm said, is that having 10 per cent of fish left in the sea can still provide profit for fishery workers -- until they are fished out, and the cost of catching them rises above the prices they can fetch on the luxury market.

That's why it's so hard to convince local fishermen that they must stop fishing, or cut their catch. The economics require taking the long view instead of just worrying about money today.

But of all the denial, of all the destruction, what is happening today in Newfoundland is in a class of its own.

"Cod is one of the very bad examples," Prof. Worm said. "It's not one of the typical examples."

To Prof. Myers, who has worked on the data on cod for decades, the cry to keep fishing in Newfoundland is sheer idiocy.

None of the rest of the global biological destruction that he and Prof. Worm catalogued is as thorough as that off the Grand Banks of Newfoundland, Prof. Myers said. Instead of being reduced to 10 per cent of historic populations, like so many other big fish of the sea, cod stocks have fallen to just 1 per cent. At those levels, it may not be possible for cod to come back. At those levels, any cod being caught are just babies.

The cod stocks have fallen so low that they have gone past the point at which scientists are able to predict what they will do.

"We're changing things in unprecedented ways," Prof. Myers said. "The cod was there for more than five centuries and now it's gone."

Strangely enough, even though the Nature paper has focused so much public attention on fishing, the fate of the fleets is only a small part of what Profs. Myers and Worm are worried about. The greatest worry -- and therefore the cause for greater public denial -- reaches far beyond the fellows running the boats.

Because it's not just fish. Recent examinations of the seas have found that dolphins and porpoises are in trouble too. Some species may not live out this decade.

Shark populations are in terrible shape, partly the result of being caught in the kilometres-long lines set for commercial fish, but also because of the growing practice of shark-finning: Sharks are pulled out of the water just long enough for the fishermen to slice off fins and tails for the shark-cartilage remedies popular in Asia.

The live sharks, now finless, are then dropped back into the water, where, unable to navigate, they fall to the ocean floor and drown. Some shark populations have dropped so low that marine biologists fear the sea animals are on the brink of extinction.

Green sea turtles are in danger too. Pacific leatherback turtles are balanced on the knife's edge between survival and extinction.

Put together, these pieces tell a far scarier story for humanity than one about a community losing its livelihood, a family driven out of work or even a province robbed of its natural patrimony. These pieces tell the tale of ecological meltdown within the global ocean. The ocean makes up 70 per cent of the surface of Earth. The ocean regulates climate, temperature, humidity, oxygen and carbon systems -- the very ability of the planet to sustain life.

What happens when that massive planetary regulator is altered this dramatically and this rapidly? Is this playing with fire?

"This is playing with nuclear explosives here," Prof. Myers said. "We're losing the ocean."

2 of 3 7/27/2008 9:06 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=21&...

The irony is that to restore the fish and therefore the ocean to health, all that needs to be done is nothing. No seeds have to be sown, no harvests reaped, no forced feeding or extra nurturing or gentle care. The solution is simply to leave the fish alone and let them reproduce.

This week, while Prof. Worm was fielding calls from all over the world about his study, he kept looking out the window of his office in Kiel to the vast expanse of the Baltic Sea. Fifty years ago, it was full of big tuna and whales, he said. Today, the biggest creatures in its waters are jellyfish, zooplankton and the odd herring. It is, in effect, a sea without fish.

He noted wryly that some fishermen in fishless seas have turned to catching the jellyfish for world tabletops. The jellyfish are still okay. But maybe not for long.

Globe senior features writer Alanna Mitchell's book about the world's biological health will be published in January.

Indexing (document details) Author(s): Alanna Mitchell Section: Focus Publication title: The Globe and Mail. Toronto, Ont.: May 17, 2003. pg. F.7 Source type: Newspaper ISSN: 03190714 ProQuest document ID: 1059591261 Text Word Count 1500 Document URL: http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?did=1059591261&sid=23&Fmt=3& clientId=12520&RQT=309&VName=PQD

3 of 3 7/27/2008 9:06 PM NEWS & VIEWS NATURE |Vol 447 |10 May 2007

OBITUARY Ransom Aldrich Myers (1952–2007) Chronicler of declining fish populations.

Ransom Myers’s life as a working industry pressure, had failed to protect scientist spanned the period during this vital resource and the province which classical fisheries science that depended on it. He was a leader lost its way. Founded a century among the handful of DFO scientists ago as an applied discipline, it was who published evidence that excessive essentially devoted to assisting fishing was the sole cause of the stock’s

the fishing industry in locating collapse. UNIV. ABRIEL/DALHOUSIE D. and monitoring fish stocks and Unsurprisingly, given the press and optimizing catches. The concept of public reaction to these papers, Myers ‘sustainability’ was tacked on only was reprimanded by his superiors. much later, as successive fish stocks He took refuge in academia, taking collapsed. Today, fisheries scientists in 1997 the Killam Chair in Ocean are a divided lot, torn between those Studies at Dalhousie. From there, loyal to the interests of the fishing aided by colleagues and several industry and those who see their brilliant graduate students, he role as studying marine biodiversity, published a series of papers showing and so protecting it from the largest that politically motivated, slothful remaining hunt on the planet. optimism had masked the systematic Myers was a leader among those destruction of marine resources, who caused this rift. In passing away and marine biodiversity in general so soon, he will not see it heal, as it — not just in Canada and its marine inevitably must. jurisdictions, but the world over. He began his career in 1984 These papers, again based on innocuously enough. Armed with a judicious analysis of existing time- freshly minted PhD from Dalhousie series data, documented the worldwide University in Halifax, Canada, he depletion, through industrial fishing, took work — like most of the world’s fisheries from hundreds of reports of fisheries agencies of skate, sharks, large bottom fishes and, scientists — in a government laboratory, throughout the world. finally, large pelagic fishes such as marlin in this case one belonging to Canada’s Myers succeeded in renormalizing the and tuna. Each new paper baited the staff Department of Fisheries and Oceans (DFO) data in the spawning-stock and recruitment of yet another agency into angry rebuttals. in St John’s, Newfoundland. As was usual, series so that they could be expressed in Myers had the thick skin required for such he was involved in assessing the local, comparable units within each stock and acrimonious debates. Once, when asked commercially important fish stocks. Equally between stocks and species. In this way, he about the controversy that one of his papers typically, as a sideline he joined the search for was able to show that, at low population sizes, had generated, his response was simply: an answer to the greatest mystery of fisheries the females of most commercial marine fishes “They are wrong, and I am right!” science: what is it that determines the number produce only three to five viable young a year, In the process, Myers helped to found of young fish that enter an adult population, in spite of the millions of eggs they may shed fisheries conservation biology. This given a parental stock that releases immense and that are fertilized in the process. Until discipline is devoted to identifying exploited quantities of tiny eggs into the vagaries of a then, most fisheries scientists had believed fish populations and species threatened turbulent ocean? that overexploited populations could easily with extinction, and suggesting measures Myers’s attack on this ‘stock recruitment’ rebound from depletion induced by fishing for rebuilding them, along with the problem was atypical in that he eschewed the — a belief now known as the millions-of-eggs ecosystems in which they are embedded. correlational studies that had been favoured fallacy. With this result, published in 1999, Correspondingly, its primary clients are up to that time. Such studies link recruitment Myers disposed of one of the central reasons not the owners of trawlers, longliners, variability to some environmental parameter, why fisheries scientists had underestimated purse seiners and other industrial vessels, and invariably fail the year after they are the impact of fishing and provided fisheries but national and international agencies published. Rather, his attack on the problem managers with over-optimistic advice. mandated with maintaining marine used the formidable mathematical skills he Meanwhile, the stock of northern cod off biodiversity and ecosystems, and the many had acquired through his earlier degrees: Canada’s Atlantic province of Newfoundland benefits they provide for society as a whole. a BSc in physics from Rice University in and Labrador, managed under the auspices If fisheries conservation biology and its Houston, Texas, and an MSc in mathematics of the DFO, had collapsed. A moratorium guiding philosophy thrive, it will be because from Dalhousie. on its commercial exploitation was imposed of the energies of the likes of RAM — as Rather than relying on data from a single in 1992. It had been one of the most Myers, who died of brain cancer on 27 March species — the bane of much work in the important fish stocks in the North Atlantic, this year, liked to be called. RAM is survived area — Myers constructed a meta-analysis commercially and culturally important to by his wife Rita and five children. of more than 500 time-series of spawning- Canada, and was supposedly one of the best Daniel Pauly stock sizes and subsequent recruitment in studied and managed fish stocks in the world. Daniel Pauly is at the Fisheries Centre, a vast number of commercially exploited Myers did not go along with the voracious University of British Columbia, species. Together with a few colleagues, he seals, cold temperatures and other excuses 2202 Main Mall, Vancouver V6T 1Z4, Canada. had painstakingly collected these time-series invented by an agency that, by caving in to e-mail: [email protected]

160

!"#$ &$()*$+,$$$ -! ./#/!0$$$#1!-1# $ Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=0&s...

Databases selected: Multiple databases...

Science and Technology: Ocean's eleventh hour?; Overfishing The Economist . London: May 17, 2003. Vol. 367, Iss. 8324; pg. 93

Abstract (Summary) That the seas are being overfished has been known for years. What Ransom Myers and Boris Worm of Dalhousie University in Halifax, Nova Scotia, have shown is just how fast things are changing. They have looked at half a century of data from fisheries around the world. Their methods do not attempt to estimate the actual biomass (the amount of living biological matter) of fish species in particular parts of the ocean, but rather changes in that biomass over time. According to their paper in the latest issue of Nature, the biomass of large predators (generally the most valuable species) in a new fishery is reduced on average by 80% within 15 years of the start of exploitation.

Full Text (693 words)

Fish stocks are dropping rapidly. Predators are falling fastest

WHEN prehistoric man arrived in new parts of the world, something strange happened to the large animals. Mammoths, mastodons, massive ground sloths, woolly rhinoceros, cave bears and large flightless birds suddenly became extinct. Smaller species survived. The large, slow-growing animals were easy game, and were quickly hunted to extinction. Now something similar could be happening in the oceans.

That the seas are being overfished has been known for years. What Ransom Myers and Boris Worm of Dalhousie University in Halifax, Nova Scotia, have shown is just how fast things are changing. They have looked at half a century of data from fisheries around the world. Their methods do not attempt to estimate the actual biomass (the amount of living biological matter) of fish species in particular parts of the ocean, but rather changes in that biomass over time. According to their paper in the latest issue of Nature, the biomass of large predators (generally the most valuable species) in a new fishery is reduced on average by 80% within 15 years of the start of exploitation. In some long-fished areas, it has halved again since then.

The researchers' data came from two sources. Those for fisheries on the continental shelves were derived from standardised research surveys of large bottom-dwelling fish such as cod, flatfish, skates and rays. Those for fish in the open ocean, such as tuna, billfish and swordfish, were estimated from figures collected by Japan's longline fishing fleet (composed of vessels that trail fishing lines with baited hooks at intervals along their lengths). In this case, changes in biomass were estimated by comparing the number of fish caught for every 100 hooks now and in the past.

Dr Worm acknowledges that the figures are "only a first order approximation" but says that if anything they are conservative. One reason for this is that fishing technology has improved, so the comparison is not genuinely like-for-like. Today's vessels can find their prey using satellites and sonar, which were not available 50 years ago. That means a higher proportion of what is in the sea is being caught, so the real difference between present and past is likely to be worse than the one recorded by changes in catch sizes. In the early days, too, longlines would have been more saturated with fish. Some individuals would therefore not have been caught, since no baited hooks would have been available to trap them, leading to an underestimate of fish stocks in the past. Furthermore, in the early days of longline fishing, a lot of fish were lost to sharks after they had been hooked. That is no longer a problem, because there are fewer sharks around now.

This sort of result does not, of course, convince everyone. The Inter-American Tropical Tuna Commission, an inter- governmental body that manages tuna fisheries in the eastern Pacific, has a different view of the status of tuna stocks. Robin Allen, its director, says longlines only catch older tuna, and the data the authors are using therefore comprise only part of the actual stock. Other studies are necessary, he says, to work out the relationship between reductions in catch rates and actual removals from stock.

1 of 2 8/2/2008 4:03 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=0&s...

Dr Myers and Dr Worm, however, stand by their conclusions. They argue that their work gives a correct baseline, which future management efforts must take into account. They believe the data support an idea current among marine biologists, that of the "shifting baseline". The notion is that people have failed to detect the massive changes which have happened in the ocean because they have been looking back only a relatively short time into the past. As Jeremy Jackson of the Scripps Institution of Oceanography, in La Jolla, California, puts it: "We had oceans full of heroic fish. Hemingway's 'Old Man and the Sea' was for real." That matters because theory suggests that the maximum sustainable yield that can be cropped from a fishery comes when the biomass of a target species is about 50% of its original levels. Most fisheries are well below that, which is a bad way to do business.

[Illustration] Caption: The way we were

Indexing (document details) Subjects: Commercial fishing, Endangered & extinct species, Ecosystems, Environmental impact, International Classification Codes 9180, 8400, 1530, 5400 Document types: News Section: Science and Technology Publication title: The Economist. London: May 17, 2003. Vol. 367, Iss. 8324; pg. 93 Source type: Periodical ISSN: 00130613 ProQuest document ID: 337568981 Text Word Count 693 Document URL: http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?did=337568981&sid=1&Fmt=3&cl ientId=12520&RQT=309&VName=PQD

2 of 2 8/2/2008 4:03 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=1&s...

Databases selected: Multiple databases...

Biologist Ransom A. Myers, 54; Warned of Overfishing in Oceans; [FINAL Edition] Patricia Sullivan - Washington Post Staff Writer . The Washington Post . Washington, D.C.: Mar 29, 2007. pg. B.8

Abstract (Summary) He said his conclusions were shocking because people had lost sight of the true magnitude of the declines because they did not look back far enough in history. Trained as a physicist and mathematician, Dr. Myers dived into local and regional fishing reports from all over the world, figured out how to examine and compare the numbers, and calculated what was happening to marine life in all the seas.

Dr. Myers also asserted last year that appetite for shark-fin soup is ridding the world's oceans of one of its most ancient creatures and threatening ecosystems buffeted by overfishing. Some sharks, such as the hammerhead and the great white, have been reduced by upward of 70 percent in the past 15 years, and others, such as the silky white tip, have disappeared from the Caribbean.

"We are in massive denial and continue to bicker over the last shrinking numbers of survivors, employing satellites and sensors to catch the last fish left," Dr. Myers told Science Daily in 2003. "We have to understand how close to extinction some of these populations really are. And we must act now, before they have reached the point of no return. I want there to be hammerhead sharks and bluefin tuna around when my five-year-old son grows up. If present fishing levels persist, these great fish will go the way of the dinosaurs."

Full Text (976 words)

Correction: The March 29 obituary of Ransom Myers said 1.1 million fish are discarded each year; the figure should have been 1.1 million tons of fish. (Published 3/30/2007)

Ransom A. Myers, 54, a world-renowned fisheries biologist whose research showed that the number of large fish in the world's oceans has dropped by 90 percent in the past 50 years, died of a brain tumor March 27 at a hospital in Halifax, Nova Scotia.

Dr. Myers, who analyzed vast amounts of data from government and industry reports around the globe, also said the size of large fish has declined dramatically in recent decades. Tuna used to be twice as big, and marlins were once as large as killer whales, he said.

He warned governments, the fishing industry and consumers that unless commercial fishing is sharply curtailed and management of fisheries is improved, many large marine species will become extinct. That, he said, could lead to economic disruptions, food shortages in seafood-dependent developing nations and lasting damage to marine ecosystems.

He said his conclusions were shocking because people had lost sight of the true magnitude of the declines because they did not look back far enough in history. Trained as a physicist and mathematician, Dr. Myers dived into local and regional fishing reports from all over the world, figured out how to examine and compare the numbers, and calculated what was happening to marine life in all the seas.

"He had the ability to see trends in vast amounts of data, extract those patterns and communicate them so everybody else could understand," said Boris Worm, a colleague at Dalhousie University in Nova Scotia. "His major contribution was really to wake up the world to the ongoing depletion of fish stocks, of marine life, worldwide."

Dr. Myers also asserted last year that appetite for shark-fin soup is ridding the world's oceans of one of its most ancient

1 of 3 8/2/2008 4:58 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=1&s...

creatures and threatening ecosystems buffeted by overfishing. Some sharks, such as the hammerhead and the great white, have been reduced by upward of 70 percent in the past 15 years, and others, such as the silky white tip, have disappeared from the Caribbean.

The unintentional capture of fish not wanted by fishermen results in the death of 1.1 million fish each year, or one in four caught in commercial nets, he reported in 2005.

On March 30, the journal Science will publish a major paper, co- written by Dr. Myers and with details under embargo, about the importance of sharks in marine ecosystems.

"We certainly hope this most recent paper will add a great deal of insight into ecosystem problems in overfishing," said Charles H. Petersen, his co-author and a marine sciences professor at the University of North Carolina at Chapel Hill.

Dr. Myers published more than 100 peer-reviewed papers and more than six book chapters, and he served on numerous international commissions on the population dynamics of marine organisms. Colleagues described him as warm and fun-loving, passionate about ferreting out information and so honest that he refused to couch his findings.

Andrew Rosenberg, former deputy director of the National Marine Fisheries Service at the National Oceanic and Atmospheric Administration, called Dr. Myers "a consummate scientist."

"He'd say, 'I'm going to find all the data' on an issue, and he wasn't kidding. He'd find every data set available on fish population anywhere in the world. Not only was he a brilliant analyst but worked astoundingly hard, too," said Rosenberg, a professor of natural resources policy and management at the University of New Hampshire. "He had the ability to home in on what's the real question. It's not how many sharks are here, but what's the major change here. He figured out an analytical method that addresses the big questions."

A native of Mississippi, Dr. Myers received a scholarship and graduated from Rice University in Houston. From Dalhousie University, he received a master's degree in mathematics in 1981 and a doctorate in biology in 1984. He was the Killman chair in oceans studies there.

Working as a research scientist for the Department of Fisheries and Oceans in St. Johns, Newfoundland, during the 1980s and 1990s, he reported that the collapse of the northern cod population was not caused by hungry or aggressive seals, as government and industry officials said, but by industrial fishing practices and overfishing.

In 2004, he was one of six leading marine scientists who were hired as government advisers only to find their recommendations stripped from a National Marine Fisheries Service report -- that federal action was urgently needed to protect more than a dozen populations of West Coast salmon and steelhead trout from the threat of extinction.

"We were trying to do an honest job and we were called radical environmentalists," Dr. Myers told the Los Angeles Times. "It was troubling to administrators we objected to the policy that habitat did not need to be protected. There was a clear implication if we continued to talk about policy, the group would be disbanded."

Recognized by Fortune magazine as one of its Ten People to Watch in 2005, Dr. Myers influenced a large number of environmental scientists, many of whom visited him in his last weeks in the hospital, Worm said.

Survivors include his wife, Rita Kindl-Myers, and five children, of Halifax.

Credit: Washington Post Staff Writer

Indexing (document details) Subjects: Deaths -- Myers, Ransom A People: Myers, Ransom A Author(s): Patricia Sullivan - Washington Post Staff Writer Document types: Obituary Section: METRO

2 of 3 8/2/2008 4:58 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=1&s...

Publication title: The Washington Post. Washington, D.C.: Mar 29, 2007. pg. B.8 Source type: Newspaper ISSN: 01908286 ProQuest document ID: 1246140141 Text Word Count 976 Document URL: http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?did=1246140141&sid=2&Fmt=3&c lientId=12520&RQT=309&VName=PQD

3 of 3 8/2/2008 4:58 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=0&s...

Databases selected: Multiple databases...

Ten to Watch Anonymous . Fortune . New York: Sep 19, 2005. Vol. 152, Iss. 6; pg. 281, 1 pgs

Abstract (Summary) Presented are ten people whose activities will have lasting influence, including: 1. Gamal Mubarak, 2. Barack Obama, 3. Ransom Myers, 4. Sergey Brin, and 5. Hwang Woo Suk.

Full Text (537 words)

[Headnote] Fame is fleeting. But even if these men and women are not household names in 75 years, what they're doing now will have lasting influence.

Gamal Mubarak

President in waiting. An MBA who worked as an investment banker in London, Mubarak-despite protestations to the contrary-has been groomed to succeed his father, Hosni, as President of Egypt, the intellectual capital of the Arab world. Gamal, 42, is regarded as an economic reformer with a worldly outlook. Some believe he has the capacity to do what his 77-year-old father could not-make Egypt a workable model of tolerance, freedom, and prosperity.

Barack Obama

U.S. Senator (D-lllinois). The most charismatic politician of his generation, the 44-year-old Obama is a crossover politician with strong appeal among both black and white Americans. He will be a key player as the U.S. becomes a more racially diverse society.

Ransom Myers

Oceanographer. Myers's work on the dynamics of fish species provided startling evidence of the 90% population decline since 1950 in bluefin tuna, giant blue marlin, and other big fish. A professor at Canada's Dalhousie University, Myers is working to develop new and better ways to husband the wealth beneath the sea.

Sergey Brin, Larry Page, Jimmy Wales

Web stars. Brin and Page, founders of Google, brought to market the favorite roadmap for the web. In Wikipedia, Wales created a reader-written, interactive encyclopedia. The innovations this trio pioneered have accelerated the democratization of information on the Internet-a phenomenon that is only beginning to show its potential. In a future where information is everywhere all the time, the splashes Google and Wikipedia made will cast ripples in ways that are unpredictable but profound.

Hwang Woo Suk

Stem-cell researcher. A national hero in South Korea, Hwang, with his team at Seoul National University, has won headlines for cloning a cow, a pig, a human embryo, and a dog. The implications are huge. Cloned human embryos could yield therapeutic stem cells to provide breakthrough treatments for conditions as varied as Alzheimer's and spinal-cord trauma. The ethical debate is just beginning. But one thing is certain: Hwang's research will be a major factor in defining the future of medicine.

Angela Belcher

1 of 2 7/27/2008 7:11 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=0&s...

Nanotechnologist. Based at MIT, Belcher specializes in biomimicry-investigating how nature grows things and then trying to replicate the process in the lab. The idea is to ereate forms that produce other things, such as genetically engineered viruses that can grow electronic components much as an abalone grows a shell. Possible applications run the gamut from vaccine storage to superstrong materials to improved computing.

David Laibson

Economist. The emerging discipline of neuro-economics says that economic decisions are the product of interactions between different brain parts that evolved at different times and for different reasons. Armed with this insight, scholars like Harvard's Laibson are beginning to reconstruct economics from the prefrontal cortex up. That might take us to a far better understanding of why consumers buy, why investors buy and sell-and how everything from 401 (k) plans to marketing strategies to tax policies should be put together.

Freddy Adu

Soccer phenom. One final brave prediction: Adu, now 16, leads the U.S. to victory in the World Cup of 2020, providing the breakthrough that makes soccer a major sport in America.

Indexing (document details) Subjects: Future, Predictions, Manypeople Classification Codes 9180 Author(s): Anonymous Document types: Cover Story Section: 75: HOW THE WORLD WILL WORK Publication title: Fortune. New York: Sep 19, 2005. Vol. 152, Iss. 6; pg. 281, 1 pgs Source type: Periodical ISSN: 00158259 ProQuest document ID: 896827611 Text Word Count 537 Document URL: http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?did=896827611&sid=2&Fmt=3&cl ientId=12520&RQT=309&VName=PQD

2 of 2 7/27/2008 7:11 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=4&s...

Databases selected: Multiple databases...

Unconventional biologist makes a splash with shark study; Tracks declining fish species Studies come with marketing blitz; [ONT Edition] Kelly Toughill . Toronto Star . Toronto, Ont.: Jan 22, 2005. pg. F.03

Abstract (Summary) His work has certainly had an effect. The shark paper - Rapid Worldwide Depletion of Predatory Fish Communities - led to a ban on the shark-fin fishery . He is in great demand at conferences and at hearings. He is such a frequent visitor to the corridors of power that he carries an up-to-date pass to the Washington, D.C., subway in his wallet.

Today, [Ransom Myers] spends little time near the ocean. His particular talent lies in the computer, in systematically assembling the data uncovered by others about what lies beneath the waves. He oversees 17 graduate students working in Italy, Australia, Norway and Argentina. Their task, he says, is to count every shark in the sea.

Scott Dunlop for the toronto star Ransom Myers, here looking through a fish tank in his Dalhousie University office, says predator fish species are disappearing. His research has led to a ban on the shark- fin fishery.

Full Text (837 words)

Imagine Ransom Myers playing in the bathtub. There is the squeaky duck, the bar of soap and, of course, the shark.

The shark is key. It is fierce and big and scary. It is universally thrilling, and that, says one of Canada's most eminent biologists, is why he chose sharks to drive home the tragedy of the ocean's global demise.

"If you want to reach the heart through mathematics, you have to look at what 5-year-olds are playing with," says Myers, a Dalhousie University scientist rapidly becoming known as Canada's own international prophet of doom.

"What do we play with? Dinosaurs, whales, sharks; the big predators are what interest humans most."

Myers has certainly reached a lot of hearts. His famous work on sharks is just one of more than 100 scientific papers to chronicle a stunning decline in the plants and animals of the sea.

One paper showed that 90 per cent of large predatory fish like sharks have disappeared from global waters. Another showed stunning declines in the Pacific Ocean populations of leatherback turtles, huge ancient reptiles the size of a small car.

"What is really scary is we don't even know why," Myers says of the turtle phenomenon.

"The terrestrial environment was colonized 100,000 years ago, but in the oceans, there are still undisturbed areas being found, pillaged, destroyed and left, and no one knows what has been lost before it's gone."

In person, Myers seems a caricature of the isolated professor long beard and tiny glasses, socks and open sandals, a cluttered office in a high tower and a tendency to putter.

In reality, Myers is anything but an isolated academic; his powerful computer is changing the way the world thinks. His talent is not just in putting together the mathematical models, it's in getting people to pay attention to them. Every major scientific paper is accompanied by a marketing campaign, often involving a publicist, press releases, video prepared in advance for television news, and a string of experts lined up for interviews.

"If you want to have an effect, your work doesn't end when the paper is published," he says.

His work has certainly had an effect. The shark paper - Rapid Worldwide Depletion of Predatory Fish Communities - led to a ban on the shark-fin fishery . He is in great demand at conferences and at hearings. He is such a frequent visitor to the corridors of power that he carries an up-to-date pass to the Washington, D.C., subway in his wallet.

1 of 2 7/27/2008 8:06 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=4&s...

The value of publicity is something he learned after school, he says, not in it.

Ten years ago, when Myers was with the Department of Fisheries and Oceans, his outspoken views on the collapse of the cod fishery were more than a little unwelcome.

"I was saying that the collapse of the cod stocks was due to overfishing. Back then, no one was supposed to say that. They tried to censure me, and I resigned."

But he didn't stop talking.

It was an odd journey that brought him to this glass-walled office that overlooks his adopted home. Myers grew up on a farm in Mississippi, but knew as a child he wasn't going to stay.

He studied physics at Rice University in Texas, spent a year in Africa, sailed back across the Atlantic Ocean, then landed at Dalhousie University in the '80s for two graduate degrees, a masters in math applied to biology, and then a doctorate in biology.

He didn't set out to study the ocean, he says. He was interested in ecology, and the ocean turned out to be a pleasant place to be. There was the job with the federal government, then a return to university, and teaching.

Today, Myers spends little time near the ocean. His particular talent lies in the computer, in systematically assembling the data uncovered by others about what lies beneath the waves. He oversees 17 graduate students working in Italy, Australia, Norway and Argentina. Their task, he says, is to count every shark in the sea.

He could leave, if he wishes, but he stays, has decided to plant roots in this small city at the edge of a medium-power nation. He can walk home at midday and have lunch with his kids. There is no commute. A little swim club is down the street.

Asked what he would like people to know, what is the most important thing he has learned from the ocean, from living on two continents, from lobbying for change, raising kids, doing interviews, and his answer is immediate

"It is possible to change things," he says. "It isn't possible to change things if you don't think well and work hard, but you can change things. And you don't have to give up family to do it."

[Illustration] Scott Dunlop for the toronto star Ransom Myers, here looking through a fish tank in his Dalhousie University office, says predator fish species are disappearing. His research has led to a ban on the shark- fin fishery.

Credit: Toronto Star

Indexing (document details) Author(s): Kelly Toughill Section: National Report Publication title: Toronto Star. Toronto, Ont.: Jan 22, 2005. pg. F.03 Source type: Newspaper ISSN: 03190781 ProQuest document ID: 782525251 Text Word Count 837 Document URL: http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?did=782525251&sid=7&Fmt=3&cl ientId=12520&RQT=309&VName=PQD

2 of 2 7/27/2008 8:06 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=9&s...

Databases selected: Multiple databases...

We are fishing our oceans to death; [1] Margaret Wente . The Globe and Mail . Toronto, Ont.: Apr 3, 2007. pg. A.15

Abstract (Summary) Prof. [Ransom Myers]'s warnings were not speculation. He based them on a hard slog through the data of ocean trawler records through the years. Back in 2003, he warned, "We've got to cut fishing by 50 per cent, and if it's not done, we're going to lose the pelagic [ocean-going] species." Last week, his final piece of research was published in the journal Science.

Full Text (764 words)

Forget Jaws. The greatest predator on the planet is man, says MARGARET WENTE

Ransom Myers is not a household name. He should be. The Nova Scotia biologist, who died last week at 54, was called the best fish scientist in Canada. He was also a leading authority on the greatest environmental disaster of our time.

It's too bad that global warming gets all the ink, because the danger documented by Prof. Myers is right here, right now. We are fishing out the seas. We don't have to wait for global warming to wipe out species, because we are doing it already. Prof. Myers found that in the past 50 to 100 years, we have fished out more than 90 per cent of the world's biggest predatory fish -- tuna, swordfish, marlin, cod, shark. Most of the ones that remain are much smaller than the ones your grandpa saw. If somebody rewrote The Old Man and the Sea today, the old man's adversary would probably be a minnow.

Today, we don't fish the seas -- we mine them. Ocean-going supertrawlers drag the seas to depths of 600 metres, sucking up the last of the giant bluefin tuna, along with tonnes and tonnes of bycatch (waste fish for which there is no market). They fish out one area and then move on, leaving a virtual desert in their wake.

Prof. Myers's warnings were not speculation. He based them on a hard slog through the data of ocean trawler records through the years. Back in 2003, he warned, "We've got to cut fishing by 50 per cent, and if it's not done, we're going to lose the pelagic [ocean-going] species." Last week, his final piece of research was published in the journal Science. It found that populations of some of the biggest shark species off the eastern coast of the United States had also plunged by 90 per cent or even more. "If you go to any reef around the world, except for those that are really protected, the sharks are gone," he said.

Forget Jaws. The greatest predator on the planet is man. But what's beneath the seas is also beneath the radar screens of many of us. You can bet that if polar bears or pandas were disappearing as fast as the large pelagic fish, far more people would be demanding far more serious conservation efforts.

No one knew this better than Prof. Myers. For years, he worked for the Department of Fisheries and Oceans, where he warned that the cod were being overfished. No one wanted to know. In fact, the DFO routinely suppressed inconvenient research into the causes of the cod decline. In 1995 -- three years after the fishery had collapsed -- he told The Globe and Mail that the decline was due to overfishing. For this simple truth, he earned a formal reprimand. Soon after that, he quit.

"The collapse was all blamed on the environment, on the seals, on the foreigners, when it was primarily Canadians," he said later. "I saw that as the big lie, blaming it on anything but ourselves."

So why are the big sharks going the way of the cod? Blame consumer tastes -- in this case, the Asian craze for shark-fin soup, which is considered a tasty if expensive delicacy. Shark fins sell for hundreds of dollars a kilogram, and shark-fin soup for as much as $100 a bowl. In a practice known as finning, fishermen catch the sharks on the high seas, cut off their fins and throw the carcasses back. It's illegal, but the high seas aren't well policed. As many as 75 million sharks were finned last year, says research team member Julia Baum.

The loss of the big predators cascades through ocean ecosystems. The populations of species on which sharks prey, such as cownose rays, have exploded. In turn, those species devour more of other species farther down the food chain. In North Carolina, for example, the bay scallop fishery has been wiped out, a victim of the cownose rays.

1 of 2 7/27/2008 9:03 PM Document View http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?index=9&s...

It's not too late to save the big fish. Prof. Myers's research has helped to bring about important changes in fishing practices and technology. But nothing much will happen without international laws, internationally enforced. Call it a sort of test case for global warming. If the world's fishing nations can't get together to save the fish, there's no hope for a pact on greenhouse gases.

Meantime, watch out what you're eating from the sea. As someone who loves sushi, this breaks my heart. But it's the ethical thing to do.

[email protected]

Indexing (document details) Author(s): Margaret Wente Document types: News Section: Comment Column Publication title: The Globe and Mail. Toronto, Ont.: Apr 3, 2007. pg. A.15 Source type: Newspaper ISSN: 03190714 ProQuest document ID: 1248846851 Text Word Count 764 Document URL: http://proquest.umi.com.myaccess.library.utoronto.ca/pqdlink?did=1248846851&sid=23&Fmt=3& clientId=12520&RQT=309&VName=PQD

2 of 2 7/27/2008 9:03 PM letters to nature

...... as well as mammals and reptiles, were especially pronounced, and precipitated marked changes in coastal ecosystem structure and Rapid worldwide depletion of function5. Such baseline information is scarce for shelf and oceanic ecosystems. Although there is an understanding of the magnitude of predatory fish communities the decline in single stocks10, it is an open question how entire communities have responded to large-scale exploitation. In this Ransom A. Myers & Boris Worm paper, we examine the trajectories of entire communities, and Biology Department, Dalhousie University, Halifax, Nova Scotia, Canada estimate global rates of decline for large predatory fishes in shelf B3H 4J1 and oceanic ecosystems...... We attempted to compile all data from which relative biomass at Serious concerns have been raised about the ecological effects of the beginning of industrialized exploitation could be reliably industrialized fishing1–3, spurring a United Nations resolution on estimated. For shelf ecosystems, we used standardized research restoring fisheries and marine ecosystems to healthy levels4. trawl surveys in the northwest Atlantic Ocean, the Gulf of Thailand However, a prerequisite for restoration is a general understand- and the Antarctic Ocean off South Georgia, which were designed to ing of the composition and abundance of unexploited fish estimate the biomass of large demersal fish such as codfishes communities, relative to contemporary ones. We constructed (Gadidae), flatfishes (Pleuronectidae), skates and rays (Rajiidae), trajectories of community biomass and composition of large among others (see Supplementary Information for detailed species predatory fishes in four continental shelf and nine oceanic information). In all other shelf areas for which we could obtain data, systems, using all available data from the beginning of exploita- industrialized trawl fisheries occurred before research surveys took tion. Industrialized fisheries typically reduced community bio- place. For oceanic ecosystems, we used Japanese pelagic longlining mass by 80% within 15 years of exploitation. Compensatory data, which represent the complete catch-rate data for tuna (Thun- increases in fast-growing species were observed, but often nini), billfishes (Istiophoridae) and swordfish (Xiphiidae) aggre- reversed within a decade. Using a meta-analytic approach, we gated in monthly intervals, from 1952 to 1999, across a global estimate that large predatory fish biomass today is only about 58 £ 58 grid. Pelagic longlines are the most widespread fishing gear, 10% of pre-industrial levels. We conclude that declines of large and the Japanese fleet the most widespread longline operation, predators in coastal regions5 have extended throughout the covering all oceans except the circumpolar seas. Longlines, which global ocean, with potentially serious consequences for eco- resemble long, baited transects, catch a wide range of species in a systems5–7. Our analysis suggests that management based on consistent way and over vast spatial scales. We had to restrict our recent data alone may be misleading, and provides minimum analysis of longlining data to the equatorial and southern oceans, because industrialized exploitation was already underway in much estimates for unexploited communities, which could serve as the 11,12 ‘missing baseline’8 needed for future restoration efforts. of the Northern Hemisphere before these data were recorded . Ecological communities on continental shelves and in the open Longlining data were separated into temperate, subtropical and ocean contribute almost half of the planet’s primary production9, tropical communities (see Methods). and sustain three-quarters of global fishery yields1. The widespread For each shelf and oceanic community, i, we estimated decline and collapse of major fish stocks has sparked concerns about 2rit NiðtÞ¼Nið0Þ½ð1 2 diÞe þ dið1Þ the effects of overfishing on these communities. Historical data from coastal ecosystems suggest that losses of large predatory fishes, where Ni(t) is the biomass at time t, Ni(0) is the initial biomass

Figure 1 Time trends of community biomass in oceanic (a–i) and shelf ( j–m) points) are shown with superimposed fitted curves from individual maximum-likelihood ecosystems. Relative biomass estimates from the beginning of industrialized fishing (solid fits (solid lines) and empirical Bayes predictions from a mixed-model fit (dashed lines).

Table 1 Meta-analysis of time trends in predatory ﬁsh biomass

r i ( £ 100) d i ( £ 100) Region Individual fit CL Mixed model Individual fit CL Mixed model ...... Tropical Atlantic 16.6 13.5–19.7 16.7 12.1 10.0–14.5 11.9 Subtropical Atlantic 12.9 10.1–15.7 13.0 8.1 6.4–10.2 8.3 Temperate Atlantic 21.4 15.8–26.9 20.3 4.7 3.2–6.9 5.3 Tropical Indian 9.2 7.1–11.4 9.5 17.6 14.9–20.6 16.8 Subtropical Indian 6.5 5.1–7.8 6.8 8.2 5.5–12.3 9.2 Temperature Indian 30.7 23.7–37.8 27.7 5.5 3.9–7.7 6.3 Tropical Pacific 12.1 9.4–14.8 12.4 15.5 13.0–18.6 14.9 Subtropical Pacific 12.8 8.5–17.1 13.5 23.5 18.9–29.3 21.5 Temperate Pacific 20.8 14.3–27.3 20.4 8.2 5.6–12.1 8.5 Gulf of Thailand 25.6 18.2–33.0 22.2 9.3 6.8–12.6 9.8 South Georgia 166.6 2.2–331.1 30.8 20.9 17.5–25.0 16.0 Southern Grand Banks 4.0 2.9–5.1 5.7 0.0 – 10.0 Saint Pierre Banks 5.1 0.1–10.1 6.3 2.7 0.0–36600 7.9 Mixed model mean 16.0 10.3 Mixed model CL 10.7–21.3 7.7–13.9 Distribution 4.5–31.6 4.6–23.6 ......

Two parameters were estimated: ri is the initial rate of decline (in per cent per year), and di the residual biomass proportion at equilibrium (in per cent). Point estimates and 95% conﬁdence limits (CL) are presented for the individual maximum likelihood ﬁts, and for the mixed-effects model that combined all data (see Methods for details). The random-effects distribution (95% limits) provides a measure of the estimated parameter variability across communities.

before industrialized exploitation, and r i is the initial rate of decline of expansion and decline of pelagic fisheries are shown in Fig. 2. to di, the fraction of the community that remains at equilibrium. During the global expansion of longline fisheries in the 1950s to The initial rate of decline in total biomass—that is, the fraction lost 1960s, high abundances of tuna and billfish were always found at the 2ri in the first year—is ð1 2 diÞð1 2 e Þ: Then we combined all data periphery of the fished area (Fig. 2a–c). Most newly fished areas 13 2 using nonlinear mixed-effects models , where ri , Nðmr;jr Þ and showed very high catch rates, but declined to low levels after a few 2 log di , Nðmd;jdÞ; to estimate a global mean and variance of r i years. As a result, all areas now sustain low catch rates, and some and d i. formerly productive areas have been abandoned (Fig. 2d). In shelf In the open ocean communities, we observed surprisingly con- communities, we observed declines of similar magnitude as in the sistent and rapid declines, with catch rates falling from 6–12 down open ocean. The Gulf of Thailand, for example, lost 60% of large to 0.5–2 individuals per 100 hooks during the first 10 years of finfish, sharks and skates during the first 5 years of industrialized exploitation (Fig. 1a–i). Rates of decline were similar in tropical and trawl fishing (Fig. 1j). The highest initial rate of decline was seen in subtropical regions, but consistently highest in temperate regions in South Georgia (Fig. 1k), which has a narrow shelf area that was all three oceans (Fig. 1c, f, i and Table 1). Temperate regions also effectively fished down during the first 2 years of exploitation14. showed the lowest equilibrium catch rates (Table 1). Spatial pattern Less-than-average declines were seen on the Southern Grand Banks

Figure 2 Spatial patterns of relative predator biomass in 1952 (a), 1958 (b), 1964 (c) and longlines set by the Japanese ﬂeet. Data are binned in a global 58 £ 58 grid. For complete 1980 (d). Colour codes depict the number of ﬁsh caught per 100 hooks on pelagic year-by-year maps, refer to the Supplementary Information.

(Fig. 1l) and Saint Pierre Bank (Fig. 1m); these communities may One mechanism that could compensate for the effects of over- already have been affected by intense pre-industrial fisheries15. fishing is the increase in non-target species due to release from By combining all data using a mixed-effects model, we estimated predation or competition21. In our analyses, we see evidence for that the mean initial rate of decline, r i, is 16% per year, and the mean species compensation in both oceanic billfish and shelf groundfish residual equilibrium biomass, d i, is 10% of pre-exploitation levels communities (Fig. 3). According to the longlining data and to early (Table 1). So, an 80% decline typically occurred within 15 years of surveys11,12, blue marlin was initially the dominant billfish species, industrialized exploitation, which is usually before scientific moni- but declined rapidly in the 1950s (Fig. 3a). Simultaneous increases toring has taken place. The proportion of residual biomass, d i, in faster-growing species such as sailfish were observed, followed by showed remarkably little variation between communities (Table 1): a decrease, possibly due to increased ‘bycatch’ mortality (Fig. 3a; the mixed-effects model estimates imply that 95% of communities neither species was targeted by the Japanese fleet). Coincidentally, would have a residual biomass proportion between 5% and 24%. swordfish catch rates increased until these fish became prime We believe that these still represent conservative estimates of total targets of other fleets in the late 1980s. Surprisingly consistent predator declines for the following reasons: (1) pre-industrial patterns of compensatory increase and decline were seen in most removals from some of the shelf communities15; (2) gear saturation pelagic communities (see Supplementary Information). Similarly, at high catch rates in the early longlining data, as well as higher in the North Atlantic demersal communities, we observed rapid initial levels of shark damage leading to an underestimation of initial declines, particularly in large codfishes, but also in skates initial biomass16 (see Supplementary Information); (3) increasing and rockfish. Although the dominant codfishes declined sixfold fishing power of longline vessels over time owing to improved between 1952 and 1970, sixfold increases were seen in the flatfishes, navigation and targeting of oceanographic features17; and (4) which were not initially targeted by the trawl fishery (Fig. 3b). targeting of some migratory species, such as southern bluefin Some increase in the gadoids occurred when implementation of the tuna (Thunnus maccoyii), at their tropical spawning grounds before 200-mile limit in 1977 curtailed foreign overfishing in Canadian widespread exploitation in temperate areas occurred18. Further- waters. However, as in the billfish data, we observed an ultimate more, declines in other large predators such as sharks are not fully decline in all species groups (Fig. 3b) as fishing pressure from captured by our data, but may be of similar or greater magnitude Canadian and other fleets intensified in the late 1980s, leading to than those of bony fishes19,20. the collapse of all major groundfish stocks10. We conclude that some species compensation was evident, but often reversed within a decade or less, probably because of changes in targeting or bycatch. Our analysis suggests that the global ocean has lost more than 90% of large predatory fishes. Although it is now widely accepted that single populations can be fished to low levels, this is the first analysis to show general, pronounced declines of entire communities across widely varying ecosystems. Although the overall magnitude of change is evident, there remains uncertainty about trajectories of individual tuna and billfish species. Assessments of these species are continually improved by the international management agencies. However, most scientists and managers may not be aware of the true magnitude of change in marine ecosystems, because the majority of declines occurred during the first years of exploitation, typically before surveys were undertaken. Manage- ment schemes are usually implemented well after industrialized fishing has begun, and only serve to stabilize fish biomass at low levels. Supporting evidence for these conclusions comes from the United Nations Food and Agriculture Organization (FAO) data set, which indicates declining global catches22 and a consistent decline in the mean trophic level of the catch23, which is a result of removing predatory fishes. Furthermore, on seamounts and on continental slopes, where virgin communities are fished, similar dynamics of extremely high catch rates are observed, which decline rapidly over the first 3–5 years of exploitation24. We suggest that this pattern is not unique to these communities, but simply a universal feature of the early exploitation of ecosystems. Our results have several important management implications. First, we need to consider potential ecosystem effects of removing 90% of large predators. Fishery-induced top–down effects are evident in coastal5 and shelf 25 ecosystems, but little empirical information is available from the open oceans. This is worrisome, as any ecosystem-wide effect is bound to be widespread, and possibly difficult to reverse, because of the global scale of the declines (Fig. 2). Another serious problem in heavily depleted Figure 3 Compensation in exploited fish communities. a, Oceanic billfish community in communities is the extinction of populations, particularly those the tropical Atlantic, showing the catch per 100 hooks (c.p.h.h.) of blue marlin (Makaira with high ages of maturity26. Local extinctions can go unnoticed nigricans; solid circles, solid line), sailfish (Istiophorus platypterus; open triangles, dashed even in closely monitored systems such as the northwest Atlantic27, line) and swordfish (Xiphias gladius; open circles, dotted line). b, Demersal fish let alone in the open ocean. Finally, the reduction of fish biomass to community on the Southern Grand Banks, showing the biomass of codfishes (Gadidae; low levels may compromise the sustainability of fishing, and solid circles, solid line) and flatfishes (Pleuronectidae; open circles, dotted line). Lines support only relatively low economic yields3. Such concerns have represent best fits using a local regression smoother. motivated a recent UN resolution to restore fish stocks to healthy

282 © 2003 Nature Publishing Group NATURE | VOL 423 | 15 MAY 2003 | www.nature.com/nature letters to nature levels4. Our analysis shows that it is appropriate and necessary to 14. Kock, K.-H. & Shimadzu, Y. in Southern Ocean Ecology: The BIOMASS Perspective (ed. El-Sayed, S. Z.) attempt restoration on a global scale, and provides a benchmark 287–312 (Cambridge Univ. Press, Cambridge, 1994). A 15. Hutchings, J. A. & Myers, R. A. in The North Atlantic Fisheries: Successes, Failures and Challenges against which community recovery could be assessed. (eds Arnason, R. & Felt, L.) 38–93 (The Institute of Island Studies, Charlottetown, Prince Edward Island, Canada, 1995). 16. Rothschild, B. J. Competition for gear in a multiple-species fishery. J. Cons. Int. Explor. Mer. 31, Methods 102–110 (1967). Data selection 17. Lyne, V., Parslow, J., Young, J., Pearce, A. & Lynch, M. Development, Application and Evaluation of the For shelf communities, we compiled data from research trawl surveys from the Southern Use of Remote Sensing Data by Australian Fisheries (CSIRO Marine Research, Hobart, Australia, 2000). Grand Banks (43–468 N, 49–538 W) and Saint Pierre Banks (45–478 N, 55–588 W) (ref. 28), 18. Caton, A. E. A review of aspects of southern bluefin tuna biology, population and fisheries. Inter-Am. the Gulf of Thailand (9–148 N, 100–1058 W) (ref. 29) and South Georgia (53–568 S, Trop. Tuna Comm. Spec. Rep. 7, 181–350 (1991). 35–408 W) (ref. 14). All other trawl data sets that we considered (for example, North Sea, 19. Stevens, J. D., Bonfil, R., Dulvy, N. K. & Walker, P. A. The effects of fishing on sharks, rays, and Georges Bank and Alaska) did not capture the beginning of industrialized exploitation. We chimaeras (chondrichthyans), and the implications for marine ecosystems. ICES J. Mar. Sci. 57, included only demersal predators; pelagic species, which were not well sampled by the 476–494 (2000). trawl gear, were excluded. Longlining data obtained from the Japanese Fishery Agency 20. Baum, J. K. et al. Collapse and conservation of shark populations in the Northwest Atlantic. Science 299, 389–392 (2003). were divided into temperate (Atlantic, 40–458 S; Indian, 35–458 S; Pacific, 30–458 S), 21. Fogarty, M. J. & Murawski, S. A. Large-scale disturbance and the structure of marine systems: Fishery subtropical (Atlantic, 10–408 S; Indian, 10–358 S; Pacific, 15–308 S) and tropical impacts on Georges Bank. Ecol. Appl. 8 (suppl.), 6–22 (1998). communities (Atlantic, 208 N–108 S; Indian, 158 N–158 S; Pacific, 10–158 S). These 22. Watson, R. & Pauly, D. Systematic distortions in world fisheries catch trends. Nature 414, 534–536 divisions were based on their dominant species: yellowfin (T. albacares), albacore (2001). (T. alalunga) or southern bluefin tuna (T. maccoyii), respectively, and excluded areas 23. Pauly, D., Christensen, V., Dalsgaard, J., Froese, R. & Torres, F. Jr Fishing down marine food webs. previously fished by the Japanese, Spanish and US fleets. Running the models with Science 279, 860–863 (1998). alternative divisions (^58) did not change the results significantly. The catch rates in each 24. Roberts, C. M. Deep impact: the rising toll of fishing in the deep sea. Trends Ecol. Evol. 242, 242–245 community were determined as the sum of the catches divided by the sum of the effort in (2002). each region in each year. Years with very low effort (,20,000 hooks for the entire region) 25. Worm, B. & Myers, R. A. Meta-analysis of cod–shrimp interactions reveals top–down control in were excluded. Alternative treatment of the data, including removing seasonal effects and oceanic food webs. Ecology 84, 162–173 (2003). taking the average catch rates over 58 £ 58 squares, had little effect on the results. For 26. Myers, R. A. & Mertz, G. The limits of exploitation: a precautionary approach. Ecol. Appl. 8 (suppl.), longlines, we assume that the catch rate is an approximate measure of relative biomass, 165–169 (1998). which is probably conservative because the average individual weights of fish in exploited 27. Casey, J. M. & Myers, R. A. Near extinction of a large, widely distributed fish. Science 281, 690–692 populations tend to decline over time. Our data capture the abundance of larger fishes that (1998). are vulnerable to baited hooks and bottom trawls, respectively. Many smaller species have 28. Casey, J. M. Fish Assemblages on the Grand Banks of Newfoundland. Thesis, Memorial Univ. low catchabilities and are not recorded reliably by these methods. Changes in the longline Newfoundland, Canada (2000). fishery occurred around 1980 when the fishery began to expand into deeper regions; 29. Pauly, D. in Fish Population Dynamics (ed. Gulland, J. A.) 329–348 (Wiley, New York, 1988). however, this was only after the declines in biomass were observed. For more details on 30. Commission for the Conservation of Antarctic Marine Living Resources Statistical Bulletin Vol. 14 species composition, data treatment and interpretation of trends, refer to the (CCAMLR, Hobart, Australia, 2002). Supplementary Information. Supplementary Information accompanies the paper on www.nature.com/nature. Data analysis Our model (equation (1)) assumes that for each community, i, the rate of decline to Acknowledgements We thank J. Casey, A. Fonteneau, S. Hall, J. Hampton, S. Harley, J. Ianelli, equilibrium is exponential with rate r i from a pre-exploitation biomass N i(0), where t ¼ 0 I. Jonsen, J. Kitchell, K.-H. Kock, H. Lotze, M. Maunder, T. Nishida, M. Prager, T. Quinn, G. Scott is the first year of industrialized fishing. Exploitation continues until equilibrium is and P. Ward for data, comments and suggestions, N. Barrowman and W. Blanchard for statistical approached, where a residual proportion, d i, of the biomass remains. We fit this model advice, and D. Swan for technical assistance. This research is part of a larger project on pelagic separately to each community under the assumption of a lognormal error distribution longlining initiated and supported by the Pew Charitable Trusts. Further support was provided by using nonlinear regression (Procedure NLIN in SAS, version 8). We also used nonlinear the Deutsche Forschungsgemeinschaft and the National Sciences and Engineering Research mixed-effects models13 to determine whether the patterns were similar across Council of Canada. communities. Mixed-effect models were fitted by maximizing the likelihood integrated over the random effects using adaptive gaussian quadrature (Procedure NLMIXED in Competing interests statement The authors declare that they have no competing financial SAS). To account for the fact that biomass was recorded in different units (kilotonnes (kt), interests. catch rates), the initial biomass, Ni(0), was assumed to be a fixed effect for each community with appropriate units. For South Georgia, Ni(0) was fixed at the first biomass Correspondence and requests for materials should be addressed to R.A.M. estimate to capture the high initial rate of decline. This first estimate (750 kt; ref. 14) was ([email protected]). considered to be realistic because it was very close to the sum of total removals (514 kt; ref. 30) plus the residual biomass estimate (160 kt; ref. 14) after the first 2 years of fishing. Autocorrelation in the residuals of some time series may cause the standard errors to be underestimated. The results were robust to alternative error assumptions (separate error variances for the time series and alternative error distributions); for example, under the assumption of normal errors, the rate of decline was 13.9% and residual biomass was ...... 10.9%, respectively. Received 25 November 2002; accepted 25 March 2003; doi:10.1038/nature01610. Attractor dynamics of network

1. Pauly, D. & Christensen, V. Primary production required to sustain global fisheries. Nature 374, 255–257 (1995). UP states in the neocortex 2. Tegner, M. J. & Dayton, P. K. Ecosystem effects of fishing. Trends Ecol. Evol. 14, 261–262 (1999). 3. Pauly, D. et al. Towards sustainability in world fisheries. Nature 418, 689–695 (2002). Rosa Cossart, Dmitriy Aronov & Rafael Yuste 4. United Nations. World Summit on Sustainable Development: Plan of Implementation khttp:// www.johannanesburgsummit.org/html/documents/summit_docs/2309_planfinal.html (United Department of Biological Sciences, Columbia University, New York, Nations, New York, 2002). 5. Jackson, J. B. C. et al. Historical overfishing and the recent collapse of coastal ecosystems. Science 293, New York 10027, USA 629–638 (2001)...... 6. Steele, J. H. & Schumacher, M. Ecosystem structure before fishing. Fish. Res. 44, 201–205 (2000). The cerebral cortex receives input from lower brain regions, and 7. Worm, B., Lotze, H. K., Hillebrand, H. & Sommer, U. Consumer versus resource control of species its function is traditionally considered to be processing that input diversity and ecosystem functioning. Nature 417, 848–851 (2002). through successive stages to reach an appropriate output1,2. 8. Pauly, D. Anecdotes and the shifting baseline syndrome of fisheries. Trends Ecol. Evol. 10, 430 (1995). However, the cortical circuit contains many interconnections, 9. Field, C. B., Behrenfeld, M. J., Randerson, J. T. & Falkowski, P. Primary production of the biosphere: including those feeding back from higher centres3–6,andis integrating terrestrial and oceanic components. Science 281, 237–240 (1998). continuously active even in the absence of sensory inputs7–9. 10. Myers, R. A., Hutchings, J. A. & Barrowman, N. J. Why do fish stocks collapse? The example of cod in Atlantic Canada. Ecol. Appl. 7, 91–106 (1997). Such spontaneous firing has a structure that reflects the coordi- 10–12 11. Bullis, H. R. Preliminary report on exploratory longline fishing for tuna in the Gulf of Mexico and the nated activity of specific groups of neurons . Moreover, the Caribbean Sea. Comm. Fish. Rev. 17, 1–15 (1955). membrane potential of cortical neurons fluctuates spontaneously 12. Shomura, R. S. & Murphy, G. I. Longline Fishery for Deep-Swimming Tunas in the Central Pacific, 1953. between a resting (DOWN) and a depolarized (UP) state11,13–16, US Fish and Wildlife Service Special Scientific Report: Fisheries No. 157 (USFWS, Washington, 1955). 13. Davidian, M. & Giltinan, D. M. Nonlinear Models for Repeated Measurement Data (Chapman & Hall, which may also be coordinated. The elevated firing rate in the UP 16 New York, 1995). state follows sensory stimulation and provides a substrate for

What Can Be Learned from the Col apse of a Renewab e Resource? antic Cod, Gadus rnorhua, of Newfoundland and Labrador

Jeffrey A. ~utchin~s'and Ransom A. Myers Department of Fisheries and Oceans, Science Branch, P.8. Box 5667, St. John's, NF A1C 5x7, Canada

Hutchings, J.A., and R.A. Myers. 1994. What can be learned from the collapse of a renewable resources Atlantic cod, Gadus morhara, of Newfoundland and Labrador. Can. J. Fish. Aquat. Sci. 51: 21 26-2146. Temporal changes in demography, population sustainability, and harvest rates support the hypothesis that overexploitation precipitated the commercial extinction of northern cod, Gadus rnorhua, off Newfoundland and Labrador in 1992. Annual estimates of realized population growth (r) indicate that the stock was rarely sustainable at the age-specific survival and fecundity rates experienced since 1962. A twofold decline in annual survival probabilities in the 1980s was concomitant with increased inshore and offshore fishing effort, declining catch rate, and spatial shifts in gillnetting effort from areas of low (inshore) to high (offshore) catch rates. We reject hypotheses that attribute the collapse of northern cod to environmental change. Water temperature was associated neither with juvenile nor adult abundance nor with adult distribution by depth. Harvests equivalent to those of the past decade were sustainable in the nineteenth and early twentieth centuries in a considerably colder environment. An updated analysis of previous work indicates that salinity has little effect on recruitment. We conclude that the collapse of northern cod can be attributed solely to overexploitation and that population sustainability indices such as r provide a means by which the susceptibility and resilience of exploited populations can be assessed and their probability of cesmrnercial extinction reduced. bes modifications terrsporelles des caracteres d6mographiques, de la durabilite des populations et des taux de r6colte soutiennent I'hypothGse selon laquelle la surexploitation a accel6r6 l'extinctiow commerciale de la morue du Nord, Gadus rnorhua, au large de Terre-Neuve et du Labrador en 1992. Les estimations annuelles de croissance rbaliske des populations (r) indiquent que le stock 6tait rarement durable aux taux de survie et de fkcondite par 2ge qui ont exist6 depuis 1962. Une diminution deux fsis plus impor- tante des probabilites annuelles de survie dans les annees 80 co'incidait avec une augmentation de la p@ckec6tiere et hauturiere, avec une diminution des taux de capture ainsi qu'avec les deplacernents spatiaux de la peche au filet maillant des zones 2 faible taux de capture (pgche c6tiere) vers des nones & fort taux de capture (peche hauturigse). Nous rejetons les hypothGses voulant que l'effondrement de la rnsrue du Nord soit attribuable a des changements environnementaux. La tempkrature de I'eau n'etait liee ni 3 l'abondance des juvbniles et des adultes ni A la distribution des adultes en fonctisn de la profondeur. Des recoltes equivalentes a celles des dix dernieres annkes 6taient compatibles avec la durabilite des populations au dix-neuvi&me si&cle et au debut du vingtierne sikcle dans un environnement consi- derablement plus froid. Une analyse recente des travaux anterieurs indique que la salinite n'a que peu d'ef- fet sur le recrutement. Nous concluons que I'effondrement de la morue d,u Nord ne peut &re attribue quf& la surexploitation et que les indices du caractGre durable des populations comme r constituent un moyen d'kvaluer la sensibilit6 et la resilience des populations expioit4es et de rkduire Ia probabilite de leur extinction commerciale.

Received January 26, 1994 Accepted)u/y 21, 1994 (J92254)

esource management is based ow the premise that the of survival and fecundity), population structure (e.g., num- existence sf harvesting regulations better ensures the ber and size of reproductively distinct populations within Rlong-term viability of a population under commercial the geographical area of exploitation), and community ecol- exploitati~nthan does their absence. Ideally, such regula- ogy (i.e., the biological interactions that influence a species' tions should depend upon sound knowledge of the harvested abundance). In practice, the effort allocated to the collection organism's life history (i.e., age- and size-specific schedules of such biological data is limited. Instead, most management agencies concentrate on the formulation of indices of the 'present address: Department of BisBogg.r, BaHhousie University, past, present, and future states sf the population (egg.,abun- Halifax, NS B3H 451, Canada. dance, harvest-induced mortality), metrics assumed sufficient

Can. 9. Fish. Aqlaat. Sci.. Vok. 51, 1983 FIG. 1. Map sf the study region. Cod inhabiting Northwest Atlantic Fishery Organization Divi- sions 29, 3K, and 3& comprise the northern cod stock. Depth contour represents the 300-rn isobath. The broken line separates the inshore and offshore jurisdictional unit areas in 3K and 3L (the Iatter are detailed in the inset). to achieve long-term resource sustainability (Sulland 1983; Overview of the Northern Cod Fishery off Newfoundland Hilborn and Walters 1992). and Labrador The effectiveness sf any management strategy can be difficult to assess. Despite the continued existence of a har- Atlantic cod have been fished in Newfoundland waters vested population, it is impossible to determine whether a since the late fifteenth century (Cell 1982). The fishery was given management strategy is optimal because of the absence largely a hook-and-line fishery until the development sf of a control (i.e., no management of a random sample of cod traps in the 1860s and 1870s (de Loture 1949; Head the same population) and the absence of other treatments 1976; Sinclair 1985). Major technological advances and (i.e., concurrent alternative management strategies on random increased efficiency in harvesting methods continued with the replicates of the same population). It is only when a popu- introduction of bottom trawlers in the early 1900s, particu- lation declines in abundance to a level at which it is not larly after the First World War (de Loture 1949), and nylon economically viable for harvest (commercial extinction) and gill nets in the early 1960s (Templeman 1966). Annual land- when its very existence is threatened that the reliability of a ings of cod in Northwest Atlantic Fishery Organization given strategy can potentially be evaluated. When a har- (NAFO) Divisions 25, 3K, and 3L (hereafter, northern cod; vested population becomes commercially extinct, it is imper- Fig. 1) increased from 100 000 to 150 000 t between 1805 ative that the potential causes of such biological devasta- and 1850, rose to more than 208 000 t during the latter half tion be identified and their relative contributions to the of the nineteenth century, and were frequently in excess of extinction evaluated (Beverton 1990; Ludwig et aH. 1993; 250 800 t from 1900 to 1960 (ICNAF 1952; Harris 1990; Rosenberg et al. 1993). Our objective is to determine the Steele et al. 1992; Lear and Parsons 1993). With the advent degree to which the commercial extinction of Atlantic cod, of long-distance, "factory freezer", stem otter trawlers from Gadus mrhua, from the southern half of Labrador to north- Europe in the 1950s (Warner 1977), catches more than dou- ern Grand Bank of Newfoundland in 1992 was associated bled from 360 008 t in 1959 to the historical maximum of with temporal changes in water temperature, distribution 8 10 000 t in 1968. By 1947, when Canada extended its fish- by depth, and levels of exploitation (e.g., age-specific mor- eries jurisdiction to 200 miles and most long-distance fish- tality, harvest rates, fishing effort, catch per unit effort). ing was effectively eliminated, annual harvests had declined

Can. J. Fish. Aqetat. Sci., Vol. 51, 1994 2127 - spawners ---- recruits

Spawning Stock Biomass (thousand tonnes)

62 7 72 n $2 $7 s2

Year

age 6-9yr Eggs (billions) - age lB13y~ 2oj FIG. 3. (A) Three stock-recruit relationships for northern cod 10 I I 1 I I 1 I (Beverton-HsBt, Ricker, Cushing) including recruitment year classes from 1962 to 1989. (B) Three fitted relationships (as in Fig. 3A) between recruitment and estimated number of eggs for recruitment year classes 1962-89. FIG. 2. (A) Variation in recruitment (numbers of 3-yr-old cod) and spawner biomass (individuals of ages 7 yr and older) of northern cod from 1962 to 1992 (data from Bishop et al. 1993b). stock biomass had an equally large effect on the number of (B) Annual survival (P)of mature northern cod aged 6-9 and 10-13 yr horn 1962 to 1991. Fishing mortality (F) calculated juveniles recruited to the fishery (Fig. 2A); recruitment is pos- from Baird et al. (1992) for 1962-77 and from Bishop et al. itively associated with spawner biomass in northern cod (2 (1 993b) for 1978-9 1; natural mortality is assumed to be constant = 0.73, p = 0.0001, p-value corrected for autocorrelations; at 18% per annum (i.e., A4 = 0.2, as defined by P = e-(F Fig. 3A).

Hypotheses for the Collapse of Northern Cod almost 80% from the 1968 level (Bishop et A. 1993b). Dur- When the moratorium was announced, the collapse of ing the first I1 yr of Canadian management (1978-88), com- northern cod was considered to be sudden, drastic, and unex- mercial landings of northern cod increased from 140 000 pected and was attributed to increased natural mortality to 270 000 toIn 199 1, 1 yr before the Canadian government resulting from unusual environmental conditions, primarily imposed a moratorium on commercial exploitation of north- in the form of cold water temperatures (Lear and Parsons ern cod, landings were 64% less than those in 1988. 1993). A second hypothesis is that colder temperatures The number of hanestable northern cod (i.e., aged 3 yr and throughout the 1980s effected a southerly shift in the dis- older) in 1992 was approximately 3 billion fewer than the tribution of spawning individuals during the 1980s that has number extant in the early 1960s (Baird et al. 199 la; Bishop resulted in the rearing of juveniles in suboptimal habitat et al. H993b). The enormity of this decline can also be (deYoung and Rose 1993). If true, we would expect a neg- expressed through the reduction in biomass of the spawning ative correlation to exist between cod abundance (adults portion of the population (approximated in assessment doc- and recruits to the fishery) and sea temperature. It has also uments as individuals aged '7 yr and older) md in recruitment been suggested that cod have moved to deeper water in (abundance of 3-yr-old cod). Spawner biomass declined recent yeas (Bishop et al. 199%). A short-term, large-scale from an estimated 1.6 million t in 1962 (the first year for emigration to deeper water in the early 1996s would be evi- which estimates are available) to 22 000 t in 1992 (Fig. 2A) dent from a temporal analysis of cod biomass in deep water (Bishop et al. 1993b). This decline was associated with large relative to that in shallower water. Given that total stock fluctuations in annual survival probability (Fig. 2B). Annual failure has not been previously recorded for northern cod survival probabilities for reproductive individuals declined within the past two centuries, these hypotheses make the from roughly 0.6 in the early 1960s to 0.3 in the mid-1978s implicit assumption that environmental conditions experi- and increased to 0.6 again in the early 1980s before declining enced during the early 1994)~~or the 1980~~were tempo- to 0.1-0.2 in the early 1990s. The collapse of the spawning rally anomalous.

2128 Can. J. FFCsh. Aquar. Sci., Vol. 51, 1994 These hypotheses assume either explicitly or implicitly Materials and Methods that an environmental variable is a primary determinant of cod survival and that the dramatic reduction in annual sur- Historical Temperature and Commercial Catch Data vival probabilities throughout the 1980s and early 1990s (Fig. 2B) cannot be wholly explained by increases in fishing Depth-stratified water temperature data have been recorded mortality. When the moratorium on northern cod was approximately twice monthly since 1946 at Station 27 announced on 2 July 1992, it was noted that "the increase in (Fig. 1). Data are generally available at 10-m depth intervals fishing mortality in.. .recent years is inconsistent with the from the surface to 50 m and at every 25 m thereafter to trends in fishing effort by Canadian fleets. The total number the bottom at 175 m. Although small-scale, short-term tem- sf hours fished by the Canadian otter trawl fleet in Div. perature fluctuations in 2J3KL may not be represented by 29t3KL declined consistently from 63,000 [h] in 1988 to these data, they do reflect large-scale variability in tem- 43,000 [h] in 1991" (NAFO 1992, p. 26). This assertion perature and other environmental indices (e.g., areal ice was repeated in the Canadian Fisheries Resource Conser- cover, cold intermediate layer (CIL, volume of

Cm. 9. Fish. Aquat. Sci., Vol. 51, 1994 Ice clearance and air temperature data were smoothed Temporal changes in biomass were documented for the four using a robust locally weighted regression, loess, a method main depth classes in each region in which surveys were recommended for scatterplot data with missing values conducted. These depth classes ranged from BOO to 500 rn, (Cleveland 1979; Hastie and Tibshirani 1998). The value in increments of 100 rn in 23 and 3K, and 57-92, 93-183, at x, fitted by the smoothing procedure is the value of a 184-275, and 276-366 m in 3E. Associations between water polynomial fit to the data using weighted least squares. The temperature and cod biomass in deep water relative to that weight given to (xi, y,) is large if xi is close to x, and small in shallow water were determined by calculating correla- if it is not. tion coefficients between depth-averaged Station 27 temperature anomalies and two indlces of deepwater cod biomass. Research Survey Abundance and Biomass Data The Batter were biomass between 300 and 500 m relative Recent temporal changes in the abundance and biomass of to that between 100 and 300 m in 25 and 3K and biomass adult cod were o,btained from research surveys conducted between 184 and 366 m relative to that between 57 and in autumn by the Canadian Department of Fisheries and 184 m in 3L. Oceans from 1978 to 1992 in 23 and 3K and from 198 1 to 1992 in 3L. Survey estimates of abundance and biomass Catch and Effort Data are based upon the actual number and biomass of cod captured in a series of tows of a bottom otter trawl within each Commercial catch and effort data on Canadian offshore of several depth-stratified sampling strata within each NAFO trawlers were obtained from fishery statistics compiled by division. There are generally 5-30 sets per stratum and there NAFO from 1979 to 1991 (1979-90 data are from NAFO are 24, 23, and 29 strata within Divisions 25, 3K, and 3E, (1984-94); 1991 data are available from NAFO although they have not yet been published). These statistical sum- respectively. The number (or biomass) of cod in division k' is simply the sum of the numbers of cod estimated for all maries report the catch of all species caught in each NAFO division. Catches are further subdivided by country of ori- strata j in that division: gin, by gear type, by vessel tonnage, and by the target species being fished. We restricted our analyses to vessels for which cod constituted the largest biomass of species caught. From 1978 to 1991, nominal effort data were available for The number of cod in stratum j, N,, is estimated as the mean 87-100% of the annual cod biomass caught by otter trawls number of cod captured per tow in stratum j (summed over in 25, 82-100% in 3K, and 91-100% in 3L. Most of the trawls t - 1... x) increased by a proportion equal to the area harvested cod was caught by vessels fishing primarily for of stratum j, Aj, divided by the total area sampled by the cod (as percentages of the annual harvested cod biomass: trawls, i.e., 85-100% in 23, 86-94% in 3K, and 64-88% in 3E). From 1981 to 1991, Canadian trawlers accounted for an average 52% of the Canadian catch and 44% of the total catch of northern cod (calculated from Bishop et al. 1993b). Abundance data were also obtained from depth-stratified Catch and effort data were also analyzed for cod cap- random research surveys conducted by German vessels from tured by traps and gill nets. The data were compiled by 1972 to 1983 in 23 (Messtorff 1984). Their survey designs STACAC (Statistical Co-ordinating Committee for the are comparable with the later Canadian surveys. German Atlantic Coast, Department of Fisheries and Oceans, Ottawa, researchers also employed 30-min tows of otter trawls and Ont., Canada) and are available from 1985 to 1992. These conducted their surveys during late autumn in the same data report catches on a considerably smaller spatial scale strata sampled by the Canadian vessels from 1978 to 1992. than those in the aforementioned NAFO records; data are summarized for 14 unit areas in 25, 11 in 3K, and 14 in 3L. VPA Estimates of Abundance and Biomass Effort is reported as number of trap days and number of Unless identified as being based solely upon research clearances per 100-m gill net. vessel survey data, indices of cod abundance and biomass were those determined from a virtual population analysis Population Sustainability (VPA) conducted using a process called ADAPT (described The instantaneous rate of change of the northern cod stock by Mohn and Cook 1993). For northern cod, this procedure was estimated as r and given by the discrete-time version of combines age-specific indices of population size from both the Euler-Lotka equation commercial and research vessels, or more recently from research vessels only, to estimate historical stock sizes from 1962 to the present (Gavaris 1988; Conser 1993). The age- where lx represents survival from the zygote to the beginning specific groups of cod referred to in the text for which abun- of the breeding season at age x and m, is the number of dance or biomass was estimated from the VPA are recruits female zygotes produced by a female breeding at age x or recruitment to the fishery (abundance of cod of age 3 yr), (Cole 1954; Schaffer 1974). r is frequently used as a mea- spawner or spawning stock biomass (cod of age 7 yr and sure of fitness In evolutionary ecology (Charlesworth 1980; older), and harvestable biomass or abundance (cod of age Stearns 1992; Hutchings 1993). As a measure of the rate 3 yr and older). of change in population abundance, population size at time t + 1 can be estimated from population size at time t from Distribution by Depth of Cod Biomass the equation Nt+, = P\r,er (Caughley 1977; Roff 1992). Thus, Cod biomass was estimated from the autumn research r = 0 for a population that is neither increasing nor decreas- surveys conducted in 2J3KE (data in Bishop et al. 1993b). ing, i.e., sustainable through time.

Can. 9. Fish. Aquat. Sci., Vol. 51, 1984 50-175m (Depth Averaged)

Year FIG.4. Water temperature anomalies from the long-term mean (1946-92) at Station 27, immediately east of St. John's, Newfoundland, at depths of 50, 75, 180, 150, and 175 m and averaged across depths between 50 and 175 m. Solid lines represent annual temperature anomalies; broken lines indicate the maximum and minimum monthly temperature anomalies for each year.

We included age-specific rates of survival, lx, and fecun- (Baird et al. 1991a; Bishop et al. 1993b). For comparison, an dity, m,, for northern cod from 1962 to 1992. Fishing mor- independent review of the northern cod stock suggested an tality estimates for ages 3-13 yr are available in Baird et al. error rate of 3~22%for the overall fishing mortality rate esti- (1991a) for the 1962-77 period and from Bishop et al. mated for 1988 (Harris 1990). (1993b) for the 1978-92 period. Natural mortality per annum Age-specific fecundities were estimated from the fecundity for all ages was assumed to be 18% (Baird et al. 1992; versus weight regressions calculated by May (1967). Weight- Bishop et al. 1993b). To allow for estimation errors in fish- at-age data from the commercial fishery are available from ing mortality, %",we calculated r at F-values 30% greater 1972 to 1992 (Bishop et al. 1993b). Data from 1962 to 1971 and less than those provided in the assessment documents were approximated by the average weight-at-age from 1972

Can. 9. Fish. Aquat. Sci., Voi. 51, 1994 2131 A Canadian Data A -1 A Gemn Data

Temperature Ansrnaty (50-175177)

A Canadian Data 1 A Gem" Data

Temperature Anmaly (50-175m)

0 I'~..I1.'.1'.'. FIG.6. Scatterplots of mature cod abundance against Station 27 1800 8 850 89CH3 1950 2000 water temperature anomaly in NAFO Division 21. Data are from Year autumn research surveys conducted by German and Canadian FIG.5. Temporal variation in water temperatures on the continental vessels from 1972 to 1992. shelf in 3%, date of ice clearance, air temperature, and commercial catch of Atlantic cod in NAFO Divisions 293KE. Shelf tem- abundances). Three stock-recruit relationships were applied peratures in 3L at 180 m (1910-92; MEDS data base) are rep- to the data (Fig. 3B): the Ricker, Beverton-Holt, and Cushing resented by the median with the upper and lower quartiles models (described by Cushing (1971) and Hilborn and Wal- represented by the lines above and below each median, respec- ters (1992)). Survival from birth to age 3 was estimated tively. Ice clearance index (1800-1993) represents the departure from the Ricker and Cushing models which generally encom- in days from the 1964-84 median clearing date at Hopedale, passed the stock and recruit values predicted by the Labrador (data from Newell 1991). Air temperature anomalies Beverton-Hslt model. By using these models, the influence frsm the long-term mean (1894-1 992) recorded by Canadian Atmospheric md Environment Service at St. John's, Newfoundland. of density on juvenile survival (Myers and Cadigan 1993) is Estimated commercial catch of Atlantic cod from the region cor- explicitly included in our estimates of sustainability. responding to 293KL from 1880 to 1992 (data from Hlatchings and Myers 1995). Results to 11992. The similarity between the 1972-92 averaged Interannual Variation in Water Temperature weights-at-age and those estimated from autumn sampling by Significant interannual variation exists among the 47 con- Canadian research vessels in 2J and 3K in the early 1950s secutive years of water temperature data at Station 27 in and early 1960s suggests that such an approximation is a 3L (F[,,,,, ,I = 12-17, p = 0.0001; Fig. 4). The time series reasonable one (unpublished data). Based upon empirical of depth-averaged data indicates that temperatures were data available frsm 9973 to 1992 (Shelton and Morgan below the long-term mean in the early 1970s, the mid-1980s, 1993), we assumed that 0% of females reproduce prior to and the early 1990s (lower right panel in Fig. 4). These rel- age 5 yr, 10% at age 5, 50% at age 6, and 100% at age 7 and atively cold years (1972-74, 1984-85, and 1991-92) are at all subsequent ages until death following reproduction at evident within each depth interval and did not differ in tem- age 25 (fish older than 15 yr constituted a median 1% of perature (6,,7,1= 1.94, p = 0.09: depth-averaged temperatures the total harvested biomass from 1962 to 2991; Bishop et al. from 20 to 175 m did not differ among these years either 1993b). fFI,,7,1= 1.91, p = 0.09)). Thus, as measured by annual, To estimate survival from birth to age 3 yr (ages for which depth-averaged temperature anomalies, the environmental we do not have data), we plotted recruitment (number sf conditions of 1991 and 1992 were also experienced from 3-yr-old cod) against the expected fecundity contribution 1972 to 1974 and during 1984 and 1985. Minimum monthly of the reproductive portion of the population (i.e., the summed anomalies at 50 and 75 rn were lowest in 1991. However, product of age-specific fecundities and age-specific those at BOO, 150, and 175 m in 1991 were similar to or

2 132 Can. J. Fish. Aquat. Sci., Val. 51, 1994 Temperature Anomaly ("6)

Temperature Anomaly ("6) PIG.7. Scatterplots of two indices of recruitment to the northern cod fishery against Station 2'3 water temperature anomaly (depth- averaged from O to 50 m). Upper panel: dependent variable represents millions of cod aged 4 yrs. Lower panel: dependent variable represents residuals from the linear regression of Year log,,(recruitment) versus log,,(spawning stock biomass). Data FIG.8. Temporal changes in cod biomass at four depth intervals are indicated by year class. for which extensive sampling was conducted during autumn research surveys in NAFB Divisions 25, 3K, and 3L. Standard less than those experienced in the early 1970~~the mid- errors of the annual total biomass estimates (all depths included) B980s9 and, for the 175 m depth, the late 1940s. averaged 537% in 25, &41% in 3K, and &I$% in 36, (data from There was no indication that cod landings throughout the Bishop et al. 1993b). nineteenth century were deleteriously affected on the scale of the major fishery collapse experienced in 1991 despite associations persists if the German and Canadian data are environmental conditions colder than those of recent years examined separately (cod aged 6-9 yr: r,,, = 0.39 (p - (Fig. 5). Shelf water temperatures in 3L similar to or less than 0.151, r,,, = -0.13 (g = 0.68); cod aged 10-14 yr: r,,, = those of the early 1990s were experienced in the 1920sq -0.04 (g = 0.89), rGER= -0.08 (g = 0.80). B930s, and late 1940s when commercial landings averaged The association between water temperature and juvenile roughly 250 000 t. Dates of ice clearance from the Labrador cod abundance was examined by plotting numbers of recruits coast and air temperature at St. John's have been consider- to the fishery (i.e., cod aged 3 yr) against the depth-averaged ably earlier and warmer, respectively, in the past several temperature anomalies recorded at Station 27 for the upper decades than they were throughout the nineteenth and early 50 m of the water column (depths at which cod eggs and twentieth centuries when northern cod landings ranged from larvae are found on the Newfoundland Shelf; Anderson and 100 000 to 300 000 t. Thus, landings that were not sustain- deYoung 1993) (Fig. 7, upper panel). The correlation coef- able in the 1980s were sustainable in colder environments ficient between temperature and recruitment is not significant during the nineteenth and early twentieth centuries. (r = 0.19, p = 0.54)- When the effect of spawning stock size on recruitment is removed from the andysis, there is still Water Temperature and Cod Abundance no evidence that recruitment is associated with any range The German and Canadian surveys conducted over 21 yr of water temperature during the first year of life (r = 0.08, (1972-92) in 21 constitute the longest continuous time series p = 0.78; Fig. '7, lower panel). Nor are there significant of research abundance estimates available for northern cod. associations between recruitment (effects of spawner stock Scatterplots of abundance (combined data sets) versus tem- removed) and depth-averaged temperature an;malies in the perature anomaly indicate that abundance of mature cod upper 10 m (r = -0.14, p = 0.58), upper 20 m (r = -0.09, during this period was not associated with water tempera- g = 0.74), or the entire water column from 0 to 175 m (r = ture (Fig. 6; cod aged 6-9 yr: r = 0.08, g = 0.72; cod aged 0.18, g = 0.47). Similar nonsignificant associations exist 10-14 yr: r = -0.03, g = 0.89). The absence of significant between recruitment and temperature experienced during

Can. J. Fish. A~uQ~.Sci., VoB. 51, 1994 2.4 5W-1000GWP 2.4

2.2 2.2

55000 50000- 3. 2.0 3 2.0 - 1.8 -3 z 1.8 5 1- 5 $ llI3 I-- 8.6~ 1.6 a " 2 0 0 1.4 O 1.4 = sm = 3m- 1.2 1.2

25800 1 .0 200(XI- 1.0 I I a I III Ill I II I

1000-2WGRT

Year Year FIG. 9. Temporal variation in nominal commercial fishing effort (hours trawled; solid triangles) and catch per unit effort (CPUE, metric tonnes of cod per trawling hour; open triangles) for Canadian otter trawlers fishing for Atlantic cod in NAFO Divisions 2J3n from 1979 to 1991 (GRT = gross registered tonnage). the second and third years of life (upper 50 m of water, r = time. Biomass at depths 380-40-0 m in 3K increased between 0.23, p = 0.40 and r = 0.46, p = 0.08, respectively). 1989 and 1991 whereas that between 400 and 500 rn was consistently Bow. Shallow water (100-300 rn) biomass in Interannual Variation in Depth Distribution of Cod 3K declined almost 1W-fold over the 15-yr period. In 3L, cod The biomass of northern cod in deep water, relative to biomass in deep water (184-366 m) in the early 1990s was that in shallow water, has not been significantly greater in the lower than or similar to estimates from 1981 to 1989. As with 1990s than in previous years and there is no evidence that the the other two regions, biomass in shallow water (57-183 m) depth distribution of cod is related to water temperature. in 3L declined by almost two orders of magnitude through Any apparent proportional increase in cod biomass in deep the 1980s and early 1990s. Water temperature was not sig- water is due to the near absence of fish in shallow water nificantly associated with deepwater cod biomass (>300 m (Fig. 8). Hn 2J, cod biomass from 100 to 300 rn has declined in 29 ad3K, >I84 m in 3L), relative to biomass in shallower by at least two orders of magnitude since 1978 whereas water, in my of the regions (25: r = -0.35, p = 0.27; 3K: r = biomass between 300 and 500 rn has changed little through -0.28, p = -0.47; 3L: r = -0.08, p = 0.88).

2 134 Carl. J. Fish. Aquab. Sci., Vob. 54, 4994 Temporal Trends in Fishing Effort and Nominal Catch per Unit Effort of Canadian Trawlers The harvesting pressure imposed by offshore trawlers on northern cod was assessed by examining temporal changes in fishing effort (number of trawling hours by Canadian vessels) and catch per unit effort (CPUE, expressed as tonnes of cod captured per hour trawling) (Fig. 9). Catch and effort data are presented for all vessels and for five of the six tonnage classes of Canadian stern trawlers separately (the small- est tonnage class, not shown here, caught less than 1% of the o-' annual trawler harvest from 1979 to 1991). Annually, more OIIIIIIIIll than 90% of the cod biomass caught by Canadian trawlers was harvested by vessels between 500 and 1000 gross registered tonnage (GRT, upper right panel of Fig. 9). From 198 1 to 1988, fishing effort for these vessels more than doubled from 25 544 to 55 923 trawling hours whereas CPUE declined 23% over the same time period. Hours 2Q 1 Inshore 3b k-4 R B trawled and CPUE were negatively correlated for the Offshore 3L E- - Q 500-1 080 GRT vessels (r = -0.90, p = 0.01, p-value corrected for autocorrelation) and for all vessels combined (r = -0.89, p = 0.02). The 54% increase in trawling hours between 1981 and 1991 for 500-1008 GRT vessels was associated with a halving of CPUE. Negative associations between effort and CPUE are also evident for 150-500 GRT vessels and among most years for 1800-2000 GRT vessels. It is noteworthy that during the first 4 yr of operation of the latter vessels, whose harvesting efficiency was generally more than double that of other vessels, a 30% decline in CPUE was associated with an almost fivefold increase in effort. Year FIG. 10. Temporal variation in gillnet catches of northern cod Temporal Trends in Gillnet Catches and Nominal CPUE in (A) 2J3KL and 3L and (B) inshore and offshore unit areas (defined in text) in 3L. Gillnet landings of cod throughout 293KL increased from 11 435 to 47 000 t between 1974 and 1982, declined rapidly between 1982 and 1985 to 20 500 t, and increased again to St. Mary's Bay and along the Southern Shore declined 21% almost 47 000 t in 1989 before decreasing to 17 300 t in whereas catch rate declined 30%. 1991 (Fig. 10A). Temporal variation in gillnet catches in Offshore harvest of cod by gill nets began after the sharp 293KL is reflected largely by catches in 3L. Inshore landings decline in inshore gillnet landings in 293KL between 1982 in 3L increased from 19 500 to 31 000 t in 1987 and and 1985 (Fig. BOB). The majority of offshore cod captured remained at that level for two more years before declining by by gill net were harvested in the Virgin Rocks area in central 50% in each of 1990 and 199 1 (Fig. 10B). Offshore gillnet Grand Bank (unit area 3Lr) (Fig. 1 and 12). The increase catches increased dramatically from 8 t in 1985 to 19 448 t in catch from Virgin Rocks from nil in 1985 to 17 257 t in in 1990, comprising 45 and 71% of the total gillnet catch 1990 was associated with a 53% reduction in catch rate. in 293KL in 1990 and 199 1, respectiveIy. The dramatic spa- This pattern of rapid decline from initially high catch rates tial changes that occurred during the late 1980s in the fixed- that exceeded those experienced inshore to relatively low rates gear fishery are well illustrated by the observation that was evident throughout the Northeast Newfoundland Shelf between 1985 and 1990, offshore gillnet catches of northern (unit areas 3Kbcefg) and throughout north and central Grand cod increased from less than 1 to 18% of the total fixed- Bank (Fig. 12). gear landings of northern cod. Inshore trap and gillnet catches were associated with Temporal Changes in Age-Specific Weight and declining catch rates throughout the latter half of the 1980s Abundance (Fig. 11). Catch rates in the 3K and 3E trap fisheries Temporal changes in age-specific body weight are evident decreased from 1986 to 1991 with the decline clearly evident for northern cod of reproductive age from 1972 to 1992 with by 1989. Notably, a tripling of trap catches in 3E between variability generally increasing with age (Fig. 13). In gen- 1987 and 1990 was associated with a 70% reduction in catch eral, weight-at-age increased from the early 1970s to the late rate. Significant reductions in gillnet catch rate were evident 1970s before declining thereafter. The lowest weights-at-age in Trinity Bay by 1988, Bonavista and Conception bays by occurred between 1972 and 1975 for all age classes except the 1989, and between St. Mary's Bay and the Southern Shore 10- and 11-yr-olds whose lowest weights-at-age were expe- by 1990. Stable or declining gillnet catches were associated rienced in 1992. Although these commercial data represent with declines in catch rate of 80, 60, and 76% in Bonavista the longest continuous time series of weight-at-age data for (1986-89), Conception (1987-89), and Trinity (1985-89) northern cod, it should be noted that the representation of bays, respectively. Between 1986 and 1990, catches from cod from each division differs somewhat annually.

Can. J. Fish. Aquat. Sci., VoL 51, 1994 3K Traps 3L Traps

Bonavista Bay @La) Conception Bay ((3Lf) 7 r 3.5 2.0 7 r 3.3

Southern ShoreBSt. Mary's (3Ljq)

Year FIG. 11. Inshore catches (solid triangles) and catch rate (open triangles) for the trap (3K and 3E) and gillnet (3L unit areas) fisheries for northern cod.

Temporal changes in age structure are evident from age- to similar collapses in age structure, total estimated fecun- specific variation in fecundity contribution to the northern cod dity declined 23% during both 5-yr periods. stock (i.e., age-specific abundance multiplied by age- specific fecundity; Fig. 14). Independent of time, most eggs Annual Variation in the Realized Rate of Natural Increase are produced by 6-, 7-, and 8-yr-old females. The fecun- Age-specific suwival probabilities imposed on northern cod dity contribution of older individuals has declined dramat- since 1962, and corresponding age-specific fecundities, have ically since the 1960s 61962-69) when an annual average rarely been sufficiently high to allow northern cod to sustain 30% of all eggs (46% in 1962) were produced by 10- to themselves (Fig. 15). Independent of the survival estimate to 14-yr-old cod. This percentage dropped by almost one half age 3 (Fig. 15A and 15B), the annual rate of change in cod to 17% in the 1970s before declining further to 12% in the abundance declined steadily from 1962 to 1976, increased to 1980s and 11% in the last 2 yr of the fishery (1990 and 1980 following Canada's jurisdictional extension to 286 miles, 1991). Changes in age structure during the last 5 yr of the and then declined again from 1981 to 1991. The two periods fishery (1987-91) were very similar to those of the 5 yr in which r rose dramatically, i.e., 1974-80 and 1991-92, leading up to the extension of Canada's jurisdiction to were associated with significant reductions in fishing pres- 208 miles (1973-77; Fig. 14, lower two panels). In addition sure by non-Canadian and Canadian vessels, respectively.

2136 Can. .IaFish. Aquat. Sci., Vod. 51, 1994 NE Newfoundland Shelf (3Kbcefg) Northern Grand Bank (3bgk) 1"

Northern Grand Bank (3l-c) Virgin Rocks (3Lr) 0.8 1 4t r

0 Jr----' LO IIIIIIII 85 86 87 88 89 98 91 92

Northern Grand Bank (3Ld) West-Central Grand Bank (3Ls)

Year FIG. 12. Offshore gillnet catches (solid triangles) and catch rate (open triangles) in 3K (all offshore unit areas combined) and in six unit areas throughout 3L. See Fig. 1 for location of unit areas.

Harvestable abundance (cod aged 3 yr and older) from the past three decades. This lack of sustainability coupled 1962 to I992 estimated from yearly estimates of r, inde- with historically high commercial catches and technological pendent of survival to age 3 yr, is highly correlated with expertise, an age structure that has collapsed with respect to estimates based upon the VPA (Fig. f 5C; 1962-77 data number of reproductive age classes and numbers of individ- from Elaird et al. 1991a; 1978-92 data from Bishop et al. uals per age class, declining inshore and offshore catch rates 1993b). Although the VPA- and r-based estimates of abun- during the past decade, and a lack of evidence for environ- dance are not independent (both use the same survival data), mentally related influences on cod survival lend overwhelming their concordance suggests that predicted changes in popula- support to the hypothesis that human overexploitation pre- tion sustainability reflect temporal changes in cod abundance. cipitated the commercial extinction of northern cod.

Discussion Unsustainable Harvesting of Northern Cod Collapse of the Northern Cod Stock The inability of northern cod to achieve sustainability is The demographic changes that northern cod have incurred not surprising given the harvest rates (i.e., commercial since I962 have rarely allowed the stock to sustain itself over catchharvestable biomass) imposed on the stock since 1962

Can. J. Fish. Aquat. Sci., VoL 51, 1994 2147 Year FIG. 13. Weight-at-age data for northern cod of ages 5-15 yr as determined from commercial catches from 1972 to 1992.

(Fig. 16A). A comparison of Fig. 15A, 15B, and 16A indi- TACs were once again based upon fishing mortality less cates that harvest rates less than 17% (the I962 estimate) than Fo.,, it was realized that fishing mortalities throughout will permit the stock to sustain itself. The approximate lin- the 1980s had consistently exceeded B;,., because of over- earity of the stock-recruit relationship for northern cod estimation of stock size (Baird et al. 1991b). Concomitant (Fig. 3A) suggests that the sustainable hmest rate will be rel- with these excessive fishing mortalities were the high pro- atively constant with changes in stock size. The data suggest portions of the commercial catches composed of largely that the stock was sustainable at harvest rates between 19 and prereproductive individuals, i.e., less than 7 yr of age. These 25% from 1978 to 1984. However, this interpretation should percentages increased from 55% in each of 1980, 1981, and be treated with caution, as this period coincided with the 1982 to a mean of 66 2 4(SE)% from 1983 to 1992 (range largest age-specific weights, and hence the largest age-spe- 4644%) (data from annual stock assessment documents for cific fecundities (and thus increased r), since 1972. These the 2J3KL stock). The extent to which TACs since 1977 large weights-at-age may be attributable to the high growth have exceeded the sustainable harvest rate of 17% suggested rates associated with low density for northern cod (Milla and here is illustrated in Fig. 16B. Myers 1990) and may not be representative of the average Perhaps the most direct question related to the relative age-specific weights (or fecundities) experienced by the importance of overfishing to the recent collapse of north- stock. It is also noteworthy that age-specific weights in the ern cod is: How much of the variation in abundance in the late 1980s and early 1990s are similar to or greater than past decade can be explained solely on the basis of changes those recorded between 1947 and 1950 (Fleming 1952). It in harvest rate? Although a temporal analysis of changes should be noted that our estimates of hmest rate are probably in fishing mortality in the 1988s indicates that harvest rates underestimates because they do not include age-specific were exceedingly high, these harvest rate data are based vulnerabilities to the fishery (younger fish tend to be Bess upon estimates of age-specific abundance derived from VPA vulnerable to the fishery than older fish). in which natural mortality is assumed to be constant. A total allowable catch (TAC) was first established for One means of assessing the validity of the harvest rates northern cod by the International Commission for the North- estimated for the 1980s is to calculate changes in the abun- west Atlantic Fisheries (HCNAF) in 1973 (temporal changes dance of northern cod based upon changes in harvest rate in management criteria for northern cod are detailed by and then compare these with independent estimates of abun- Steele et al. (1992) and by Lear and Parsons (1993)). The dance such as those derived from the autumn research TAC was based upon the management strategy of fishing surveys. Annual changes in abundance N from year t to at the maximum sustainable yield, i.e., at F,,, = 0.35. year t + B as a consequence of changes in harvest rate in Increased concern about the conservation of the resource year t, %P,, can be estimated as Hed to the establishment of FO.,(described by Gulland and Boerema 1973) as the target fishing mortality rate in 197'7. The FO.,for northern cod was set at 0.2 which corresponded Thus, abundance is predicted to increase between years t to a harvest rate of 18%. TACs were set at the F,,, level in and t 9 1 by the expected rate of population increase in 1977 and 1978, at 80% Pal from 1979 to 1983, and again at the absence offishing in year t, ei*, and to decline by an 180% FO,,from 1984 to 1986. Following 2 yr during which amount proportional to the harvest rate experienced in that

2 138 Can. 9. Fish. Aqreat. Sca'., Vod. 51, 1994 Age (YO FIG. 14. Estimated age-specific fecundity contributions for northern cod from 1962 to 1991. year (cf. Lockwood 1987). e:* is estimated by assuming for autocorrelation; Fig. 17). This concordance suggests that constant natural mortality of 18% (i.e., M = 0.2) and no 61% of the variation in abundance from 1985 to 1991 can be fishing mortality (i.e., F = 0). accounted by harvest rate and lends strong support to the The longest continual decline in abundance of exploited hypothesis that the decline of northern cod in the 1980s can northern cod in the 1980s occurred from 1985 to 1992 be attributed primarily to overexploitation. This conclusion (Fig. 15C). Predicted changes in abundance during this is supported by an independent analysis which indicates period, as estimated from Equation (51, can be compared that the natural mortality of northern cod did not increase with those derived from the autumn research surveys (for prior to the imposition of the moratorium in 1992 (Myers which annual changes in abundance are a consequence of and Cadigan 1995). both natural and fishing mortality). To account for sampling error, observed mean number of harvestable cod per tow in Long-term Demographic Collapse of Northern Cod year t was approximated by the mean number per tow in By any demographic measure, the viability of northern years t - 1, t, and t + 1, i.e., as a 3-yr running mean (data cod has been seriously threatened since the introduction of from Bishop et al. 1993b). The predicted numbers of cod European-based offshore trawlers in the late 1958s and early per tow are highly correlated with those observed during 1960s. By 1977, when compared with 1962 estimates, (1) har- the research surveys (r = 0.78, p = 0.02, p-value corrected vestable biomass had declined 82% (2 961 080 versus

Can. J. Fish. Aqucmt. Sci., VoL 51, 1994 2139 Cushing Mdel ..+-. --.

Wicker Model ,-- I --

Actual Catch k --A " 1 Hawesting at r=0 A--A

---- O.3 yr survival (Cushing) --- &3 wnrival (Ri6ke3 A estimated from VPP\

OJ Pz 62 64 f33 68 70 72 74 76 78 80 82 84 8f3 $8 90 92 Year Year FIG. 15. Temporal variation in r, the realized rate of natural Fao. 14. (A) Temporal variation in harvest rate (commercial increase (left ordinate), from 1962 to I992 and its relationship to catchlharvestable biomass) of commercial vessels (triangles) and harvestable abundance (cod aged 3 yr and older) from 1978 to in reported commercial catches (squares) from 1962 to 1992. (IS) 1992. At r = 0, the population replaces itself through time. When Changes in actual and estimated sustainable catches (harvest r is greater or less than 0, the population increases or decreases, rate = 1796, see text) for northern cod from 1977 to 1991. respectively, at the annual rates of change indicated on the right ordinate (note that the right ordinates are not linearly scaled). (A) Survival from birth to age 3 yr estimated from the Cushing periods (cf. Fig. 14, lowest two panels) are consistent with spawner-recruit relationship. (B) Survival from birth to age 3 yr this hypothesis. Given the near collapse of the stock in estimated from the Ricker spawner-recruit relationship. (C) Tem- 1977, it is not surprising that there was little margin for poral change in harvestable abundance as estimated by VPA error in establishing sustainable harvest rates in the early (Bishop et al. 199%) and as calculated assuming annual rates of change in population size corresponding to the annual esti- 1980s. However, harvest rates in the 1980s greatly exceeded mates of r with survival from birth to age 3 yr estimated from the the targeted Fo., level, largely because of overestimation of Ricker and Cushing stock-recrui t relationships. stock size (described by Baird et al. (1991b) and by Hilborn and Walters (1992, p. 533-535) and discussed further below) coupled with great uncertainty in abundance estimates derived 526 000 t), (2) spawner biomass had declined 94% (1.6 mil- from the research surveys (standard errors of 3040% of lion versus 93 000 t), (3) recruitment had declined 84% (2 bil- the mean are not uncommon; data in Bishop et al. 1993b). lion versus 268 million), (4) fecundity contribution of 10- to 14-yr-old fish had declined from 46 to I$%, and (5) harvest Changes in Catch Rate and Spatial Allocation of Effort as rates had yet to attain levels at which the stock was sus- Metrics of Stock Health tainable. For most populations, the 82% reduction in har- The decline in northern cod abundance in the 1980s was vestable northern cod biomass experienced between 1962 reflected by changes in fishing effort and catch rate. During and 1977 would have been considered a collapse! If not for the decade preceding the northern cod moratorium, a twofold the large reduction in harvest rate by 1978 (less than half the decline in annual survival probability (cf. Fig. 2) was asso- 1975 rate of 5 1%) concomitant with the establishment of ciated with increased inshore and offshore fishing effort, a the 280-mile limit and the fortuitously high recruitment (rel- spatial change in allocation of gillnet effort, and dramatic ative to spawner abundance) provided by the 1978-8 B year declines in catch rate of inshore and offshore fishing gear. classes (cf. Fig. 'B), northern cod would probably have col- The observed doubling of hours trawled and the halving of lapsed by 1980. The remarkably similar patterns of decline trawler catch rate may be conservative estimates of the tem- in P' (Fig. Is), in age-specific fecundity contributions, and in poral increase in fishing effort and decline in harvesting total fecundity between the 1973-77 and 1987-91 time efficiency (cf. Rothschild 1977). One hour of trawling in

Can. J. Fish. Aqstat. Sci., Vob. PI, I994 A oht2~ed ------. observed (3 yr running mean) r3----E predidod (based on harvest rates)

Year FIG. 1'7. Mean number of harvestable cod (cod aged 3 yr and older) per tow in 2J3KL from 1985 to 1991 as observed fr~m autumn research surveys and as predicted from annual estimates sf harvest sate.

1991 may have exerted considerably more mortality on the stock than one trawling hour in 1981 because of increased ability to locate and harvest cod through advances in technology and learning by those exploiting the resource. Temporal changes may also, however, have been affected by changes in trawling practices and gear operation which can combine Hawestable Biomass (thousand tonne$) to decrease trawling effort (e.g., the employment of win- FIG. 18. Relationship between catch rate (estimated from a mul- dows on trawls to allow for increased escapement of fish). tiplicative model by Bishop and Gavaris 1982) and harvestable Increasing inshore catches combined with declining catch biomass of northern cod (biomass of cod aged 3 yr and older) rates were indicative of dramatic increases in effort in the from I962 to 1981 (upper panel) and between nominal catch mid- to late 1980s (and possibly as early as the 1960s; cf. per unit effort (CPUE) of Canadian stern otter trawlers and har- Templeman 1966). Initiation of the use of gill nets offshore vestable biomass from I982 to 1991 (lower panel). in 1987, where catch rates declined at even faster rates than they did inshore, would appear to have been a direct con- High trawler catch rates can be maintained despite declin- sequence of declining catch rates inshore. Thus, despite ing stock size for the simple reason that fishers do not exploit increases in both gillnet and trap catches of northern cod fish in a random manner. Increased ability to locate large from the mid-1988s (Fig. 18; Bishop et al. 1993b), these assemblages of fish coupled with an apparent increase in patterns did not reflect the health of the stock because they the concentration of northern cod in the 1980s (Bishop et al. obscured the underlying dynamics of spatial and temporal 1993b) can also lead to nonlinear relationships between catch changes in the allocation of effort. rate and stock abundance, thus violating one of the implicit The influence of changes in gear technology on catch assumptions of most analyses of commercial catch data rates of northern cod, and on management's perception of (Hilborn and Walters 1992). Such nonlinearity is evident in stock health, has not received the attention it warrants. It plots of catch rate against harvestable biomass of northern cod is clear that the ability of inshore fishers to catch fish has during the 10 yr immediately preceding the moratorium increased dramatically with time, particularly during the (1982-91) and during the previous 20 yr (1962-8 1). 1980s, and any interpretation of temporal changes in land- (Fig. 18). Catch rates from 1982 to 1991 represent the nom- ings should reflect these changes in effort. For example, inal CPUE estimated from 508-1080 GRT Canadian trawlers; echo sounders can permit the employment of greater number catch rates from 1962 to 1981 were those estimated by Bishop of cod traps per fisher because of the avoidance of hauling and Gavaris (1982). For both time periods, a curvilinear empty traps. Sounders also reduce the time handline fishers relationship between CPLTE and harvestable biomass (HB) spend on locating cod. Throughout the 1980s, there was (CPUE = ~HB~)provided a significantly better fit to the increased use of "Japanese" cod traps whose design allows data than did the model with f3 constrained to be 1 (1962-81 for reduced escapement of fish and permits their placement in data: CPUE = 0.001~~'.~~,Fi2.171= 64.6, p e 0.00001; areas unsuitable for regular cod traps (Neis 1992). Advanced 1982-91 data: CPUE = 0.070HB0.48, FI,,,! = 69.3, p = navigation equipment such as Loran C enables fishers to 0.00003) such that the probability of overestamating abun- record electronically the location of large fish assemblages, dance increases as GPUE declines (note the similarity in the sites of previously large catches, and the precise orienta- slopes, P, of the two models). The first-order autocorrelation of gillnet sets. The necessity of having to increase effort tion coefficient was significant (p= 0.8006) in the 1962-81 significantly throughout the 1970s and 1980s in order to data but not for the 1982-91 data. Thus, the parameters for maintain catches is amply reflected in interviews with inshore the model describing the 1962-8 1 data were estimated under cod fishers (e.g., Neis 1992; Davis et al. 1994). the assumption that the error term is an autoregressive process.

Can. J. Fish. Aquczf. Sci., Val. 51, 194 We also assumed that all estimation errors were in CPUE was characterized by slower than average growth whereas (following Richards and Schnute 1986). If estimation errors better than average growth has mcumed since 8925; Jacoby and are assumed to be in HB, similar and highly significant Cook 1983). regressions are obtained. The pattern of nonlinearity illustrated Despite the colder environment from 18864 to the 1920s, it in Fig. 18 is expected in fisheries (such as the offshore was possible to sustain a fishery of the size that was not trawler fishery for northern cod) where search is highly effi- sustainable in the 1980s. There is no evidence of extra- cient, effort is concentrated in areas in which fish are most ordinarily high natural mortalities leading to a major stock abundant, adfish remain concentrated as abundance declines collapse in the past two centuries of the kind experienced in (Hilborn and Walters 8992). There is a growing literature the early 19964s. Extant historical records of mass cod which indicates that P is less than 1 for many gadoid stocks mortalities (Templeman 1965) were reported during years with the result that fishing mortalities can remain high (1876, 1934, 1960) in which catches were relatively high despite declines in stock size (e.g., Cooke and Beddington (- 140 000, -260 000, and 459 000 t, respectively). If the 1985; Crecco and Overholtz 1990; Rose and Leggett 1991). reduction in cod abundance in the 1980s and early 1990s Increased search and harvesting efficiency of Canadian was due to increased natural mortality resulting from cold trawlers contributed to the serious overestimates of northern temperature, then similar population declines should have cod abundance in the 1980s. This is well illustrated from been evident during years with similarly cold temperatures 197%to 1981 (Fig. 18, upper panel) in which a more than (e.g., 1972-74, 1984-85, 1991-92). Despite encompassing threefold increase in catch rate was associated with a rela- all three cold periods, the longest continous research time tively small increase in stock abundance. The potential for series (in region 25) did not yield a significant correlation overestimation of stock size is clear given that technologi- between water temperature and cod abundance. It is also cal advances had increased catch rates from 1979 to 1981 to worth noting that the large 1.7"C decline in water temperature levels previously realized in the 1960s when abundance was on St. Pierre Bank (NAFO division 3Ps) off the south coast considerably higher. From 1978 to 1986, the abundance of of Newfoundland from the 1981-84 average of l.4"C to the northern cod was usually approximated by the midpoint of 1985-91 average of -0.7"C (mean temperature at 50 m the VPA estimates derived from both commercial CPUE between January and June; data in Hutchings and Myers data and data from research vessel surveys (Baird et al. 1994) was not associated with a precipitous decline in cod 199 1 b). However, abundance estimates based upon the com- biomass (Bishop et al. 1993a). mercial data indicated that the stock had increased three- Water temperature and depth distribution ~f cod fold from 1978 to 1988 whereas those based upon the Data from the autumn research surveys are not consis- research surveys suggested that the stock had changed little tent with a directed movement of large numbers of cod to in size (Baird et al. 1991b; Hilborn and Walters 1992, deeper water (Fig. 8). Any apparent increase in the pro- p. 533-535). The main consequence of this overestimation portion of cod biomass in deep water in the late 1980s and of stock size was that actual fishing mortality rates exceeded early 1990s can be attributed to the near absence of cod in the targeted B;,,, level of F = 0.2 more than twofold from shallow water. In addition, the distribution of cod with depth 1978 to 1983 (average of F' = 0.41 k 0.03 (SE) for cod aged appears to be unrelated to water temperature. Although the 7-9 yr) and more than threefold from 1984 to 1989 (average water temperature data in our analysis were those from of F' = 0.65 & 0.08) (data in Bishop et al. 1993b). Station 27, and as such do not extend to some of the deeper depths at which fish were caught in the research surveys, Relative Importance of Environmental Change to the our results agree with those of Lilly (1994) who examined the Collapse of Northern Cod relationship between bottom temperatures recorded at the W~terte~nperature and secstaifzabke harvests time of the research surveys and the abundance of cod in Mow much of the variation in northern cod abundance in the the shallowest strata in division 25. We concluded that there decade preceding the moratorium can be attributed to vari- was no support for the postulate that the reduced abundance ability in the environment? More specifically, to what extent of cod in the north and west sections of 25 and 3K was the did "ecological factors" in 1991 (Lear and Parsons 1993) or result of avoidance of cold water. Hutchings and Myers cold temperatures throughout the 1980s (deYoung and Rose (1994) could also find no association between late and 1993) predicate the collapse in cod abundance? Long-term winterispring temperatures and cod biomass on the shelf data for a variety of environmentd indices including the NOA relative to that on the slope in 3L (the latter being a metric index (data on sea level air pressure) (Drinkwater 1994), of the spring migration from the slope to shelf). areal extent of the CIL on the Northeast Newfoundland Shelf Water temperature and recruit~nent (Brinkwater 1994), Station 27 water temperatures (Fig. 4), We are unable to document any association between water 1B8 m depth water temperatures throughout 3L, pack ice per- temperature and recruitment of cod to the fishery (Fig. 7). sistence off Labrador, and air temperature in St. John9s(Fig. 5) Of the five cold years for which data are available (1972-74, indicate that while it was relatively cold and ice cover rela- 1984, 1985), two year classes were greater than average tively extensive in 199 1, similar conditions had been expe- whereas three were less than average (Fig. 7, lower panel). rienced during the previous two decades and considerably Myers et al. (1992) were also unable to find any consistent colder conditions had prevailed throughout the nineteenth relationship between Station 2% water temperature or the and early twentieth centuries. Evidence of a colder environ- extent of the CLwith either VPA or research survey estimates ment in the 1800s is also supported by ground borehole data of recruitment. In contrast, deYoung and Rose (1993) reported from Newfoundland (Beltrami and Mareschal 1992) and by a positive correlation between northern cod recruitment and long-term (1550-1978) tree-ring data from northern Canada temperature between 1972 and 1988. Their exclusion of data md Alaska (which indicate that most of the nineteenth century from 1962 to 197 1 notwithstanding, deYoung md Rose (1993)

2242 Can. J. FFish. Aquat. Sci., Vol. 51, 1594 removed the effects of spawner abundance on recruitment from 1976 to 1987 when spawning stock biomass was by dividing the number of 3-yr-olds by the number of cod included in the analysis. We repeated their multiple regres- aged 6 yr and older. This means of accounting for changes in sion analysis because the most recent VPA estimates of the fecundity of a stock can be justified only if the age and recruitment and spawner biomass (Bishop et al. 1993b) indi- size distributions of reproductive individuals remain con- cated that recruitment from the 1984 to 1988 year classes was stant with time, i.e., if fecundity is a function of the numbers substantially less than had been estimated in 1992 (Baird of individuals and neither their age nor size. It is clear, how- et al. 1992). The percentage reductions in the 1993 recruit- ever, that both mean age and bdy size have declined over the ment estimates relative to those from 1992 were 16% (1984 past two and three decades (cf. Fig. 14). Decreasing age and year class), 23% (1985), 42% (1986), 55% (1987), and 43% body size will have the effect of continually underestimating (1988). recruitment with ever-increasing bias when number of recruits Our reanalysis indicates that salinity has little effect on is divided by number of spawners. If the effect of spawner recruitment relative to that of spawner biomass. Compar- biomass (a more reliable metric of fecundity than abundance) ing one-variable models, the r2 of the regression of log- on recruitment is removed from the analysis, there is no sig- transformed spawner biomass against log-transformed recmit- nificant association between recruitment and water temperature ment (2 = 0.39, p = 0.0004; untransformed recruitment and (depth-averaged over 0-50 m) for the 1972-89 year classes spawner biomass data: 2 = 0.73, p < 0.0001) is highly sig- of northern cod (r = 0.3 1, p = 0.210). Again, if water tem- nificant whereas that of the regression of salinity against perature in the upper 50 m (the usual location of cod lar- log-transformed recruitment is npt (r2 = 0.11, p = 0.08; vae; Anderson and deYoung 1993) has a significantly detri- untransformed recruitment data: r- = 0.15, p = 0.04). The mental effect on larval survival, a significant decline in marginal significance of salinity suggested by the regres- recruitment in 3Ps should have been observed following the sion of salinity against the untransformed recruitment data 1.4"C decline in temperature (greater than any annual decline is not evident in the multiple regression model (i.e., recruit- recorded at Station 27) at 50 m between 1984 and 1985. ment = cx(spawner biomass) + p(salinity) + E). Following However, there is no significant association between water the stepwise addition of spawner biomass, inclusion of salin- temperature (Januq through June at 50 m; data in Hutchings ity does not significantly improve the r' of the multiple and Myers 1994) and the residuals from the regression of regression for either the transformed (p = 0.10) or untrans- log ,,(recruitment) against log,,(spawner biomass) (data in formed data (p = 0.07). Bishop et al. 1993a) for cod in 3Ps from 1972 to 1989 (r = Resistance and resilience to environtmemtal variatio~~ 0.11, p = 0.662). We conclude that, relative to the effect of spawner biomass, Et has been argued that cold temperatures effect southerly neither temperature nor salinity had a significant influence shifts in the location of spawning cod and lead to recruitment on recruitment of northern cod prior to the moratorium in failures (deYoung and Rose 1993). Empirical support for 1992. However, one consequence of the dramatic reduc- the argument is primarily of three kinds. The first was an tions in abundance experienced by northern cod over the apparent association between water temperature and recruit- past three decades may have been increased susceptibility to ment which, as outlined above, is problematic in its inter- environmentally induced stochasticity in age-specific sur- pretation. Second, cod larvae in 2J3KL were purported to vival rates (Harrison 1979; Lande 1988). Populations with be more southerly distributed in a cold year (1935) than in low r can have reduced ability to return to their equilib- a warm year (1934). However, this observation must be rium density following a disturbance from equilibrium, i.e., tempered by the observation that there was no difference they have low resilience (Holling 1973; May et al. 1974; in water temperatures on the Northeast Newfoundland Shelf Harrison 1979; Pimm 1991). Low resilience of northern cod in 1934 and 1935 (MEBS data base; t!,,, = 0.95, p = 0.35). is implied by their low intrinsic rates of increase during the Third, deYoung and Rose (1993) also argued, citing data 1970s and mid- to late 1980s (Harwood 1978; Harrison on spring distributions of cod on the Northeast Newfound- 1979). Thus, the negative association between resilience Hand Shelf, that cod were more southerly distributed in two and harvesting mortality (Beddington 1978; Harwood 1978) cold years (1984 and 1985) than in two warm years (1986 may have increased the susceptibility of cod in recent years and 1987). However, given that the hydroacoustic samples to changes in water temperature to which larger, more upon which these data are based were not conducted north resilient populations would not have been affected. Thus, of 51"30rN in 1984 and 1985 because of ice conditions, the the extremely low abundance of northern cod in the 1990s finding of cod north of this latitude in 1986 and 1987 does raises justified concern that increased vulnerability to both not constitute evidence that cod are more northerly distrib- fishing (within and without the 200-mile limit) and natu- uted in warm years (a caveat noted also by deYoung and rally occurring environmental variation may significantly Rose 1993). The claim that cod are more widely dispersed increase the probability of extinction of this stock. in warm years cannot be assessed in the absence of data on Population resilience would also be expected to decline actual locations and sampling effort of the ship(s) involved. with increased variability in juvenile survival. Based upon Sali~~ityand recruitment their finding that age is positively correlated with spawn- Even if there is an effect of water temperature on recruit- ing duration in cod, Hutchings and Myers (1993) identified ment, although not detectable with data presently available, a mechanism by which the size-selective mortality against it will likely be small relative to that of the size of the larger, older individuals characteristic of most fisheries can spawning stock. This can be illustrated by an analysis of increase variability in recruitment. Selective mortality against the effects of salinity on northern cod recruitment. Based larger individuals is reflected by the observation that relative upon a model proposed by Sutcliffe et al. (1983), Myers to the early 196Os, the expected fecundity contribution of et al. (1993) found that salinity experienced during the sec- older cod (15-20 yr) in the late 1980s had declined by two ond year of life was significantly related to recruitment orders of magnitude relative to that of younger (7-9 yr)

Can. J. Fish. Aquat. Sci., Vok. 51, 1994 individuals, i.e., for every 400 eggs produced by younger the history of fisheries management (e.g., California sardine cod, older cod produced 48 eggs in the early 1968s but only (Radovitch 198 1); Peruvian anchovy (HiBbom and Walters 4 eggs in the late 1980s (Fig. 1B in Hutchings and Myers f 992); Mricmarmibiara pilchard (Cram 1981)) should provide 1993). Given that younger cod spawn for a shorter period ample justification for politicians, policy-makers, industry, than older cod (Hutchings and Myers 19%), this bias towards and management to limit the urge to attribute resource col- younger ages coupled with a decline in the number of age lapses to vaguely understood or even imagined environ- classes during spawning would be expected to shorten the mental causes. The ecological and socioeconomic conse- effective spawning season, reducing the likelihood that lar- quences of so responding to repeated failure are too great. vae could initiate feeding during the period of peak zooplankton abundance and thereby increasing variation in juve- Acknowledgements nile survival. We very much appreciate the assistance of those presently Conclusions involved in the assessment of northern cod, notably Claude Bishop, Eugene Murphy, and Don Stmsbury. Nick Bmowrnan and Our analyses of realized population growth (r) indicate Noel Cadigan provided invaluable statistical and computing that northern cod have rarely been fished at sustainable lev- assistance; David Arenillas assisted us in digitizing some of the els since at Beast 1962. Overfishing by long-distance trawlers data. We thank John Newell for permission to use the ice clear- in the 1960s and 1970s had reduced the stock to near com- ance data presented in Fig. 5 and Darryl Janes for compiling mercial extinction in 1977. Since Canada's extension of and updating these data. Ken Drinkwater provided the air tem- fisheries jurisdiction to 200 miles, two factors were of prime perature data in Fig. 5. Financial support for this work was pro- importance in contributing to the overexploitation of the vided by the Northern Cod Science Programme and a NSERC stock from 1977 to 1991. First, management estimated that Visiting Fellowship to J.A.H. Carl Walters provided extremely use- ful comments and criticism ow an earlier version of the manu- recruitment from 1977 would equal the average maintained script. Bruce Atkinson, Ray Beverton, Claude Bishop, Michael from 1962 to 1972 (see Steele et al. (1992) and Lear and Fogarty, Richard Haedrich, George LiBBy, Gordon Meetz, Bill Parsons (1993) for more details). Given that the stock (i.e., Montevecchi, Doug Morris, Barbara Neis, Andy Rosenberg, harvestable abundance) was three to four times larger in Nancy Shackell, Chris Taggart, and George Winters also pro- the 1960s than in 1977, and that recruitment was not cor- vided very helpful comments and discussion. rected for changes in spawner biomass, the predicted rate of growth of the stock was greatly overestimated (see harvest References predictions in Kirby 1982). Nonetheless, the predicted growth ANDERSON,J.T., AND B. DEYOUNG.1993. Application of a I-dimensional sf the stock Bed to markedly increased industrial and govem- model to vertical distributions of cod eggs and larvae on the nsrth- ment investment which fuelled a socioeconomic and politi- east Newfoundland shelf. ICES Syrnp. Cod and Climate Change, cal optimism in the fishery whose momentum could not Poster 1 1. 14 p. easily be abated. The second factor was the overestimation BAIRD,J.W., C.A. BISHOP,W.B. BRODIE,AND E.F. MURPHY.8 992. An assessment of the cod stock in NAFO divisions 2J3KL. NAFB Sci. of stock size (described earlier) and the concomitant excess Counc. Res. Doc. 92/18, Ser. No. N2063. of actual fishing mortality over targeted rates. As noted by BAHRD,J.W., C.A. BISHOP,AND E.F. MURPHY.B991a. An assessment of Finlayson (8994), reliance upon commercial data, whose the cod stock in NAFB Divisions 2J3KL. CAFSAC Wes. Doc. 91/53: catch rates indicated that the stock was increasing in size, to 84 p. "fine-tune" the VPAs (at least until 1986) was probably a BAIRD,J.W., C.A. BISHOP,AND E.P. MBIRPHY.1991b. Sudden changes in the perception of stock size and reference catch levels for cod in north- reflection of management's prediction of rapid growth sf eastern Newfoundland shelves. NAFO Sci. Counc. Stud. 16: 111-1 19. the stock in the late 1970s. BEDDINGTON,J.R. 1978. On the risks associated with different harvesting The temporal changes in demography, population sus- strategies. Rep. Int. Whaling Comm. 28: 165-167. tainability, harvest rates, and inshorelsffshore catch rates BELTRA~II,H.. AND J.-C. MARESCHAL.1992. Ground temperature changes in eastern Canada: borehole temperature evidence compared with proxy documented here provide strong evidence that over- data. Terra Nova 5: 21-28. exploitation was the primary cause of the collapse of northern BEWRTON,R.J.H. 1990. Small marine pelagic fish and the threat of fishing; cod in the early 1990s. The inability to identify unambigu- are they endangered? J. Fish Bid. 37: 5-16. ous and significant associations between water temperature BISHOP,C.A., AND S. GAVARHS.1982. Assessment of the cod stock in and both spatial and depth-related indices of juvenile and NAFO Divisions 2J3KL. NAFO Sci. Counc. Res. Doc. $2/QI/68, Ser. No. N561: 12 p. adult cod abundance (Myers et al. 1992; deYoung and Rose BISHOP,C.A., E.F. MURPHY,AND M.B. DAVIS.1993a. An assessment of 1993; Lilly 1994; present paper), the collapse in population the cod stock in NAFO Subdivision 3Ps. DFO Atl. Fish. Wes. Doc. structure defined primarily by fewer reproductive age classes 93/70: 39 p. and fewer individuals per age class (Fig. 14), the observation BISHOP,C.A., E.F. MURPHY,M.B. DAVIS,J.W. BAIRD,AND G.A. ROSE. 1993b. An assessment of the cod stock in NAFO Divisions 2Jf 3Kb. that cod did not have anomalously low age-specific weights NAFO Sci. Counc. Res. Doc. 93/86, Ser. No. N2271: 51 p. in the early 1990s (Fig. 13; Fleming 1952), the observation CAUGHLEY,G. 1977. Analysis of vertebrate populations. Wiley $s Sons, that the population decline can be predicted solely from New York, N.Y. 234 p. harvest rates and cannot be attributed to increased natural CELL,G.T. [ED.] 1982. Newfoundland discovered: English attempts at mortality (Fig. 17; Myers and Cadigan 1995), the low mount colonisation, 1610-1630. The Hakluyt Society, London. 3 10 p. CHARLESWORTH,B. 1980. Evolution in age-structured populations. Cambridge of recruitment variability that can be attributed to water Unsversity Press, Cambridge. 300 p. temperature and salinity, and the fact that large harvests CLEVELAND,W.S. 1979. Robust locally weighted regression and smoothing were sustainable during a colder environment in the nine- scatterplots. J. Am. Stat. Assoc. 74: 829-836. teenth and early twentieth centuries underscore our postulate COLBOURNE,E., S. NARAYANAN,AND S. PRINSBNBERG.1994. Climatic change and environmental conditions in the Northwest Atlantic during that the environment contributed relatively little to the col- the perisd 1970-1993. ICES Mar. Sci. Syrnp. (In press) lapse of northern cod relative to that imposed by the fishery. COLE,L.C. 1954. The population consequences of life history phenom- The cod collapse and previous commercial extinctions in ena. Q. Rev. Biol. 29: 103-1 37.

Can. .laFish. Aquat. Sci., V01. 51, 1998 CQNSER,R. 1993. A brief history of ADAPT. p. 83-87. Bn R.K. Mohn Atlantic fisheries. Supply and Services Canada. Ottawa, Ont. and R. Cook [ed.] Introduction to sequential population analysis. LANDE,R. 1988. Genetics and demography in biological conservation. NAFO Sci. Counc. Stud. No. 17, Dartmouth, N.S. Science (Wash., D.C.) 241: 1455-1459. COOKE,J.G., AND J.R. BEDDINGTON.1985. The relationship between catch EEAR,W.H., AND L.S. PARSONS.1993. History and management of the rates and abundance in fishes. IMA J. Math. Appl. Med. Biol. 2: 1-15. fishery for northern cod in NAFO Divisions 25, 3K and 3E, p. 55-89. CRAM,D. 1981. Hidden elements in the development and implementation In L.S. Parsons and W.H. Lear [ed.] Perspectives on Canadian marine of marine resource conservation policy: the case of the southwest fisheries management. Can. Bull. Fish. Aquat. Sci. 226. Mrica/Nmibian fisheries, p. 137-156. In M.R. Glmtz and J.D. Thompson LILLY,G.R. 1994. Predation by Atlantic cod on capelin on the southern [ed.] Resource management and environmental uncertainty. Wiley Labrador and northeast Newfoundland shelves during n period of & Sons, New York, N.Y. changing spatial distributions. ICES Mar. Sci. Symp. (In press) CRECCO,V., AND W.J. OVEWHOLTZ.1990. Causes of density-dependent LOCKWOOD,S.J. 1987. A simple method for analysing trends in recruitment. catchability for Ceorges Bank haddock Melanogrammus aeglefinus. J. Cons. Int. Explor. Mer 43: 279-284. Can. J. Fish. Aquat. Sci. 47: 385-394. LUDWIG,B., R. HIL.RORN,AND C. WALTERS.1993. Uncertainty, resource CUSHING,B.H. 1971. The dependence of recruitment on parent stock in exploitation, and conservation: lessons from history. Science (Wash., D.C.) different groups of fishes. J. Cons. Int. Explor. Mer 33: 340-362. 260: 17, 36. DAVIS,M.B., P. L~JNDRIGAN,AND P. RIPLEY.1994. A description of the MAY,A.W. 1967. Fecundity of Atlantic cod. J. Fish. Res. Board Can. 24: cod stock structure in Placentia Bay, NAFO Subdivision 3Ps. BFO 1531-1551. Atl. Fish. Res. Doc. 94/32: 14 p. MAY,R.M., G.R. CONWAY,M.P. HASSELL,AND T.R.E. SOUTHWOOD.1974. DE LOTURE,R. 1949. History of the great fishery of Newfoundland. Time delays, density dependence, and single species oscillations. Gallimard, France. (Transl. from French by C.C. Taylor. U.S. Fish J. Anim. Ecol. 43: 747-770. WildB. Serv. Spec. Sci. Rep. (Fish.) No. 213, 1957). MESSTORFF,J. 1984. Research vessel survey results for cod in division 25 DEYOUNG,B., AND G.A. RQISE.1993. On recruitment and distribution of as obtained by WV Anton Dohrn and RV Walther Herwig in autumn Atlantic cod (Gadus morhua) off Newfoundland. Can. J. Fish. Aquat. 1972-83. NAFO Sci. Counc. Res. Doc. 84/VI/91, Ser. No. N882: 7 p. Sci. 50: 2729 -2741. MILLAR,R.B., AND R.A. ~~YERS.1990. Modelling environmentally induced DRINKWATER,K.F. 1994. Overview of environmental conditions in the change in growth for Atlantic Canada cod stocks. Int. Counc. Explor. Northwest Atlantic in 1993. DFO Atl. Fish. Res. Doc. 9411 1. Sea C.M. 1990/G:24: 13 p. FINLAYSON,A.C. 1994. Fishing for truth: a sociological analysis of northern MOWN,R.K., AND R. COOK.1993. Introduction to sequential population cod assessments from 1977-1990. Inst. Soc. Econ. Res., Memorial analysis. NAFO Sci. Counc. Stud. No. 17, Dartmouth, N.S. 1 18 p. University of Newfoundland, St. John's, Nfld. 176 p. MYERS,R.A., K. DRINKWATER,AND N. BARROWMAN.1992. Cold water and FLEMING,A.M. 1952. A study sf the age and growth of the cod (Gadus recruitment in 2J3KL cod. CAFSAC Res. Doc. 92197: 13 p. callarias L.) in the Newfoundland area. M.A. thesis, University of MYERS,R.A., AND N.G. CADIGAN.1993. Density-dependent juvenile mor- Toronto, Toronto, Ont. 1 19 p. tality in marine demersal fish. Can. J. Fish. Aquat. Sci. 58: 1576-1590. FRCC. 1993. Report on the status of groundfish stocks in the Canadian MYERS,R.A., AND N.G. CADIGAN.1995. Was an increase in natural nnodity Northwest Atlantic. Fisheries Resource Conservation Council. Bepart- responsible for the collapse of northern cod? Can. J. Fish. Aquat. Sci. ment of Fisheries and Oceans, Ottawa, Ont. 52. (In press) GAVARIS,S. 1988. An adaptive framework for the estimation of popula- MYERS,R.A., K.F. DRINKWATER,N.J. BARWOWMAN,AND J.W. BAIRD.1993. tion size. CAFSAC Res. Doc. 88/29: 12 p. Salinity and recruitment of Atlantic cod (Gadus morhua) in the GOSLING,W.G. 19 10. Labrador: its discovery, exploration, and develop- Newfoundland region. Can. J. Fish. Aquat. Sci. 50: 1599-1609. ment. Rivers, London. 574 p. NAFO. 1984-94. Fishery statistics for 1979-1990. Statistical Bulletins GULLAND,J.A. 1983. Fish stock assessment: a manual of basic methods. 29-40, Dartmouth, N.S. Wiley & Sons, New Yc~rk,N.Y. 223 p. NAFO. 1992. Report of the special meeting scientific council, 1-4 June GUE-LAND,J.A., AND L.K. BOEREMA.1973. Scientific advice on catch lev- 1992. NAFO Sci. Counc. Stud. Doc. 92/28, Ser. No. N2112: 39 p. els. Fish. Bull. 71: 325-335. NEIS, B. 1992. Fishers' ecological knowledge and stock assessment in HARRIS,L. 1990. Independent review of the state of the northern cod stock. Newfoundland. Nfld. Stud. 8: 155-178. Communications Directorate, Department of Fisheries and Oceans, NEWELL,J.P. 1991. Spring and summer ice and climate conditions in the Ottawa, Ont. 154 p. Labrador Sea, 1800-present. Ph.B. thesis, University of Colorado, HARRISON,G.W. 2979. Stability under environmental stress: resistance, Boulder, Colo. Univ. Microfilm Inc., Ann Arbor, Mich., Order No. resilience, persistence, and variability. Am. Nat. 113: 659-669. 9122631. HARWOOD,J. 1978. The effect of management policies on the stability and NEWELL.9.P. 1992. Climate change in northeast Canada and the northwest resilience of British grey seal populations. J. Appl. Ecol. 15: 41 3-421. Atlantic: new insights from a long term sea ice data set, p. 87-90. Pn HASTIE,T.J., AND R.J. TIBSHIRANI.1990. Generalized additive modeis. ROC.5th Int. Meet. Statistical Climatology, Toronto Environment Chapman & Hall, New York, N.Y. 335 p. Canada, Atmospheric Environment Service, Toronto, Ont. HEAD,C.G. 1976. Eighteenth century Newfoundland. Macmillan & Stewart, NEWELL,J.P. 1993. Exceptionaliy large icebergs and ice islands in eastern Toronto, Ont. Canadian waters: a review of sightings from 1900 to present. Arctic 46: HBLBORN,R., AND C.J. WALTERS.1992. Quantitative fisheries stock assess- 205-21 1. ment. Chapman & Hall, New Ysrk, N.Y. 570 p. PETRIE,B., J.W. EODER,J. LAZIER,AND S.A. AKENHEAD.1992. Temperature HOL~,ING,C.S. 1973. Resilience and stability of ecological systems. Ann. Rev. and salinity variability on the eastern Newfoundland shelf: the residual Eco~.Syst. 4: 1-24. . field. Atmos. Ocean: 30: 120-139. HUTCHINGS.J.A. 1993. Adaptive life histories effected by age-specific sur- PIMM,S.L. 1991. The balance of nature?: ecological issues in the conser- vival and growth rate. Ecology 74: 673-684. vation of species and comnmunities. University of Chicago Press, HUTCHINGS,J.A., AND R.A. MYERS.1993. The effect, of age on the sea- Chicago, Ill. 434 p. sonality of maturation and spawning of Atlantic cod, Gadus morhua, RADOVHTCH,J. 1981. Lessons from coastal upwelling fisheries, p. 107-136. in the Northwest Atlantic. Can. J. Fish. Aquat. Sci. 58: 2468-2474. Pn M.R. Glantz and J.D. Thompson [ed.] Resource management and HUTCHINGS,J.A., AND R.A. MYERS.1994. The timing of cod reproduction: environmental uncertainty. Wiley & Sons, New York, N.Y. interannual variability and the influence of temperature. Mar. Ecol. RICHARDS,L.J., AND J.T. SCHNUTE.1986. An experimental and statistical Prog. Ser. 108: 21-3 1. approach to the question: is CPUE an index of abundance? Can. H~~TCWIPIGS,J.A., AND R.A. MYERS.1995. The biological collapse of Atlantic J. Fish. Aquat. Sci. 43: 1214-1227. cod off Newfoundland and Labrador: an exploration of historical ROFF, D.A. 1992. The evolution of life histories: theory and analysis. changes in exploitation, harvesting technology, and management. P~E Chapman & Hall, New York, N.Y. 535 p. R. Arnason and L. Felt bed.] Island fisheries of the North Atlantic. ROSE,G.A., AND W.C. LEG GET^. 1991. Effects of biomass-range interactions University of Malta Press, Malta. (In press) on catchability of migratory demersal fish by mobile fisheries: an ICNAF. 1952. Statistics of landings of groundfish from the convention area. example of Atlantic cod (Gadus morhua). Can. J. Fish. Aquat. Sci. Second annual report for the year 1951-52. ICNAF, St. Andrews, N.B. 48: 843-848. JACOBY,G.C., AND E.R. COOK.1983. Past temperature variations inferred ROSENBERG,A.A., M.J. FOGARTY,M.P. SISSENWINE,J.R., BEDDINGTON, from a 400-year tree-ring chronology from Yukon Territory, Canada. AND J.G. SHEPHERD.1993. Achieving sustainable use of renewable Arct. Alp. Res. 13: 409-418. resources. Science (Wash., D.C.) 262: 828 -829. KIRBY,M.J.L. 1982. Navigating troubled waters. A new policy for the ROTHSCHILD,B.J. 1977. Fishing effort, p. 97-1 15. Pn J.A. Gulland [ed.]

Con. J. Fish. Aq~ecat.Sci., VoE. 51, I994 Fish population dynamics. Wiley B Sons, New York, N.Y. SUTCLIFFE,W.H., R.H. LOUCKS,K.F. DRINK~ATER,AND A.R. COOTE.1983. SCHAPWR,W.M. 1974. Selection for optimal life histories: the effects of age Nutrient flux onto the Labrador Shelf from Hudson Strait and its bio- structure. Ecology 55: 291-303. logical consequences. Can. J. Fish. Aquat. Sci. 40: 1692-1701. SHELTON,P.A., AND M.J. MORGAN.1993. An analysis of NAFB Division TEMPLEMAN,W. 1965. Mass mortalities of marine fishes in the Newfoundland 2J3KL cod spawner biomass and recruitment. NAHO Sci. Cesunc. area presumably due to low temperature. ICNAF Spec. Publ. No. 6: Res/Boc. 93/37, Ser. No. N2217: 14 p. 137-147. SINGLAIR,P.R. 1985. Prom traps to draggers: domestic commodity pro- TEMPLEMAN,W. 1966. Marine resources of Newfoundland. Bull. Fish. Res. duction in northwest Newfoundland, 1850-1982. Inst. Soc. Econ. Res., Board Can. 154: 1'70 p. Memorial University sf Newfoundland, St. John's, Nfld. 171 p. WARNER,W.W. 197'7. Distant water: the fate of North Atlantic fishermen. STEARNS,S.C. 1992. The evolution of life histories. Oxford University Little, Brown & Cs., Boston, Mass. 338 p. Press, Oxford. 249 p. STEELE,D.H., R. ANDERSEN,AND J.M. GREEN.1992. The managed som- mercial annihilation of northern cod. Nfld. Stud. 8: 34-68.