scholarly journals Physiological biomarkers and fisheries management

Author(s):  
Pablo Brosset ◽  
Steven J. Cooke ◽  
Quentin Schull ◽  
Verena M. Trenkel ◽  
Philippe Soudant ◽  
...  

AbstractThe benefits of physiological biomarkers, knowledge and concepts are well-established in fish and wildlife management as they confer the ability to understand mechanistic processes, identify cause-and-effect relationships, and develop predictive models. Although this approach is gaining momentum in the context of species conservation, the use of physiological biomarkers in exploited marine fish stock management and recovery plans remains relatively rare. Here, we present five essential issues to consider to implement physiological biomarkers in fisheries management: (i) choice of relevant biomarkers that have a well-known mechanistic basis, (ii) identification of species-specific biomarkers reflecting a meaningful timespan for management, (iii) selection of biomarkers compatible with data collection during routine scientific fisheries surveys, (iv) use of biomarkers as early-warning signals and complementary indicators of population-level changes in life history traits and (v) how physiological biomarkers may help to refine long-term population dynamic projections under climate change and management scenarios. Overall, if based on well-established mechanisms linked to individuals’ fitness, a focus on physiological biomarkers should help to better understand the mechanisms behind stock declines, changes in stock characteristics, and thus more efficiently manage marine fisheries and conserve populations. As this approach is transferable among species, locations, and times, the integration of physiological biomarkers in fisheries science has the potential to more broadly enhance assessments and management of fish stocks.

2020 ◽  
Vol 117 (4) ◽  
pp. 2218-2224 ◽  
Author(s):  
Ray Hilborn ◽  
Ricardo Oscar Amoroso ◽  
Christopher M. Anderson ◽  
Julia K. Baum ◽  
Trevor A. Branch ◽  
...  

Marine fish stocks are an important part of the world food system and are particularly important for many of the poorest people of the world. Most existing analyses suggest overfishing is increasing, and there is widespread concern that fish stocks are decreasing throughout most of the world. We assembled trends in abundance and harvest rate of stocks that are scientifically assessed, constituting half of the reported global marine fish catch. For these stocks, on average, abundance is increasing and is at proposed target levels. Compared with regions that are intensively managed, regions with less-developed fisheries management have, on average, 3-fold greater harvest rates and half the abundance as assessed stocks. Available evidence suggests that the regions without assessments of abundance have little fisheries management, and stocks are in poor shape. Increased application of area-appropriate fisheries science recommendations and management tools are still needed for sustaining fisheries in places where they are lacking.


Author(s):  
Rashid Sumaila

The economic tool of individual transferable quotas (ITQs) gives their owners exclusive and transferable rights to catch a given portion of the total allowable catch (TAC) of a given fish stock. Authorities establish TACs and then divide them among individual fishers or firms in the form of individual catch quotas, usually a percentage of the TAC. ITQs are transferable through selling and buying in an open market. The main arguments by proponents of ITQs is that they eliminate the need to “race for the fish” and thus increase economic returns while eliminating overcapacity and overfishing. In general, fisheries’ management objectives consist of ecological (sustainable use of fish stocks), economic (no economic waste), and social (mainly the equitable distribution of fisheries benefits) issues. There is evidence to show that ITQs do indeed reduce economic waste and increase profits for those remaining in fisheries. However, they do not perform well in terms of sustainability or socially. A proposal that integrates ITQs in a comprehensive and effective ecosystem-based fisheries management system that is more likely to perform much better than ITQs with respect to ecological, economic, and social objectives is presented in this article.


Author(s):  
Ray Hilborn ◽  
Ulrike Hilborn

Over the last 2 decades, the scientific and popular media have been bombarded by gloom-and-doom stories on the future of fisheries, the status of fish stocks, and the impact of fishing on marine ecosystems. Dozens of certification and labeling schemes have emerged to advise consumers on what seafood is sustainable. In recent years, an opposing narrative has emerged emphasizing the success of fisheries management in many places, the increasing abundance of fish stocks in those places, and the prescription for sustainable fisheries. However, there has been no comprehensive survey of what really constitutes sustainability in fisheries, fish stock status, success and failures of management, and consideration of the impacts of fishing on marine ecosystems. This book will explore very different perspectives on sustainability and bring together the data from a large number of studies to show where fish stocks are increasing, where they are declining, the consequences of alternative fisheries management regimes, and what is known about a range of fisheries issues such as the impacts of trawling on marine ecosystems. Aimed principally at a general audience that is already interested in fisheries but seeks both a deeper understanding of what is known about specific issues and an impartial presentation of all of the data rather than selected examples used to justify a particular perspective or agenda. It will also appeal to the scientific community eager to know more about marine fisheries and fishing data, and serve as the basis for graduate seminars on the sustainability of natural resources.


1981 ◽  
Vol 38 (12) ◽  
pp. 1856-1866 ◽  
Author(s):  
R. A. Ryder ◽  
S. R. Kerr ◽  
W. W. Taylor ◽  
P. A. Larkin

Genotypes are variable among fish stocks, and these limit potential niche. In turn, realized niche is further constrained by the interaction of abiotic and biotic environmental factors, together with fishery exploitation. Selection pressures by these three factors provide feedback on genotypes, modifying potential niches. The steady-state consequence of this process is a harmonic community of co-evolved stocks. Using community size structure as one of our criteria, we trace the effects of the major classes of perturbation on harmonic communities, and discuss their management implications.Key words: harmonic community, co-evolution, fish stock, management, genetics, biotic and abiotic environmental factors, niche


1981 ◽  
Vol 38 (12) ◽  
pp. 1889-1898 ◽  
Author(s):  
J. A. MacLean ◽  
D. O. Evans

This paper examines the concept and definition of fish stocks and the processes that influence discreteness of these stocks in light of the tactics necessary for the application of the concept in management. Two approaches to the definition of stocks are discussed. These differ in the extent to which management inputs other than biological ones are considered. We consider definition to be less important than the adoption and development of a stock concept to provide a genetic perspective for fisheries management. The two central levels of the stock concept — the subdivision of species into local populations and the adaptive nature of genetic differences between these populations — are discussed with respect to the interlinked set of ecological and genetic processes that result in subdivision and determine the discreteness of these stocks. Genetic discreteness usually implies some restriction of gene flow, and spatial and temporal mechanisms of isolation are discussed with examples from the STOCS symposium. The structure of subdivided populations is seen as the result of behavioral processes that are one component of a set of coadapted traits, which collectively constitute a life history strategy. The necessity for managers to develop a new integrated view of species, which incorporates both ecological and genetic arguments, is discussed.Key words: stock concept, life history, gene flow, ecological and genetic discreteness, local adaptation stock management


2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Anthony D. Hawkins

In recent years there has been increasing concern over the state of fish stocks, especially those that support key fisheries and supply food to many consumers. There is also concern over the state of aquatic environments, and the effects of climate change. Fisheries management is controlled by government agencies, often cooperating with similar agencies from other nations. This paper deals with the need for expert advice on fisheries, involving fishers as well as scientists. Mention is made of a Fisheries Partnership set up in Europe, bringing fishers and scientists together with other stakeholders to discuss the problems of managing fish stocks. The partnership was especially successful in improving relationships between fishers and scientists, and made significant improvements to some fish stock assessments. European Regional Advisory Councils were later established to play a similar role. They are providing significant advice on fisheries, but they do not yet play a key role in actual management. It is important to consider how stakeholders and scientists can become more actively involved in fisheries management. There is a crucial need to develop new, more participatory ways of managing fisheries.


Author(s):  
Ken H. Andersen

This chapter provides some context on the overall themes and theory of this volume. Throughout, the theory is applied to relevant problems in fisheries science: impact of fishing on demography, fisheries reference points, evolutionary impact assessments, stock recovery, ecosystem-based fisheries management, and so on, as well as to basic ecological and evolutionary questions. The chapter begins by addressing the motivations for a new theory of fish stocks and fish communities. It also considers what problems such a theory should address and how such a theory can be formulated. From here, the chapter discusses what makes a good theory and the peculiar challenges fish ecology represents.


2013 ◽  
Vol 71 (5) ◽  
pp. 1187-1197 ◽  
Author(s):  
Christian Möllmann ◽  
Martin Lindegren ◽  
Thorsten Blenckner ◽  
Lena Bergström ◽  
Michele Casini ◽  
...  

Abstract Theory behind ecosystem-based management (EBM) and ecosystem-based fisheries management (EBFM) is now well developed. However, the implementation of EBFM exemplified by fisheries management in Europe is still largely based on single-species assessments and ignores the wider ecosystem context and impact. The reason for the lack or slow implementation of EBM and specifically EBFM is a lack of a coherent strategy. Such a strategy is offered by recently developed integrated ecosystem assessments (IEAs), a formal synthesis tool to quantitatively analyse information on relevant natural and socio-economic factors, in relation to specified management objectives. Here, we focus on implementing the IEA approach for Baltic Sea fish stocks. We combine both tactical and strategic management aspects into a single strategy that supports the present Baltic Sea fish stock advice, conducted by the International Council for the Exploration of the Sea (ICES). We first review the state of the art in the development of IEA within the current management framework. We then outline and discuss an approach that integrates fish stock advice and IEAs for the Baltic Sea. We intentionally focus on the central Baltic Sea and its three major fish stocks cod (Gadus morhua), herring (Clupea harengus), and sprat (Sprattus sprattus), but emphasize that our approach may be applied to other parts and stocks of the Baltic, as well as other ocean areas.


1987 ◽  
Vol 44 (S2) ◽  
pp. s360-s370 ◽  
Author(s):  
Niels Daan

Development of multispecies virtual population analysis (MSVPA), which assesses interspecific and intraspecific predation through an analysis of stomach contents, has verified the hypothesis that predation among exploited fish species contributes significantly to their natural mortality and that predation, and thus natural mortality, is inherently variable from year to year. In single-species virtual population analysis (SSVPA), natural mortality is assumed to be constant. MSVPA also suggests that natural mortality among young fish after recruitment is much higher than previously thought. Although catch quotas based on predictions of short-term catches from multispecies assessments would appear to differ little from those derived from single-species assessments, and certain problems remain to be resolved before multispecies assessments can be accepted for fish stock management, the method has considerable implications for management. For instance, it suggests that effects of mesh sizes and bycatch on fisheries need reevaluation and that year class strength may not be as fixed as previously assumed.


2013 ◽  
Vol 70 (4) ◽  
pp. 743-754 ◽  
Author(s):  
Dankert W. Skagen ◽  
Mette Skern-Mauritzen ◽  
Dorothy Dankel ◽  
Katja Enberg ◽  
Olav S. Kjesbu ◽  
...  

Abstract Skagen, D. W., Skern-Mauritzen, M., Dankel, D., Enberg, K., Kjesbu, O. S., and Nash, R. D. M. 2013. A simulation framework for evaluating fisheries management decisions using environmental information. – ICES Journal of Marine Science, 70: 743–754. The population dynamics of marine fish stocks are influenced by both physical and biological conditions. Yet, such environmental impacts on stock dynamics, and hence stock production, are rarely included in applied fisheries management. To test the utility of taking ecosystem information into account in management decisions requires efficient tools. We propose a simulation framework for evaluating fisheries management schemes that use environmental information as part of the decision basis. A key feature is to link environmental signals to parameters in functions that define the population dynamics. This allows a direct incorporation of environmental drivers into models of population dynamic processes and emphasizes the need for a quantitative understanding of the influence of environmental drivers on such processes. The utility of the simulation framework is demonstrated through a worked example with different management scenarios, where decisions to increase or decrease the exploitation rely on environmental indicators only, or also on information on stock abundance. In this example, a management that was based on indicators only, without updated measures of the state of the stock itself, failed to respond adequately to changes in stock productivity.


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