Fishing about and about fishing
Approved as a chapter in the book of the Bulg.Ac.of Sc.
12-03-2014
CHALLENGING SCIENTIFIC INERTIA IN FISHERIES MANAGEMENT
ABSTRACT
This chapter critically reviews the inertia prevailing in the western fisheries management system, which embraces such assumptions as equilibrium in fishery ecosystems, large spawning stocks producing large new generations; fishing is the main or only factor that affects the targeted stock size and, therefore, external environmental and social factors can be disregarded; management by output is a panacea in all sorts of fishing systems; selectivity by size is a must, and more. It criticizes the use for stock assessment of highly inadequate mathematical models and setting of allowable catch quotas, which are based on flawed science. This system is for tens of years willy-nilly supported by scientists depending on governmental and institutional employment, in spite of abundance of books, studies and research papers published by independent researchers attempting to set straight the official fishery science and the consequent management.
KEY WORDS
Ecosystem, Environmental fluctuations, Fishery management, Marine ecology, Mathematical models, Population dynamics.
Baranov, Ben-Yami, Beverton, Hilborn, Klyashtorin, Kolding, Rothschild, Sharp, Zadeh.
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CHALLENGING SCIENTIFIC INERTIA IN FISHERIES MANAGEMENT
Menakhem Ben-Yami
INTRODUCTION
The adequacy of the science and the consequent management prevailing in the Western World fisheries and its validity for the developing countries' fisheries is questioned. Population dynamics supported by mathematical/statistical models, and acoustic surveys, along with mainly single-species stocks assessment are inherently dependent on good real-time field data. But, even where available, those are the misleading equilibrium assumptions that have become the official science and basis for fisheries management, which considers natural mortality constant and fishing the almost sole cause for stock size fluctuations. Such management only too often doesn't pay sufficient attention to the human factor, in spite that humans are the only thing it can manage, and disregards most if not all environmental, abiotic and biotic, natural and anthropogenic, factors that do affect fluctuations in fish populations. Generations of western fisheries scientists have been trained within this paradigm to which they stick due to mental and institutional inertia. But, since fisheries present a dynamic process where fish, fishermen, and ever-changing environment interact, no wonder that the western fisheries management is deficient. In addition, canonical assumptions, such as: the larger is the spawning stock the larger the recruitment; single-species catch management is the remedy; models can be valid without input of environmental factors; fishing must be size-selective – are questioned.
For over a century, scientists independent of institutional pressure and inertia and realizing real-world fisheries ecology have been publishing scientific reports, papers and even books trying to set the course straight, but so far with little success. Thus, most fishery-management scientists are spending most of their time in operating and discussing computer models, while trying to circumvent insufficient information and data flaws by manipulating the models with mathematical/statistical exercises. Unfortunately, this practice comes at the expense of on-board research, sampling and data collection and analysis, and keeps scientists away from seas and fish, and from fishermen and their knowledge.
One purpose of this chapter is to warn the marine scientists and fisheries managers, who got their schooling or scholarships in fisheries science and management in Western European and North American countries. Some of them might've been coming from southern and eastern countries, where native science either hasn't yet developed locally, or has developed with different, often traditional approach. Notwithstanding, they would be very impressed with the modelling methodology and other paradigms, as well as with output-management system they were taught at the various Western fisheries institution. Coming back home they'd quite naturally be inclined to introduce in their national or local fisheries the knowledge they had acquired, lock, stock and barrel. They should, however, to be very judicious about some of the western paradigms they've been taught. Not only that uncritical copying of the Western official fisheries science and management methodology is a bad thing to do, but also that often those are wrong even for the West's own fisheries.
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1 – On scientists associated with the official management of fisheries
Scientists employed by governments depend personally and institutionally on their administration's political and economical interests. Fisheries management worldwide has become a business in its own right that has a vested interest in expansion and perpetuation of its own bureaucratic system supposed to prevent the oceans from being stripped bare. While it cannot directly manage fish stocks or their environment, all it can do is to manage people. Quick to blame fishermen for overfishing, the management is not prepared to take the blame for its own wrong decisions that harm resources, fishing people and their industry, and the environment.
Managers insist on clear-cut scientific advice, set in precise figures. Their scientists in turn use whatever available data and information and feed them into various mathematical models unable to represent the fisheries ecosystem and its dynamics in real time. What they produce are the ridiculously exact figures of the size of fish stocks and allowable catches that at best are highly approximate and at worst - worthless.
William Ward and Priscilla Weeks (1994), placed under the anthropologist's magnifying glass, a group of fishery science & management workers. They found that much of those workers’ approach was made up of concepts and presumptions inherited from the old hands in the system, and that fishery scientists were not being taught to deal with people’s social, cultural and economic problems. They promulgate, therefore, more of the same, scorning other concepts and ideas. They tend to extrapolate rather from established models and theories than from actual research findings, and ignore fishermen’s knowledge. They have been taught to employ statistical models and aged monitoring programs, to consider themselves stewards of the resource, and to believe in the "tragedy of commons". Moreover, much of their approach is made up of concepts and presumptions inherited from the system. Their practice of self-sampling reduces contact with the fishing industry and people. Their own knowledge and understanding of the fishery-ecosystem dynamics is limited, and their perceptions almost petrified. While Wards’ and Weeks’ analysis over-generalises when it comes to individual scientists, on the whole it reflects the ”system” (Ward & Weeks, loc cit).
Also R.T. Lackey, of the American Environmental Protection Agency (USEPA), a respected scientist not associated with the official fisheries science and management, addressed this problem: “Much of the available science is tendered by government agencies, commercial interests, public and private organizations, as well as public and private interests and advocacy groups. Each arguably has a vested interest in the outcome of the debate and often promulgates “science” that supports its favoured position” (Ben-Yami, 2006). All this has created a complex "ecosystem" of human interdependencies.
G.A .Rose (1997) wrote in Reviews in Fish Biology and Fisheries: …"for the last part of the 20th century" many new fisheries scientists were trained as statisticians rather than as biologists… They "knew numbers – not fish”. But those fisheries scientists have been advising the regulators and managers on legislation and regulations, national and area-specific fishing rules, total allowable yields, quotas, and fishing effort. The managers, personally and institutionally co-operating with and often quite depended on politicians, are using their fisheries scientists' and economists' advice to cover their tail, whenever their decisions may be unpopular "upstairs" or "downstairs". The advice from economists is not a problem. They always would advise according to their political-economical persuasion (because economics, even if it uses scientific methods, is
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not a science), while the managers choose advisers convenient to those in power, (Rose, loc cit). Prof. Ray Hilborn of the School of Aquatic and Fisheries Sciences, University of Washington, has long been complaining of "Faith Based Fisheries", and the deviation of some scientists and such respected scientific journals, as Nature and Science from honest scientific approach. He thinks that "within our own field" a strong movement of faith-based acceptance of ideas has emerged in the last decades of the 20th century. Scientists search for data that support these ideas without critically analyzing evidence. This movement of faith-based fisheries threatens the very heart of the scientific process — peer review and publication in the above highest profile journals. But, Prof. Hilborn wrote: "the peer review process has now totally failed and many of these papers are being published only because the editors and selected reviewers believe in the message, or because of their potential newsworthiness" (Hilborn, 2006).
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2 – On fishery ecosystems
The dynamic mechanism of processes and inter-relations occurring in fishery ecosystems have been not yet adequately studied and explained and, hence, often disregarded in fisheries management approaches. We still need a better understanding of how the marine ecosystem functions under the effects of atmospheric and marine climates, and major anthropogenic habitats modifications.
SEMANTICS: The meaning of terms like "ecology" and "ecosystem" is often blurred or vulgarized. Although, it may seem unnecessary to some of our readers, here are put forth a few definitions to make it clear what this chapter is writing about.
ECOLOGY: It is seen as the "economics of Nature", for it deals with energy and matter exchange as economics deal with goods, work, and capital exchange. However, while economic units of exchange are relatively few and of known value, and so are most of the participating factors and most of the rules, the business of exchange that's going on within every ecosystem is much more complex, less known, the rules and inter-relations between the various "clients" and their surroundings less defined, and units of exchange numerous, their values changing all the time.
Both, economics and ecology aren't exact sciences. The human nature and free-will that are not following the "rational choice" paradigm spoil the reliability of economic models, while the mostly unpredictable climatic fluctuations and environmental changes, as well as human interventions upset the credibility of the precise results obtained by the various elegant population dynamics models.
FISHERY ECOLOGY: It studies, analyses, and describes FISHERY ECOSYSTEMS. Its prediction attempts and forecasting models have been even less successful than parallel attempts in economics, and rather miserable at protection and management of aquatic basins and their resources. FISHERY ECOLOGY is as much about fishing people and climatic vagaries, as it is about fish and their prey, predators and habitat, where fisheries take place.
ECOSYSTEM: is a space in which numerous processes occur simultaneously, interact, and influence each other. External ever-changing factors and internal fluctuations cause ecosystems to subsist in a dynamic, often spasmodic disequilibrium.
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A FISHERY ECOSYSTEM is an aquatic ecosystem in which fish and fishing people encounter each other as, respectively, prey and predators. An ecosystem in which fishing people are not playing a significant role is not a fishery ecosystem. Understanding the mechanisms of fishery ecosystems requires integration of information on their oceanographic and biological features and their effect on fish yields, abundance and availability, on fishermen's behaviour, culture, technology, market performance and its effect on prices, hence on fishing effort. It also requires research into life history and population dynamics of the main species fished and into the effect of human intervention by inshore changes, discharging nutrients and various poisonous substances.
According to the World Ocean Review 2013, (http://worldoceanreview.com/en/), to become workable, and realistic, the ecosystem approach to fisheries must involve groups of exploited species, rather than separate single stocks. Quantified assessments, such as TAC (total allowable catch) and MSY (maximum sustainable yield) would make more sense and approach biological realities, when set forth as a range of values rather than in ridiculously precise figures (see below: Fuzzy logic). Predators, such as marine mammals, birds and predatory fish interact with commercial fishes, plankton and smaller fish species in various ways. Also the relationships between all species occupying the ecosystem at all stages of their life must be considered, along with ecological interaction such as corals that form habitats for fish. Ecosystem approach must consider the dynamics of the marine environment, in space, time and character, including the food web and associated trophic interactions (Caddy and Sharp, 1986). Historical climatic and oceanographic trends and fluctuations that have been occurring in the ecosystem must be taken into account, as well as all the physical, biological and chemical forces imposed upon habitats by human activities
The ecosystem approach must be concerned with all stakeholders, their performance and activities. FAO outlined the ecosystem approach, as follows: "An ecosystem approach to fisheries strives to balance diverse societal objectives, by taking into account the knowledge and uncertainties about biotic, abiotic and human components of ecosystems and their interactions, and applying an integrated approach to fisheries within ecologically meaningful boundaries." (Bianchi, 2008).
Apart from management of fishing, ecosystem approach must deal also with protection of habitat from unreasonable development, coastal and upstream pollution, extraction of various sea-bottom components and of oil, shipping and other traffic, etc. For example, enclosed seas such as the Baltic, the Mediterranean and the Black and Azov Seas have been in various states of enrichment due to influx of urban, agricultural, and industrial wastes (Ben-Yami, 1994). See more at: http://www.worldfishing.net/news101/Comment/ben-yami/new-name,-new-game.
Our competitors. In most fishery ecosystems marine mammals and sea birds are fishermen's major competitors, and are assessed to consume at least as many fish as humans (Beverton, 1994), while according to later data, even up to 10 or more times the amount of protein extracted from the seas by fishing (Ben-Yami, 2008; Brooke, M. de L., 2004).
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Table 1 (Stolpe, 2008) gives consumption by piscevore marine mammals in Northwest Atlantic Ocean, demonstrating its ovewhelming share in the natural mortality of fishes.
Here Table 1
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In many cases of over-exploitation or collapse of aquatic ecosystems in the recent century, fishery hasn't been the sole or even principal culprit. Urbanization, population growth, intensification of
agriculture, forests exploitation, and associated nurturing of sea-polluting industries whose true societal costs to operate have not yet been calculated or paid, are the principal causes of diverting much of the ecosystem production into eutrophication, and also of the depletion of fish and other marine animals.
Collapses. One of the worst examples of ecosystem collapses, which had little to do with fishing, happened in the Black Sea and the highly productive, adjacent fish-rich Azov Sea, which in the 1930s was producing fish yields of close to 100 kg/ha/year. An anthropogenic gradual environmental degradation of the Azov Sea was followed by eutrophication, phytoplankton and the consequent medusae blooms. In the 1980s, a ctenophore comb-jelly was incidentally introduced in the Black Sea. This, during less than one decade, had all but destroyed productive, mainly pelagic fisheries. The comb-jelly developed within a few years a giant biomass of over three quarters of a billion tonnes, destroying plankton and the progeny of most fish species, and thus also its own support levels, converting the ecosystem into a top-heavy pyramid. In the meantime, the Black and Azov Seas landings capsized, with those of the USSR fishermen shrinking by US$23,000M and the Turkish anchovy fishery losing a quarter of a billion US$/year. Then, the comb-jelly population had shrunk drastically for lack of food, and the Black Sea system swung towards a new survival mode. (Ben-Yami, 1994; Popescu, 2010; Sharp,D.G., M.Ben-Yami and J.Russ McGoodwin, undated).
As we are looking at ecosystems we must remember that a static approach, however good and detailed is the picture it produces, is insufficient for understanding of their workings. Ecosystems wax and wane in response to seasonal and climatic pattern changes, in seasonal and multi-annual cycles. Sunlight, which influences air, water, and land surface temperatures, is the principal force behind primary production. Temperatures, in turn, change in response to day length, cloud cover, and influx of source waters, such as snow melt or rainfall, which shifts with seasonal and climatic variations. The velocity and relative moisture contents of surface winds also influence ecological patterns of production (Shuleikin, 1949: Sharp et al, undated).
Winds cause evaporation, local cooling and downward mixing of the cooled denser water. Winds blowing long and strong enough in offshore directions and driving away warmer surface water layer, combine with surface evaporation in causing coastal upwelling processes bringing nutrient-rich waters from the depth of the ocean. Wherever major upwelling prevails, as along western shores of the tropical Atlantic and Pacific Oceans, major fisheries develop. Where upwelling is seasonal so are the fisheries (loc cit; Pinsky, M. L., Worm, B., Fogarty, M.J. Sarmiento, J.L. & Levin S.A., 2013).
This dynamics is powered by an array of ecological processes and feedbacks, components of the complexity of production systems. Basic seasonal primary production, dispersion of the primary products, grazing, predation, predator migrations, eutrophication and sedimentation often leading to anoxia. All of this happens on either a single or multi-annual time scale. (Sharp et al, loc cit),
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The discussion about whether marine ecosystems are in equilibrium or rather in a dynamic and ever-fluctuating disequilibrium is as old as the science itself (Hjort 1914), nonetheless it gave birth to the "new ecology", which maintains that "local ecosystems in most cases must be considered to be in a constant and ever changing state of disequilibrium, density independent instability, and even chaotic fluctuations due to considerable climatic variation (e.g. in rainfall, temperature, wind and evaporation) or human interventions (habitat change, pollution, eutrophication)", (Kolding, 1992, 1997). All those variables are external to the system and manifestly associated with shifts in fish populations, which as they come so they go, notwithstanding the theory of ecosystem equilibrium (loc cit).
3 – Fisheries science and mathematical models
During the second half of the last century, fisheries science has become entrenched in a methodology based on mathematical/statistical models of population dynamics, supported by acoustic surveys. Practicing this methodology has become to many a scientist a comfortable alternative to sea-going research, in-situ and in-vitro studies. It has been focused at mainly single-species stocks assessments, with fishing treated as the almost sole cause for stock size fluctuations. A veteran fishery ecologist and physiological oceanographer, Dr. Gary Sharp (1995), wrote that "Ecosystem Modelling has become an academic field of general interest, based on inadequate empirical observations and data, which produces unreliable and unverified results, not of real utility. Most models don't reflect changes other than simplistic Top-Down Trophic Energy Transfers (see in: References/Internet Sources). Such models cannot reliably either explain past changes, or project potential future changes". All the more that in many cases natural factors have a greater influence on the long-term abundance of many fish species than fishing. Dr. Sharp wrote also: “The last half century of poorly applied 'equilibrium-based' theories, and collapse of most or all the important contextual variables into a single 'parameter' - often held constant - has resulted in the chaos that we see everywhere in stock assessments, management decisions, and resource collapses”, (loc cit).
Notwithstanding, official fisheries establishment has been promoting "science-based" quantitatively oriented management; it produces precise figures of stocks biomass, spawning stock biomass (SSB), total allowable catches (TAC), maximum sustainable yields (MSY), and group and individual tradable quotas (ITQ). Presumed to represent actual factors, these figures are created with the help of mathematical models that consist of equations of variables incorporating stock size and age composition. Unfortunately, those models don't represent the reality close enough to be of practical value in fisheries management. appropriate models must contain all the important variables that influence the outcome, those variables' values must be true enough and their sources reliable; they must be so constructed that those variables interrelate as they interrelate in nature – a tall order. Additionally, as Prof. Mikko Heino of the Bergen Institute of Marine Research wrote in the International Council for the Exploration of the Sea (ICES) Newsletter: "Models that consider fish stocks in isolation from their ecosystem have clearly had their day", (Heino, 2003). Thus, many processes and interdependences that are "hard to see" cannot be quantified leading to conclusions in which “faith plays an accordingly large part in fisheries science” (Larkin, 1978).
Honest to life fishery science must involve multi-disciplinary and inter-disciplinary system of experimental, sea-borne and in-vitro research and integrated reasoning. It should employ all available tools of which modelling is only one that by no means is "science" by itself. If a model is
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well designed, and the data are correct and sufficient, with all the missing variables only moderately influencing the results, it may be of use to mainly shed light on the past, rather than on the future. Fish population models are nevertheless employed, because they are the only tool available for numerical stock assessment. Called the "best available science", they're in fact "inadequate science". Therefore, apart from the simplest fishery ecosystems, particularly, in subtropical and tropical multi-species fisheries, fisheries science should critically regard quantitative stock assessments and, instead, invest its resources in ecological-biological studies of the specific characteristics of target species in each separate fishery and of their relative position in the ecosystem. Knowledge and application of fish biology, physiology, ecology, behaviour, and their inter-relations in the environment would enable protecting fish at the right time and place, and choose realistic input controls, fitting the species' life history and environmental dynamics.
Fishery science needs to enhance biological and oceanographic research at sea, on-going monitoring and analysis, and consider to what degree external conditions are favourable or not. It must investigate all possible correlations between those factors and fish populations. Fishery ecology should become an important if not the main topic of research. Already in 1914 Hjort concluded that, in the case of the few species he investigated, recruitment was highly variable and that this was the major cause of the fluctuation of fish stocks. While pointing out that variability of the strength of year-classes was the main cause of fluctuation of fish stocks, Hjort also indicated that these fluctuations were driven primarily by the conditions prevailing at the time at which the development of the early life history stages of fish were taking place (Hjort, 1914). Massive stomach and gut analysis of commercial fishes, concurrent with the habitual aging, length measuring and weighing is essential to understand competition and prey-predator relations.
A Russian fishing technologist, who was the father of the fishing technology as a scientific-engineering discipline, Prof.F.I.Baranov (1918), published also a concept of single-species fish-stock dynamics model in the form of a simple catch equation, which is probably the most used in all of fisheries modelling methodology (Quinn and Collie, 2005), or serves as a basis for further model development. Commonly referred to as the Baranov catch equation, it gives catch (in numbers) as a function of initial population abundance N0, fishing F, and natural mortality M:
where T is the time period and is usually left out (i.e. T=1 is assumed). It assumes that fishing and natural mortality occur simultaneously and thus "compete" with each other. F expresses the proportion of deaths that are caused by fishing (fishing mortality), and M the number of other deaths (natural mortality). In the USSR, Baranov's approach was rejected and criticized by famous Russian scientists, N. Knipovich and G.V.Nikolskii for his "departure from the ecological approach and disregard of the dynamics of the environment". Over 100 years the Russian fisheries science has been focusing on ecological conditions under which fish populations procreate, feed, migrate, and change their behaviour. In the Soviet era, this approach had been applied to directing fishing fleets to times and areas of best fishing opportunities (Ben-Yami, 2010).
Nevertheless, Baranov's model along with the bulk of other models that followed in his footsteps, dominate the prevailing approach presuming that the amount of fish in a stock (C) is those left from last year, minus those that were caught (F) and those that died from predation and other causes (M) (Kolding and v.Zwieten, 2011). Unfortunately, this approach habitually
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and wrongly assumes that F is the only significantly changeable factor and that fishing alone is the cause of stock size fluctuations. This leads to the assumption that a fishery can be managed by only controlling fishing. However, M, usually assumed constant at 0.18 to 0.20, a largely arbitrary figure set by a German scientist a century ago, in real life is highly dynamic and variable and urgently needs reviewing.
The various post-Baranov and post-Beverton & Holt models, however their sophistication, are mostly unable to involve climatic and hydrographical fluctuations and anomalies, although some species with narrow temperature preference limits may be critically affected by even short environmental events during spawning, hatching and larval stages. According to Caddy (1999) the fisheries management science "should incorporate ecosystem considerations, including environmental fluctuations and socio-economic factors. They should not assume that current production levels are independent of natural fluctuations and human impacts...".
Other questionable features of these models are that they isolate a stock from other species, ignoring their prey-predator-competitor inter-relations and often assume linearity in the relationship between fishing effort and fishing mortality.
4 - Fishery science and non-fishing factors
In spite of lip service to non-fishing factors, the prevailing approach is that mainly fishing determines fish abundance, which is wrong to various degrees in most instances. A plethora of non-quantifiable factors other than fishing and their various combinations, affect fish abundance. Fishery managers must keep this in mind while trying to understand the real-world dynamics of fishery resources, (Laevastu, 1993).
Here's an abbreviated list of such factors: Factors, as availability of food, variations in recruitment caused by climatic-oceanographic fluctuations, and above all, temperature and salinity; the climate-related variability of fish populations, now recognized to be the rule rather than the exception (Klyashtorin 2001, Klyashtorin and Lyubushin, 2008; Rouyer et al, 2014); diseases often resulting from overcrowding, especially where associated with food scarcity; changes in species composition due to exotic immigrants on one hand, and departure of native fishes, on the other; predation by marine birds and mammals; prey availability; loss of genetic variability; pollution and eutrophication by fertilisers seepage; coastal and estuarine habitat degradation including destruction of spawning and nursery areas; blockage of migration routes; diversion and drying of streams; seismic testing; oil slicks and the chemicals used to clean them; dumping industrial and agricultural waste and dredge-spoil, and also favourable physical and chemical conditions, essential for the survival of eggs and larvae occurring at the right time and area.
Predation. The consumption by piscevore marine mammals in Northwest Atlantic Ocean, (see: Table in On fishery ecosystems (above) (Stolpe, 2008 ) demonstrates its ovewhelming share in the total mortality of fishes, and supports the argument against the fallatious use of the customary natural mortality values (M = 0.18-0.20). E.g., the world’s marine birds may consume 70 million tonnes of food each year (Beverton, 1994). The global wild catch is around 80 million tonnes, so if we include predation by marine mammals (Kashner and Pauly, 2005), it’s clear that the fishing yields may only be between a third and a half of total mortality. This means that M could reach 0.50 to 0.66 – a very long way from the 0.18 figure that has been traditionally used.
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Climatic fluctuations. Apart from non-fishing anthropogenic factors, fluctuations in the size of fish populations are affected mainly by fishing and the climatic variations. Rouyer et al (loc cit) who analyzed time-series for 27 Northeast Atlantic fish stocks, found that the intensity of the effect of temperature on biomass were dependent on the geographical location: the southernmost and northernmost stocks of their study displayed stronger associations with temperature than the stocks located in between, and concluded that the former were more prone to combined fishing-environmental effects. "The interplay between geographic location, climate and exploitation plays a significant role in fish stock productivity, which is generally ignored during assessment, thus (negatively) affecting management procedures"
Their findings support Prof. Mikko Heino's (2003) rather belated statement: "Probably for as long as there have been scientists, there has been the recognition that part of the variability in the numbers of fish is the result of changes in their food supply. This is especially the case when fish are at the sensitive larval stage. Food supply is related in part to the physical environment in the sea — the variability in sunlight, winds, and currents…”.
L.B. Klyashtorin and A.A. Lyubushin's (2008) book, “Cyclic Climate Changes and Fish Productivity”, shows that multi-annual and multi-decadal 50-70 years fluctuations in fish yields have been documented for 400 years in Japan and for 1,000 years in the Skagerrak herring fishery. Such periodicity has occurred in over a dozen of important commercial marine fish populations. 1,500-years-old time series of environmental indicators suggested similar periodicity. Similar, quasi-regular fluctuations of some 60 years were observed in the Black Sea surface waters temperature (Eremeev et al, 2012).
Off California, for the last 1,600 years, sardine and anchovy have interchanged every 50 to 70 years. There’s significant coherency of climate and long-term stock dynamics of Atlantic-Scandinavian cod. Graphs in Klyashtorin and Lyubushin's book (2008) illustrate how past and present "overfishing/collapses" of stocks were in fact "bottoms" of historic fluctuations, correlating with climatic cycles, and vice versa (see Fig. 1).
Here Fig.1.
Comparative dynamics of the temperature along the Kola meridian and herring recruitment
(13-year smoothing)
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Similarly, climatic fluctuation correlate with Atlantic herring and Arcto-Norwegian cod stocks oscillations with time series of 85 years (loc cit).
A hundred years ago, the famous Norwegian oceanographer Johan Hjort wrote that hydrographical and biological conditions are affecting the recruitment, strength of fish year-classes and fluctuation of fisheries (Hjort, 1914). He strongly encouraged ecological investigations of the causes of numerical variations in fish populations. One may say that Hjort would've never supported an approach that'd focus on fishing as the only or dominant factor influencing such fluctuations. He wrote that to "determine the numerical value of the year classes can only attain its object when based upon a study of the fluctuations in the population of the sea, both fish and smaller organisms, and thus of the whole organic life existent in the ocean, (which) is therefore the soundest possible basis for marine research, whether with theoretical or practical ends in view. There is moreover, scarcely any other question which is so well calculated to focus the attention of men engaged upon different branches of science, as this must necessarily be the case where several investigators are at work on board the same vessel. The constantly increasing knowledge of the hydrographical and biological conditions upon which the numbers of the organisms, and especially of the fish, so greatly depend, will naturally be of the greatest importance", (loc cit).
It appears that only recently contemporary science started re-discovering the old wisdom. Janet Nye et al (2009) tested the hypothesis that recent oceanographic/climatic changes in the Northeast United States continental shelf ecosystem have caused a change in spatial distribution of marine fish. Populations of several species exhibited a poleward shift in their center of biomass, most with a simultaneous increase in depth, and a few with a concomitant expansion of their northern range. These dislocations are explained by large-scale temperature increase and changes in circulation, represented by the Atlantic Multi-decadal Oscillation, which are likely to persist as long as the temperature is not returning to the past, lower level. (loc cit). Their character depends on local and regional temperature variations, since marine fauna adheres to a "complex mosaic of local climate velocities," Pinsky et al, loc cit).
SSB and recruitment. Also the conventional "wisdom" that large SSB is producing large recruitment, and vice-versa, in some cases has been proved wrong, while in others is in need of unprejudiced revision. Jon Kristjansson (2003) demonstrated how the numbers of both cod and haddock spawners and their recruitment on the Faroese plateau during the 1961-2000 period had fluctuated in opposite phase: when SSB was increasing, recruitment was decreasing and vice-versa. (See Fig. 2&3).
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Here Fig. 2. Haddock SSB vs. recruitment, Faroese Plateau.
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Here, when the size of SSB is plotted against the respective recruitment, there's no understandable relationship, though beyond some maximum values of SSB the recruitment obviously decreases. When plotted on a time scale (see Fig. 3), the recruitment is highly variable, with SSB increases following strong year classes and anti-correlating with the recruitment (loc cit).
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--------------------------------------------------------------------------------------------------------------------------------Here Fig. 3. Anti-correlating fluctuations of Faroese haddock SSB vs. recruitment.
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Using three year running average to remove high frequency noise and subtracting nine year average to swing around a medium term average shows that recruitment and spawning stock oscillate in anti-phase around the medium term mean with a frequency of 6-10 years, approximately two life spans of a haddock. When the spawning stock is increasing, the recruitment is decreasing and vice versa.
Kristjansson (loc cit) concludes that "increasing harvest by hard fishing and thus keeping the stock size moderate, is more likely to increase recruitment in the long run, giving a sustainable good harvest". The same could be deduced from the 2006 ICES data. A pattern similar to the Faroese one appears also in the Scottish haddock data. Abundance of stronger and even more numerous recruits is often more probable when the SSB is small, but consists of large, esp., female individuals. Hence, in many cases, it's advisable to maintain an 'old growth' structure in fish populations, since big, old, fat, female fish have been shown to be the best spawners, but are also susceptible to overfishing.
Alas, while the size of SSB is regarded as determining the reproductive capacity of a stock, the practice of reducing fishing yields to keep SSB above certain level often results in under-fishing and economic losses, and also in diminishing recruitment and/or underfed or even sick fish. But, whether SSB produces rich or poor cohorts depends on the external conditions faced by the spawners and or the young stages, from egg to juveniles. Desirably, scientists should look for the reasons (physical, biological) for the respectively poor and abundant recruitments that, in different years, resulted from similar, low or medium SSB levels. Results of such research may help to decide how to rationally react, under different ecological conditions, to low SSB estimates.
Ecology and fish size. Environmental-ecological conditions may affect the age/weight relation in some fishes, as for example is the case with red mullet Mullus barbatus in the Mediterranean, where the descending gradient of favourable environmental conditions from west to east in the Mediterranean is the result of very low primary productivity in the eastern area of this sea, and is responsible for such faunistic phenomena, as the ‘Levantine nanism’ (dwarfism), of Levantine fishes in the Eastern Mediterranean (Sonin et al., 2008). The low and unpredictable food supply in the southeastern Mediterranean leads to early reproduction and smaller fish-body size. The average higher water temperature may also partly explain the dwarfism, as it may cause more intensive metabolic processes in the southeastern fishes, resulting in earlier sexual maturity and curbing of growth, (loc cit).
SCIENCE AND FISHERIES MANAGEMENT
With utmost respect to the great ground-breaking scientist, Prof. Baranov, who reportedly created his model when studying a fish population in a lake characterized by quite stable conditions, and to Ray Beverton and Sydney Holt (1957), the scientists, who pioneered the use of models in the West, and whose model was based on studying a rather stable population of flatfish in British waters, the universal application of mathematical models to fisheries management is highly questionable. This criticism that has long been simmering on small fire recently has become frequent and convincing.
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Dr. Brian J. Rothschild, Dean Emeritus of the University of Massachusetts School for Marine Science and Technology, and one of the most respected American fisheries scientists, proposed in a recent paper, The Overfishing Metaphor, an alternative to the current use of models as a scientific basis for fisheries management. Criticizing devotion to the 50-years-old models and 100-years-old perceptions, he suggests assessing fish stock abundance by frequently measuring rate of capture. “If stocks get too small, we can slow fishing down. If stocks get too big, we can speed it up,” he says. This places the focus on obtaining optimum yield rather than depending on poorly defined criteria such as “overfished” and “overfishing". (Rothschild, 2011).
The disregarded aspects. The approach prevailing in the fisheries science, in addition to ecological factors, can hardly tackle also other aspects, although it sometimes pays them a lip-service. It usually portrays fisheries as if they are made of distinct, separate, unrelated single-species in "disparate" stocks, that can be reliably assessed, and that can be developed ("rebuilt") by regulating catches.
It disregards the element of fishermen's free will and knowledge, in spite that fishermen are all that fisheries management can manage. Fisheries are a dynamic process where fish, fishermen, and ever-changing environment with its innumerable components interact. Fishing people command enormous amounts of accumulated knowledge and experience extremely valuable to augment the scientific data and information. Unfortunately, considered "anecdotal information" they're often ignored.
It sticks with the traditional regulation by minimum mesh and hook size that for over a century has been creaming off stocks the larger and more prolific individuals, while leaving in mostly smaller fish with inferior reproductive qualities (Garcia et al, 2012). Some scientists, as Prof. Mikko Heino of ICES (2003) and an Icelandic scientist, Dr. Jonas Bjarnasson (Private information) assume that this management by size selectivity may lead to genetic evolution of dwarfing the size of individuals in the targeted fish populations. Whether this assumption is right or wrong, fish dwarfing due to over a hundred years of persisting size selectivity is a fact, (Ben-Yami, 2005, 2008; Jørgensen,1990). Garcia et al (loc cit) recommended balanced judicious fishing across all species in the ecosystem: "This strategy, which challenges present management paradigms, distributes a moderate mortality from fishing across the widest possible range of species, stocks, and sizes in an ecosystem, in proportion to their natural productivity, so that the relative size and species composition is maintained."
Another problem is the common practice of managing multi-species fisheries by curtailing mixed and multi-species fisheries by the weaker species, so called ‘choke fish’. This practice is in some cases counter-productive, especially where fishing gear is unable to discriminate between the weak and the strong species, and where they compete over food and space, and predate on each other. What happens is that the stock of the stronger unprotected species may "enjoy" the catch restrictions and keep or even increase its prevalence and its pressure on the weaker "protected" one. Laevastu (loc cit) observes that where one of the managed species is cannibalistic it's advisable to reduce the fishable stock to prevent excessive parental predation on spawn and juveniles. Thus, such "reverse" management, contrary to the "precautionary approach", would prevent the undue catch restrictions and the resulting economic, biological, and social losses.
Management without figures? Not quantifiable information, ignored in the present models, can and should be explained in qualitative, descriptive terms and incorporated in stock assessments. Fishery scientists and managers should study life history and ecology of the targeted fishes, their interaction with other species, and listen to the traditional knowledge and experience of the fishermen concerned. In January, 2014, American scientists of the U.S. NOAA (National Oceanic and Atmospheric
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Administration) Northeast Regional Science Center admitted that their assessment system is inadequate, and called to consider formerly ignored data and information from the industry, from their own social science division, and from the Massachusetts University's studies. All the more that the accuracy of echosounding surveys, which the quantitative assessment methodology is applying, may vacillate by tens of percent both, for technical reasons and because migrations of stocks in true time over and beyond the surveyed and fished areas are hardly accounted for.
Fishery management must be alert for the role of anthropomorphic (due to human activities) factors and for the fluctuating dynamics of the environment. It must take into account, in addition to fishing, polluting and destruction of habitats essential to fish spawning, also factors affecting their growth and survival, as well as all sorts of predation, including cannibalism.
Fuzzy logic. As already stated above, most models can neither explain reliably past nor project future changes in fish stocks, due to missing or highly inaccurate input parameters. They also provide unreliable biomass-assessments. Most are still inherently dependent on equilibrium assumptions and/or predictable top-down drivers, which are transmitted into management considerations.
Pontecorvo, Schrank, Holliday and Olson (2009) analyzed in their book, Fisheries Management: Pandemic Failure, Workable Solutions, the combination of competitiveness of the fishery industry, fish stocks variability, inadequate science, poor understanding of oceanic environment, and the increasing demand that make overfishing highly likely worldwide. While the fishery science has learned much about the biology of individual species, it remains a far cry from understanding the inter-species relationships, not to speak about the "dramatic annual variations in the size of fish stocks", the workings of the marine ecosystems, and how those combine with fishing to affect fish stocks. Having recognized these variabilities, as well as habitat deterioration, and forces of market and technology, the authors highlight the weakness of the biological understanding of fish population dynamics and rule out any long-term status quo. They repudiate laws requiring return to status quo ante, which are powerless over "unruly" fish and their environmental conditions, and emphasize the need for interdisciplinary approach to management. The status quo is impossible to achieve, for the "inherent variability in the ocean environment combined with the variability of fish populations." There's no adequate marine biology theory on which to base fishery management decisions, (and) "the absence of scientific credibility leaves decisions subject to industry opposition, which in time reduces the ability of the fishery services and society to reach the implicit goal". (loc cit).
Therefore, in most cases, exploitation level recommendations are of little or no value in real time, while in model-based stock assessments precision anti-correlates with reliability. The very exactitude of such figures makes them a fallacy. Since models are imperfect to say the least, when data are poor, intelligent and prudent scientists, wherever forced to quantify stock abundance and TACs, have the option of "fuzzy logic" (Zadeh, 1974). It's a methodology, whose proponents point out that the more complex is a system the less is our ability to make precise and significant statements about its behaviour. It applies the concept of intermediate truth values. With roots firm in the real world, fuzzy logic breaks out of the cult of model-driven precision paradigm dominating the "western" fisheries management. (See also: http://en.citizendium.org/wiki/Formal_fuzzy_logic, on line).
The following is a simplified example how a stock assessment arrived at by existing methodology can be represented using fuzzy logic:
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The biomass of a stock is estimated at 100,000 to 200,000MT.
There's a little chance, say 10%, that it is between 100,000 and 120,000 and between 180,000 and 200,000MT.
There's more chance, say, 20% that it is between 120,000 and 130,000 and between 170,000 and 180,000MT.
There's still more chance (about 30%) that it is between 130,000 and 140,000, and between 160,000 and 170,000MT.
And, finally, the best chance is, say 40% that the biomass is between 140,000 and 160,000MT.
A prudent scientist's message to the management should be that stock assessments are approximate, and that all it can do is to operate according to the above "best" range while using other, non-quantitative information, which where reliable, shouldn't be disregarded. Any "precise" stock-assessment figures should always be critically regarded, to say the least.
What's to be done? In view of the above described inadequate science and the consequent pretentious and often counter-productive recommendations that the official scientific establishment is feeding to fisheries managers, the question remains: what's to be done?
Prof Brian Rothschild is only one of several scientists, who have laid bare the various fishing quotas systems ("catch shares" in the USA), for what they actually are. According to press reports (incl. The Gloucester Times), he testified before a Subcommittee at the U.S. House of Representatives that: "…It is difficult to consider the catch share system as having any function other than economic allocation as its sole purpose" …" But, this is the NOAA policy, although the "Magnuson-Stevens Act, states that no "conservation and management measure ... shall have economic allocation as its sole purpose". His recommendation is to "rethink fishery management".
Undoubtedly, in many, especially, coastal fisheries, good management must be tailored case by case and instead of the quantitative stock-assessment and the resulting TAC, administered by capacity, seasons, gear, days-at-sea (DAS), closed areas, and other effort-limiting measures.. Scientists should keep away from the ITQ/Catch Shares fit-for-all craze, for it has nothing to do with their science, but willy-nilly serves to dislocate small- and medium-scale vessels owners, to the benefit of large-scale and corporate owners. Fishing moratoria aimed at protection of fish spawning and nursing grounds can be right only in those cases, where they fit.
The SAMUDRA Newsbrief of Feb. 2014 tells that at the annual meeting of the American Association for the Advancement of Science in San Francisco a team of scientists have proposed a set of "commandments" to protect the world's marine fish populations while ensuring ongoing production of sea food in a sustainable manner. Accordingly, fisheries management science should be "holistic, precautionary and adaptive," consider whole systems, test new
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approaches, while understanding that "it's misguided to think that we can totally understand or completely control entire marine ecosystems", and, for this purpose, (we should) question every assumption, however well-established, for example, that of MSY (maximum sustainable yield), which is "based on flawed concepts".
Other AAAS directives tell to characterize and maintain the natural spatial structure of fish stocks, so that management boundaries match natural boundaries in the sea; monitor and maintain seafloor habitats to make sure fish have food and shelter; maintain resilient ecosystems which are able to withstand occasional shocks; identify and maintain critical food-web connections, including predators and forage species; adapt to ecosystem changes through time, both short-term and on longer cycles of decades or centuries, including global climate change; account for evolutionary changes caused by fishing, which tends to remove large, older fish; and, finally, include the actions of humans and their social and economic systems in all ecological equations.
Fishery management: what for and by whom? While, usually, fishery management's tasks are understood as maintaining conditions that enable supply of fish to people and the well-being of fish producers, preventing fish depletion, and sustaining bio-diversity, in some cases it involves allocation of access to fish resources to different fishery's sectors. Fishing people are often the only element who'd enjoy or suffer from its consequences.
Whatever the scientific advice, political and ideological persuasions of those in power are playing a major role in determining the management's approach. There’re many options, but one social-political question that the management must tackle is: what’s more important? Profits derived from the resource or the number of people making their living of the fishery. Maximizing profits has little to do with scientific or social considerations, but would obviously benefit large scale owners and companies, especially where allowed to operate in coastal waters accessible to small-scale fishermen (Ben-Yami, 2014). However, if the policy is of equitable allocation of fish resources throughout the industry, it may be implemented, as follows (Ben-Yami, 1991):
(i) fish that can be caught by artisanal fishermen should be caught only by them;
(ii) fish that cannot be caught by artisanal fishermen, but can be caught by small-scale commercial fishermen should only be caught by them;
(iii) fish that cannot be caught by small-scale commercial fishermen, but can be caught by medium-scale commercial fishermen should only be caught by them.
(iv) only such resources, which are not accessible to any of the above sectors, or which cannot be feasibly caught, handled, and processed by them, should be allocated to industrial, large-scale fisheries.
This, of course, can't fit every fishery, but it could do as a sort of guiding principle, wherever the management is allowed or instructed to aim at the widest social-national benefits from the fish resources.
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And from the Internet sources::
Fuzzy Logic: http://en.citizendium.org/wiki/Formal_fuzzy_logic.
Images of Top-down Trophic Energy Tranfers: https://www.google.com/search?q=images+for+top-down+energy+transfers&oq=images+for+top-down+energy+transfers&aqs=chrome..69i57.16096j0j9&sourceid=chrome&espv=210&es_sm=93&ie=UTF-8
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Ecosystem approach: World Ocean Review 2013, http://worldoceanreview.com/en/http://worldoceanrevie-
w.com/en/
Also: http://www.worldfishing.net/news101/Comment/ben-yami/new-name,-new-game.
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