A restrospective view

The motive for this summary

Although I am long retired from a paid job, this exercise in retrospection gives me time to reflect on my past career as a fisheries scientist. My latest work, a review of the history of scallop research in Canada, put me in the unusual frame of mind to look backwards in time. Autobiographies are unconventional for scientists, and this is only the professional side of my life, and written mainly for my own satisfaction. I was born in Ulverston, Cumbria, and moved to Croydon where my father was postmaster and my mother a school teacher. After the usual educational sequence, I arrived at a doctorate in Marine Ecology granted by Queen Mary College of the University of London, and shortly after, took up a position in the Canadian Fisheries Research Board, where my training as a fishery biologist took place. I then had the further good fortune to be hired by FAO in 1979, and retired from FAO in 1999. I have reported my experiences in fisheries biology, population dynamics and fish stock assessment in some 90+ primary publications and books on fishery-related issues spelled out below. During my period at the FAO I became involved in international policy issues, designed national fishery research programs, and drafted government fishery management plans and cooperative projects, and a variety of related issues which have continued into an active retirement.

The fact that I have resisted being a specialist, which is a result often forced on career scientists, is a positive aspect that merits recording. Maintaining research activity in several fields, largely unplanned, was perhaps the main theme of my scientific approach. I note here that in 2012 I finally published the ‘missing’ paper from my PhD Thesis 45 years after I had concluded my molluscan research in the Thames Estuary. Subconsciously perhaps, I saw this as evidence I have completed my lifetime ‘post thesis’ efforts, and in theory, can retire now after a final report, given that this long-overdue paper is now in press!

My career began with attention to problems of shellfish research, which was given impetus by two summers as a student assistant at the Burnham-on-Crouch shellfish laboratory in Essex. Here I assisted Donald Hancock and Duncan Waugh in their investigations on the cockle and oyster fisheries. Later, it was on one of my visits to Burnham laboratory that I saw an advert for a position of a shellfish biologist with the Fisheries Research Board of Canada laboratory at St Andrews NB. I applied for the post and was accepted.

Research on marine invertebrates

My first Canadian research focus was on invertebrate fisheries, particularly for the scallop, Placopecten magellanicus. Most of the outputs from this have been described in a recent historical review. While there were several scientific highlights to this scallop research, while working within a government research structure oriented to management of specific resources, it was difficult to extend my work to other subjects although I did specialize early on in the use of submersible vehicles for survey work. However, my scallop research was confined as mainly relevant to other molluscan researchers. An early career emphasis on management of marine invertebrate fisheries was summarized in the 1989 book I edited for John Wiley. Changes began after my sabbatical year at the University of Washington in 1973-4 where I picked up some elements of population dynamics and modeling. This effectively concluded a period when active research in the field was the key theme.

On returning to St Andrews in 1974 after my sabbatical year, I was responsible for research on invertebrate fisheries in the Canadian Maritimes. One focus was on a re-evaluation of simple yield models for important species such as lobsters, where molting divides a cohort into size specific categories, and where molt frequency slows dramatically with age. The influence of molting (an instantaneous increase in size) on yield-per-recruit was investigated, together with the impact of progressively longer intermolt periods. This was shown to be effectively equivalent to a decline in the high natural mortality rate of the juveniles with age.

After 10 years of work on offshore shellfish problems with a focus on underwater methodologies (scuba and submersibles), following my sabbatical year studying population dynamics at the University of Washington, Seattle, I spent two years researching large pelagic (swordfish and bluefin tuna) populations and became the scientific reporter for Canada at ICCAT. In 1973, with Mike Butler, we demonstrated the results of our bluefin otolith studies: these were sectioned with a then new diamond saw. We showed that large bluefin are much older than previously reported from fin ray sections – a result which should have led to specific management results for a seriously overexploited species. The following year I reported the first Atlantic bluefin VPA, based on data from the international fisheries for Atlantic and Mediterranean bluefin. This led to a push for a minimum size limit for a tuna species to be introduced by ICCAT, although the high exploitation rate for the adults still continues, with the fishery in part feeding catches into mariculture. The ICCAT exercise (carried out under great pressure) was noted by the then Canadian representative at ICCAT, Ken Lucas, who proposed me for a vacant post at FAO. Once there, I became concerned with fisheries management on a global scale under John Gulland, then Chief of the Marine Resources Service.

Work at FAO

It is worth noting that my career as a fisheries biologist led me to study different species and ecosystems in many parts of the world. It meant that I had to tackle a wide variety of problems at FAO. Whatever the problem, I had to make an effort to rapidly access historical and biological information of relevance. Most of the reports listed below were achieved with the kind cooperation of scientists who were better versed in mathematical theory and computer programming than I was, and often with more local experience. It is also noteworthy that new approaches to the same problem after a decade or so, tended to recur to me in a different context, confirming the value of long experience.

The 1970’s-80’s was a period when fisheries theory was mainly based on age-structured models leading to Virtual Population Analyses, or to Production Modeling where no knowledge of age or size structure was required. Together with research vessel survey results, these were the key methodologies used by most Fisheries Commissions in arriving at species, country or fleet quotas. They required, on the one hand, statistically valid data on age or size frequency of catches and an age length key for ‘analytical analyses’ (for those using age compositions of catches as a measure of mortality due to fishing). On the other hand, information on effective fleet size, fishing power and fishing effort exerted, were also required for measuring the pressure exerted on the stocks when using production models. Attempts with colleagues (J. Csirke and O. Defeo) to combine aspects of the two methodologies by replacing fishing effort by total mortality rates, allowed an assessment of the state of exploitation of the stock where fishing effort was missing – thus avoiding the need to consider changes in fishing power by measuring total mortality directly, giving a provisional estimate of the natural mortality rate. What was evident for production modeling however, (see book by R. Hilborn and C. Walters), was that methodologies assuming that fisheries data could be adjusted for ‘departures from equilibrium’ as suggested by John Gulland, may give misleading results.

In the 1970’s there was pressure to move in the direction of size frequency analysis, and this often resulted in a neglect of measurements of fleet size and fishing effort (largely the responsibility of the government agency concerned). Most governments had few qualified fisheries workers, nor had they reliable data on either national fleet performance, and even less on the performance of distant water vessels exploiting national and distant water resources. Size frequency analysis was picked up by non-government organizations as a more attractive and easier approach than the conventional one, allowing developing country scientists to make original contributions even without government statistics on fleet performance, even though this work was often uncertain in its implications for future effort and quotas. The main problem with a purely size-based approach is that the simple packaged software then available gave statistically unreliable results, and the values obtained for population parameters are often biased, and not easily translated into management advice relevant to fishing fleets.

After the Law of the Sea

The Law of the Sea was an important first step for international fisheries management. Following this came UNCED, where FAO was required to draft a background document outlining the issues facing marine fisheries. I prepared this as an FAO Technical paper, expanding on the questions involved, but subsequent management measures followed slowly however. Bringing this issue home to coastal countries was later the task of the FAO initiative, the Mexican-sponsored ‘Code of Conduct for Responsible Fisheries’ which measured implementation of a Code based on broad experience with fishery management, and I played a significant role in negotiation of the issues underlying Article 7 on the Guidelines for Fisheries Management. Action to implement the Code was voluntary for participating countries, and although many countries had accepted the Code in principle, criteria used to judge implementation were not fully understood or laid out. Hence the preparation of a series of technical guidelines for elements of the Code was necessary, and was initiated within the fisheries department of FAO. Implementation has been slow in some cases, and depends to a large extent on whether countries have the technical, financial and trained manpower resources to comply. One of the possible methodologies I promoted was the use of formal questionnaires, which when filled in by industry or government representatives, provides a way of judging implementation.

The UN Fish Stock Agreement

Almost contemporaneously with meetings on the Code, came a second initiative, this time by the UN, in an attempt to introduce more stringent management measures for offshore fisheries. This initially adopted the classical management target already built into the Law of the Sea, known as ‘The Maximum Sustainable Yield (MSY)’. The assumption was that aiming for a maximum yield from a fishery would be a safe procedure, but by the time of the so-called ‘UN Fish Stock Agreement’, targeting this reference point as a safe procedure had begun to be questioned since effort overshoots were frequent. Almost inevitably, the fishing effort corresponding to MSY (i.e., f_MSY), was overshot in the management process, and a painful period of reduction in quotas was then needed to restore MSY conditions. The UN Fish Stock Agreement required more stringent measures to reduce total fishing effort, and was hard to achieve, particularly when more than one national fleet was involved. One approach included in the background paper I prepared for the UN meeting (later published, with some modifications, as an FAO technical report with R. Mahon), was the concept of a Limit Reference Point (LRP). This set a lower fishing mortality rate than f_MSY, or a higher biomass than B_MSY, as desired targets. Another approach was to integrate MSY and LRP criteria into a statistical procedure. This procedure was published later with R. McGarvey, and later was updated cooperatively with M. Prager and colleagues.

A role in relation to Fishery Commissions

In Canada and at FAO, I was occupied with both research and policy development, especially in backstopping the work of Fisheries Commissions, developing research projects and proposals and project evaluation. With respect to independent fishery commissions, I attended NAFO, IATTC, and ICCAT, and for 15 years was the technical secretary of the General Fisheries Commission for the Mediterranean and the Western Central Atlantic Fisheries Commission. I played a role also in Black Seas fishery management bodies, in the Gulfs Committee of the Indian Ocean Fishery Commission, and later reviewed all Commission activities in fish stock assessment elsewhere, as Service Chief of FIRM, which was then FAO’s service dedicated to resource management of marine resources.

One area of emphasis was on fisheries negotiations, both federal-provincial when in Canada, and on international boundary issues. With respect to shared stocks, in the 1970’s I was part of the Canadian team involved in maritime boundary negotiations with the US over Georges Bank resources. Prior to that, after 8 years of responsibility for scallop research, I was well known to both Canadian and US scallop industries for my knowledge of the Georges Bank resources. (The majority of Canadian research work actually carried out on the Bank in support of the national claim to the Northeast side of the Bank, came from the invertebrate fisheries carried out there). More recently I have advised on shared stock issues for the Lesser Antilles countries, the Government of Malta, and Mediterranean and Black Sea countries. I later presented a broad review of shared stock issues at a conference in Australia.

Environmental Issues

In FAO I was given a role in a number of important global initiatives on environmental issues, and drafted and backstopped fishery-related projects funded by UNDP and other agencies. Much of my experience was in practical applications of population dynamics, but I used empirical information where conventional data sources were inadequate. With respect to the environment, a technical document on marine living resources was prepared for the UNCED process in negotiating Agenda 21 for the Oceans. An environmental emphasis of this work reviewed the effects of nutrient runoff on fisheries of coastal and inland seas. This focus on the dominant processes governing fishery productivity and coastal eutrophication was continued in papers issued in cooperation with the oceanographer, Andrew Bakun. On the issue of marine resource negotiations, a handbook specifying appropriate criteria for distant water vessels fishing shared stocks in national waters of developing countries was co-authored and published by the US WWF.

Action Plans were developed for the Black Sea and Mediterranean environments, and management proposals and modeling approaches were put forward for the Black Sea in cooperation with Russian colleagues for the Black Sea pelagic ecosystem. One model with W. Christensen simulated the effects of the Mnemiopsis (jellyfish) invasion on the fisheries of that inland sea.

In 2001-2 I was advisor to CITES and associated NGO’s on the conservation of sturgeon stocks of the Danube/Black Sea. Working with Black Sea experts, a preliminary migration model for river Danube sturgeon management was proposed (but not accepted), and a suggestion made for a new reporting scheme to reduce illegal fishing and marketing.

Ecosystem issues

Published papers have reviewed the apparent changes in trophic composition of world marine harvests, and these showed that not only top-down effects of fisheries are responsible. In particular, Atlantic fisheries have been subject to drastic overharvesting at different trophic levels where top down interactions could not have been the sole hypothesis responsible. In fact gross overfishing and changes in environmental conditions affecting stock productivity were relevant on both sides of the Atlantic and elsewhere.

In 1996, the actual first 'Peter Larkin Memorial Lecture' presented was entitled: "Fisheries management in the 21st Century: will new paradigms apply?", and was published in Reviews in Fisheries Science, to be supplanted in the first place by a posthumous review of the fisheries research by Ray Beverton, the internationally recognized ‘father’ of post-war fisheries research. My paper spelled out several likely scenarios for world fisheries development in the near future. Other papers presented on a similar theme were: ‘Applications of ecology to sustainable fisheries management: problems and perspectives’ to the British Ecological Society, in the Royal Society London, 14-Feb 2000, and with Kevern Cochrane, we provided a review of fisheries management past and present, and speculated on future perspectives for fisheries in the third millennium. A review of global experience and strategies for rebuilding overexploited marine fish stocks was prepared for the Irish Government, and in September 2003 was given as a keynote invited lecture at ICES and later published.

Fisheries of semi-enclosed seas

The particular fisheries of the Mediterranean Sea require an approach to fishery management that differs from the classical Beverton and Holt approach used in the North Atlantic. It has taken a decade or more of emphasis and a number of presentations and publications, before this new approach seems accepted for demersal fisheries in the Mediterranean, and there is even evidence that some of its implications are being taken into account in North Atlantic fishery management. The two issues that are of key importance in managing demersal trawl fisheries, are that a continued reliance on mesh size regulations would lead to heavy discards. The existence of markets where small whole fishes have been consumed for generations, provide fishers with high prices per kilo, and fishery biologists have a more concrete motive for exploring models for managing fisheries on juveniles. This should also be taken into account in bioeconomic calculations. The emphasis on small fish capture also affects assessment theory: recent research illustrates the fallacy that a larger mesh size effectively protects escapees. Due to a higher rate of predation on juveniles than adults, they must be assessed at a higher (and rapidly declining) natural mortality rate with size. Conserving the larger mature fish for a self-sustaining population is emphasized as of high importance in a fishery aimed at juveniles, with escapees often partially protected by refugia. In the Mediterranean; this refugia strategy is assisted by the extensive rocky bottom areas found on most narrow Mediterranean shelves. These offer some protection from trawlers – leading to the suggestion that refugia exist where spawners receive some protection, but harvests of juveniles, while they need to be controlled, cannot be readily abandoned.