Nothing as Practical as a Good Theory

2019 ◽  
pp. 1-12
Author(s):  
Ken H. Andersen
Keyword(s):  
Fisheries Management ◽  
Fish Communities ◽  
Reference Points ◽  
Fish Ecology ◽  
Good Theory ◽  
Fish Stocks ◽  
Fisheries Science ◽  
Ecosystem Based Fisheries Management ◽  
Stock Recovery

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.

Marine ecosystem assessment in a fisheries management context

2002 ◽  
Vol 59 (9) ◽  
pp. 1429-1440 ◽  
Author(s):  
Jason S Link ◽  
Jon K.T Brodziak ◽  
Steve F Edwards ◽  
William J Overholtz ◽  
David Mountain ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Marine Ecosystem ◽  
Single Species ◽  
Reference Points ◽  
System Level ◽  
Multivariate Statistical Methods ◽  
Multivariate Statistical ◽  
Management Context ◽  
Ecosystem Level ◽  
Ecosystem Based Fisheries Management

We examined a suite of abiotic, biotic, and human metrics for the northeast U.S. continental shelf ecosystem at the aggregate, community, and system level (>30 different metrics) over three decades. Our primary goals were to describe ecosystem status, to improve understanding of the relationships between key ecosystem processes, and to evaluate potential reference points for ecosystem-based fisheries management (EBFM). To this end, empirical indicators of ecosystem status were examined and standard multivariate statistical methods were applied to describe changes in the system. We found that (i) a suite of metrics is required to accurately characterize ecosystem status and, conversely, that focusing on a few metrics may be misleading; (ii) assessment of ecosystem status is feasible for marine ecosystems; (iii) multivariate points of reference can be determined for EBFM; and (iv) the concept of reference directions could provide an ecosystem level analog to single-species reference points.

scholarly journals Effective fisheries management instrumental in improving fish stock status

2020 ◽  
Vol 117 (4) ◽  
pp. 2218-2224 ◽  
Author(s):  
Ray Hilborn ◽  
Ricardo Oscar Amoroso ◽  
Christopher M. Anderson ◽  
Julia K. Baum ◽  
Trevor A. Branch ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Marine Fish ◽  
Food System ◽  
Fish Stock ◽  
Management Tools ◽  
Fish Stocks ◽  
Fisheries Science ◽  
The World ◽  
Fish Catch ◽  
Intensively Managed

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.

scholarly journals Reproductive hyperallometry and managing the world’s fisheries

2021 ◽  
Vol 118 (34) ◽  
pp. e2100695118
Author(s):  
Dustin J. Marshall ◽  
Michael Bode ◽  
Marc Mangel ◽  
Robert Arlinghaus ◽  
E. J. Dick
Keyword(s):  
Fisheries Management ◽  
Management Strategies ◽  
Reference Points ◽  
Target Level ◽  
Fish Stocks ◽  
Global Food Security ◽  
Common Reference ◽  
Future Assessment ◽  
Traditional Approaches ◽  
Global Food

Marine fisheries are an essential component of global food security, but many are close to their limits and some are overfished. The models that guide the management of these fisheries almost always assume reproduction is proportional to mass (isometry), when fecundity generally increases disproportionately to mass (hyperallometry). Judged against several management reference points, we show that assuming isometry overestimates the replenishment potential of exploited fish stocks by 22% (range: 2% to 78%) for 32 of the world’s largest fisheries, risking systematic overharvesting. We calculate that target catches based on assumptions of isometry are more than double those based on assumptions of hyperallometry for most species, such that common reference points are set twice as high as they should be to maintain the target level of replenishment. We also show that hyperallometric reproduction provides opportunities for increasing the efficacy of tools that are underused in standard fisheries management, such as protected areas or harvest slot limits. Adopting management strategies that conserve large, hyperfecund fish may, in some instances, result in higher yields relative to traditional approaches. We recommend that future assessment of reference points and quotas include reproductive hyperallometry unless there is clear evidence that it does not occur in that species.

How to Make Individual Transferable Quotas Work Economically, Socially, and Environmentally

2018 ◽  
Author(s):  
Rashid Sumaila
Keyword(s):  
Fisheries Management ◽  
Sustainable Use ◽  
Fish Stock ◽  
Open Market ◽  
Economic Returns ◽  
Total Allowable Catch ◽  
Fish Stocks ◽  
Individual Transferable Quotas ◽  
Management Objectives ◽  
Ecosystem Based Fisheries Management

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.

An Examination of Progress Toward Ecosystem-Based Management of Living Marine Resources in the U.S.

2021 ◽  
pp. 611-650
Author(s):  
Jason S. Link ◽  
Anthony R. Marshak
Keyword(s):  
United States ◽  
Fisheries Management ◽  
Ecosystem Processes ◽  
Marine Ecosystems ◽  
Environmental Indicators ◽  
Reference Points ◽  
Marine Fishery ◽  
Ecosystem Level ◽  
Ecosystem Based Fisheries Management ◽  
The U.S

This chapter presents a cumulative examination of socioeconomic, governance, ecological, and environmental indicators among the eight major United States (U.S.) marine fishery ecosystems, 26 U.S. subregions, and 14 U.S. participatory regional fisheries management organization (RFMO) jurisdictions. Based on these indicators and as one might expect, some regions are making greater progress toward ecosystem-based fisheries management (EBFM) than others, but in all U.S. marine ecosystems there has been notable progress toward EBFM, albeit on different facets for different regions. Common areas of notable progress toward EBFM are observed around the nation in areas of implementing ecosystem-level planning and advancing understanding of ecosystem processes. Overall, it appears that more inherently productive marine ecosystems tend to have greater biomass, fisheries landings, proportional LMR-based employments, and fisheries revenue. More work remains in areas of ecosystem and community resilience, as well as broader consideration of more systematic measures for a fisheries ecosystem (especially ecosystem-level reference points). Several areas of common challenges and anticipated concerns are identified, with an eye toward focusing efforts on addressing these issues.

scholarly journals A Conceptual Framework for Incorporating Human Dimensions Into Integrated Ecosystem Assessments

2021 ◽  
Vol 8 ◽  
Author(s):  
Marysia Szymkowiak
Keyword(s):  
Conceptual Framework ◽  
Fisheries Management ◽  
Well Being ◽  
Detailed Examination ◽  
Human Dimensions ◽  
Iterative Approach ◽  
Ample Evidence ◽  
Fisheries Science ◽  
Ecosystem Assessments ◽  
Ecosystem Based Fisheries Management

The evolution of fisheries science and management toward an ecosystem perspective necessitates the meaningful incorporation of human dimensions. Whereas great strides have been made over the last several decades at moving toward ecosystem based fisheries management (EBFM), largely through the development of integrated ecosystem assessments (IEAs), the inclusion of human dimensions into these efforts has often been fragmentary and, in juxtaposition to the biophysical dynamics, sometimes even seemingly superficial. This presents a great challenge to the accuracy and applicability of these results, as the lack of appropriate incorporation of humans can be problematic in terms of both social and biophysical consequences. This study systematically documents current social science understanding of the multiple human dimensions that should be incorporated within ecosystem assessments and the overall approach to each of these within IEAs and other EBFM efforts. These dimensions include the multi-faceted nature of human well-being, heterogeneity in human well-being derived from fisheries, adaptive behaviors, and cumulative effects. The systematic inclusion of these dimensions into IEAs is then laid out in a conceptual framework that details how a perturbation reverberates through a fisheries system and the iterative approach that should be undertaken to understand its impacts on human dimensions. This framework is supplemented with a data collection scheme that is intended to facilitate operationalization. The detailed examination of incorporating human dimensions within IEAs presented in this study should further resonate with other ecosystem assessment efforts, providing not just ample evidence of the need for moving beyond simplistic assumptions of human homogeneity but a means of systematically integrating a more realistic and representative perspective.

scholarly journals Implementing ecosystem-based fisheries management: from single-species to integrated ecosystem assessment and advice for Baltic Sea fish stocks

2013 ◽  
Vol 71 (5) ◽  
pp. 1187-1197 ◽  
Author(s):  
Christian Möllmann ◽  
Martin Lindegren ◽  
Thorsten Blenckner ◽  
Lena Bergström ◽  
Michele Casini ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Fisheries Management ◽  
Gadus Morhua ◽  
Single Species ◽  
Clupea Harengus ◽  
Fish Stock ◽  
Fish Stocks ◽  
The Baltic ◽  
Ecosystem Based Fisheries Management ◽  
Sea Fish

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.

scholarly journals A multi-stock harvest control rule based on “pretty good yield” ranges to support mixed-fisheries management

2019 ◽  
Author(s):  
Dorleta Garcia ◽  
Paul J Dolder ◽  
Ane Iriondo ◽  
Claire Moore ◽  
Raúl Prellezo ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Stock Assessment ◽  
Holistic Approach ◽  
Fishing Mortality ◽  
Fish Stocks ◽  
Control Rule ◽  
Harvest Control Rule ◽  
The Impact ◽  
Ecosystem Based Fisheries Management

Abstract Advice for commercially exploited fish stocks is usually given on a stock-by-stock basis. In light of the ecosystem-based fisheries management, the need to move towards a holistic approach has been largely acknowledged. In addition, the discard bans in some countries requires consistent catch advice among stocks to mitigate choke species limiting fisheries activity. In this context, in 2015, the European Commission proposed the use of fishing mortality ranges around fishing mortality targets to give flexibility to the catch advice system and improve the use of fishing opportunities in mixed-fisheries. We present a multi-stock harvest control rule (HCR) that uses single stock assessment results and fishing mortality ranges to generate a consistent catch advice among stocks. We tested the performance of the HCR in two different case studies. An artificial case study with three stocks exploited simultaneously by a single fleet and the demersal mixed-fishery operating in Bay of Biscay and Celtic Sea. The HCR produced consistent catch advice among stocks when there was only a single fleet exploiting them. Even more, the HCR removed the impact of the discard ban. However, in a multi-fleet framework the performance of the HCR varied depending on the characteristics of the fleets.

Recent international agreements and the precautionary approach: new directions for fisheries management science

1998 ◽  
Vol 55 (6) ◽  
pp. 1545-1552 ◽  
Author(s):  
Laura J Richards ◽  
Jean-Jacques Maguire
Keyword(s):  
Fisheries Management ◽  
Scientific Information ◽  
Decision Rules ◽  
International Agreements ◽  
Reference Points ◽  
Future Research ◽  
Specific Reference ◽  
Precautionary Approach ◽  
Ecosystem Impacts ◽  
Fish Stocks

The dynamics of exploited fish populations can be highly uncertain and the precautionary approach to fisheries management addresses such uncertainties. The precautionary approach is now embodied in several international agreements, including (i) the UN Straddling Fish Stocks and Highly Migratory Fish Stocks Agreement and (ii) the FAO Code of Conduct. We discuss how application of these agreements will change the daily operations of many fisheries agencies. Contrary to past practices, the absence of adequate scientific information can no longer be a reason for postponing or failing to take conservation measures. Future harvest strategies will be based on stock-specific reference points and predefined decision rules. However, more research is required to quantify uncertainties associated with reference point definitions and their practical application in a management context. In addition, future research will emphasize environmental issues with extensive data requirements, such as ecosystem impacts of fishing. Data collection will remain a core business activity; agencies must address the costs of maintaining shared and documented data archives over the long term.

scholarly journals The evolution of New Zealand's fisheries science and management systems under ITQs†

2013 ◽  
Vol 71 (2) ◽  
pp. 204-215 ◽  
Author(s):  
Pamela M. Mace ◽  
Kevin J. Sullivan ◽  
Martin Cryer
Keyword(s):  
New Zealand ◽  
Fisheries Management ◽  
Marine Mammals ◽  
Reference Points ◽  
Management Systems ◽  
Fishing Industry ◽  
Comprehensive Management ◽  
Fisheries Science ◽  
Stock Status ◽  
Initial Design

Abstract Mace, P. M., Sullivan, K. J., and Cryer, M. 2014. The evolution of New Zealand's fisheries science and management systems under ITQs. – ICES Journal of Marine Science, 71: 204–215. New Zealand implemented a comprehensive management system using individual transferable quotas in 1986 that has been instrumental in guiding the roles, responsibilities, and accountabilities of fisheries science, fisheries management, and the fishing industry ever since. However, at the time of the initial design, a number of issues were not adequately considered. These relate mainly to the dynamic nature of fish stocks, multispecies considerations, and environmental and other externalities. Subsequent efforts to address these issues have been challenging and many are not yet fully resolved. The outcomes for fisheries science, stock status, multispecies management, ecosystem effects, and fishing industry accountability have been mixed, although mostly positive. Fisheries science, fisheries management, and the fishing industry have all become much more professionalized and their activities have been increasingly streamlined. New initiatives to further improve the system continue to be researched and implemented. Overall, we believe that the positives considerably outweigh the negatives. The initial design has proved to be a system that can be built upon. Comparing New Zealand with most of the rest of the world, key positive outcomes for preventing overfishing are the current lack of significant overcapacity in most fisheries, the development of biological reference points and a harvest strategy standard, the favourable stock status for the majority of stocks with known status, and the development and implementation of comprehensive risk assessments and management plans to protect seabirds and marine mammals.

Sign in / Sign up

Export Citation Format

Share Document