scholarly journals Incorporating environmental forcing in developing ecosystem-based fisheries management strategies

2019 ◽  
Vol 77 (2) ◽  
pp. 500-514 ◽  
Author(s):  
Chuanbo Guo ◽  
Caihong Fu ◽  
Norm Olsen ◽  
Yi Xu ◽  
Arnaud Grüss ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Management Strategies ◽  
Mortality Rates ◽  
Marine Ecosystems ◽  
Ecosystem Structure ◽  
Fishing Mortality ◽  
Management Options ◽  
Environmental Forcing ◽  
Ecosystem Effects ◽  
Ecosystem Level

Abstract This study incorporated two pathways of environmental forcing (i.e. “larval mortality forcing” and “somatic growth forcing”) into an end-to-end ecosystem model (Object-oriented Simulator of Marine ecOSystEms, OSMOSE) developed for the Pacific North Coast Integrated Management Area (PNCIMA) off western Canada, in order to evaluate alternative fisheries management strategies under environmental changes. With a suite of ecosystem-level indicators, the present study first compared the ecosystem effects of different pathways of environmental forcing scenarios; and then evaluated the alternative fisheries management strategies which encompassed a series of fishing mortality rates relative to FMSY (the fishing mortality rate that produces maximum sustainable yield) and a set of precautionary harvest control rules (HCRs). The main objectives of this study were to (i) explore the ecosystem effects of different environmental forcing scenarios; (ii) identify the impacts of different fishing mortality rates on marine ecosystem structure and function; and (iii) evaluate the ecosystem-level performance of various levels of precautionary HCRs. Results indicated that different pathways of environmental forcing had different ecosystem effects and incorporating appropriate HCRs in the fisheries management process could help maintain ecosystem health and sustainable fisheries. This study provides important information on future fisheries management options within similar marine ecosystems that are facing global changes.

scholarly journals Ecosystem-based reference points under varying plankton productivity states and fisheries management strategies

2019 ◽  
Vol 76 (7) ◽  
pp. 2045-2059 ◽  
Author(s):  
Chuanbo Guo ◽  
Caihong Fu ◽  
Robyn E Forrest ◽  
Norm Olsen ◽  
Huizhu Liu ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Management Strategies ◽  
Reference Points ◽  
Productivity Change ◽  
Pacific Herring ◽  
Fishing Mortality ◽  
Pacific Cod ◽  
Sustainable Fisheries ◽  
Ecosystem Effects ◽  
Plankton Biomass

Abstract In the context of ecosystem-based fisheries management, which should consider changing and uncertain environmental conditions, the development of ecosystem-based biological reference points (EBRPs) to account for important multi-species (MS) interactions, fishery operations, and climate change, is of paramount importance for sustainable fisheries management. However, EBRPs under varying plankton productivity states and fisheries management strategies are seldom developed, and the ecosystem effects of these changes are still largely unknown. In this study, ecosystem-based FMSY (fishing mortality rate at MSY) values were estimated within an end-to-end ecosystem model (OSMOSE) for three focused fish species (Pacific Herring, Clupea pallasii; Pacific Cod, Gadus macrocephalus; Lingcod, Ophiodon elongatus) under three plankton productivity states of differing plankton biomass at high, current, and low levels. In addition, ecosystem effects were compared across different plankton productivity and fisheries management strategies with the latter consisting of two fishery scenarios (i.e. single-species-focused (SS) and MS-focused), various fishing mortality rates, and two harvest policies (with and without harvest control rules, HCRs). Main findings of this study include: (i) plankton productivity change affected the values of ecosystem-based FMSY, which increased as plankton productivity states changed from low to high plankton biomass; (ii) ecosystem-based FMSY for Pacific Herring and Pacific Cod stocks increased when fishery scenarios shifted from SS-focused to MS-focused; (iii) fisheries management incorporating HCR yielded more stable system catch and system biomass; and (iv) high plankton biomass combined with fisheries management using HCR could maintain stable ecosystem production and sustainable fisheries. Based on our findings, we highlight possible adaptive fisheries management strategies in the face of future climate and ocean changes. Overall, EBRPs complement SS stock assessments by incorporating key ecological processes and ecosystem properties, thus providing supporting evidence for better incorporation of ecosystem considerations into scientific advice for sustainable fisheries management.

scholarly journals A Review Characterizing 25 Ecosystem Challenges to Be Addressed by an Ecosystem Approach to Fisheries Management in Europe

2021 ◽  
Vol 7 ◽  
Author(s):  
Francois Bastardie ◽  
Elliot J. Brown ◽  
Eider Andonegi ◽  
Robert Arthur ◽  
Esther Beukhof ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Marine Mammals ◽  
Habitat Degradation ◽  
Sustainable Use ◽  
Ecosystem Approach ◽  
Marine Ecosystems ◽  
Science Literature ◽  
Management Options ◽  
Ecosystem Monitoring ◽  
Ecosystem Effects

The impacts of fisheries on ocean resources are no longer considered in isolation but should account for broader ecosystem effects. However, ongoing ecosystem-wide changes added to the inherent dynamics of marine ecosystems, create challenges for fisheries and fisheries management by affecting our ability to ensure future fishing opportunities and sustainable use of the seas. By reviewing a corpus of fisheries science literature, we contribute to informing managers and policymakers with considerations of the various threats to fisheries and the marine ecosystems that support them. We identify and describe 25 ecosystem challenges and 7 prominent families of management options to address them. We capture the challenges acting within three broad categories: (i) fishing impacts on the marine environments and future fishing opportunities, (ii) effects of environmental conditions on fish and fishing opportunities, and (iii) effects of context in terms of socioeconomics, fisheries management, and institutional set-up on fisheries. Our review shows that, while most EU fisheries are facing a similar array of challenges, some of them are specific to regions or individual fisheries. This is reflected in selected regional cases taking different perspectives to exemplify the challenges along with fishery-specific cases. These cases include the dramatic situation of the Baltic Sea cod, facing an array of cumulative pressures, the multiple and moving ecosystem interactions that rely on the North Sea forage fish facing climate change, the interaction of fishing and fish stocks in a fluctuating mixed fishery in the Celtic Sea, the bycatch of marine mammals and seabirds and habitat degradation in the Bay of Biscay, and finally the under capacity and lack of fundamental knowledge on some features of the EU Outermost Regions. In addition to these ecoregion specific findings, we discuss the outcomes of our review across the whole of European waters and we conclude by recognizing that there are knowledge gaps regarding the direction of causality, nonlinear responses, and confounding effects. All of the challenges we identify and characterize may guide further data collection and research coordination to improve our fundamental understanding of the system and to monitor real changes within it, both of which are required to inform an Ecosystem Approach to Fisheries Management (EAFM). An European EAFM could build upon an array of management measures currently tailored for fisheries management only, including promoting funding interdisciplinary research and ecosystem monitoring. Such integrative management should reduce uncertainties in environmental, social and economic trends, and lower the risk for disruptive events or ecosystem effects with far-reaching consequences, including a shift toward less productive marine ecosystems.

Relationships between Common Biological Reference Points Used as Thresholds and Targets of Fisheries Management Strategies

1994 ◽  
Vol 51 (1) ◽  
pp. 110-122 ◽  
Author(s):  
Pamela M. Mace
Keyword(s):  
Life History ◽  
Density Dependence ◽  
Fisheries Management ◽  
Management Strategies ◽  
Mortality Rates ◽  
Reference Points ◽  
Fishing Mortality ◽  
New Methods ◽  
Life History Characteristics ◽  
Target Fishing

Relationships between various biological reference points (BRPs) used to define thresholds and targets of fisheries management strategies were examined for a range of combinations of life history characteristics. Rank orderings of the selected BRPs were strongly influenced by the degree of density dependence in the underlying spawning–recruitment (S–R) relationship. The validity of F0.1, Fmax, F20% (the fishing mortality at which spawning per recruit is 20% of the maximum), and other reference fishing mortality rates as approximations to Fmsy or as thresholds of overfishing is highly dependent on life history characteristics, particular the degree of density dependence in the S–R relationship. It is recommended that F40% be adopted as a target fishing mortality rate when the S–R relationship is unknown and that threshold levels of biomass be related to the estimated or assumed degree of density dependence in the S–R relationship. Two new methods of calculating threshold biomass levels are suggested as alternatives to the familiar 20% B0 rule.

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 Comparing data-based indicators across upwelling and comparable systems for communicating ecosystem states and trends

2009 ◽  
Vol 67 (4) ◽  
pp. 807-832 ◽  
Author(s):  
Lynne J. Shannon ◽  
Marta Coll ◽  
Dawit Yemane ◽  
Didier Jouffre ◽  
Sergio Neira ◽  
...  
Keyword(s):  
Mediterranean Ecosystems ◽  
Complex Model ◽  
Environmental Forcing ◽  
Ecosystem Effects ◽  
The Status ◽  
Ecosystem Level ◽  
Trends Over Time ◽  
Fishing Impacts ◽  
Proper Interpretation ◽  
Ecosystem State

Abstract Shannon, L. J., Coll, M., Yemane, D., Jouffre, D., Neira, S., Bertrand, A., Diaz, E., and Shin, Y-J. 2010. Comparing data-based indicators across upwelling and comparable systems for communicating ecosystem states and trends. – ICES Journal of Marine Science, 67: 807–832. A suite of ecological indicators was selected for communicating, in a comparable way, how fishing affects the state of several upwelling ecosystems and others in which small pelagic fish play key ecological roles. Detailed background and understanding of system-specific processes and changes is needed for proper interpretation of results. In particular, environmental forcing is important in driving dynamics in upwelling systems; fishing impacts cannot be understood without understanding the corresponding dynamics of the environment. The Saharan Coastal (Morocco) and southern Benguela, both having experienced upsurges in low-trophic-level species, differed from other ecosystems when considering indicator trends. The ecosystem off Portugal emerged as showing reduced signs of fishing impacts in recent years, although the change may also be reflecting climate change favouring recruitment and abundance of demersal stocks. The indicator suite confirmed general understanding that the Mediterranean ecosystems have been notably degraded for several decades. Results and conclusions from this descriptive synthesis are compared with other comparisons of more complex, model-derived indicators. Even in upwelling and comparable systems, the simple data-based indicators are useful in synthesizing information on the status of an ecosystem, in particular on the ecosystem effects of fishing, to provide an ecological diagnosis at the ecosystem level, to be used in decision-making. Indicators of recent ecosystem state and trends over time are needed to assess the effects of fishing, but more indicators measuring biodiversity attributes and environmental change would complement the suite, providing fuller assessment of the status of upwelling and comparable ecosystems.

scholarly journals Comparative analysis of European wide marine ecosystem shifts: a large-scale approach for developing the basis for ecosystem-based management

2011 ◽  
Vol 7 (4) ◽  
pp. 484-486 ◽  
Author(s):  
Christian Möllmann ◽  
Alessandra Conversi ◽  
Martin Edwards
Keyword(s):  
Large Scale ◽  
Marine Ecosystem ◽  
Management Strategies ◽  
Marine Ecosystems ◽  
Regime Shifts ◽  
Comparative Approach ◽  
The Black Sea ◽  
Ecosystem Structure ◽  
Ecosystem Based Management ◽  
The North

Abrupt and rapid ecosystem shifts (where major reorganizations of food-web and community structures occur), commonly termed regime shifts, are changes between contrasting and persisting states of ecosystem structure and function. These shifts have been increasingly reported for exploited marine ecosystems around the world from the North Pacific to the North Atlantic. Understanding the drivers and mechanisms leading to marine ecosystem shifts is crucial in developing adaptive management strategies to achieve sustainable exploitation of marine ecosystems. An international workshop on a comparative approach to analysing these marine ecosystem shifts was held at Hamburg University, Institute for Hydrobiology and Fisheries Science, Germany on 1–3 November 2010. Twenty-seven scientists from 14 countries attended the meeting, representing specialists from seven marine regions, including the Baltic Sea, the North Sea, the Barents Sea, the Black Sea, the Mediterranean Sea, the Bay of Biscay and the Scotian Shelf off the Canadian East coast. The goal of the workshop was to conduct the first large-scale comparison of marine ecosystem regime shifts across multiple regional areas, in order to support the development of ecosystem-based management strategies.

Missing the target: uncertainties in achieving management goals in fisheries on Fraser River, British Columbia, sockeye salmon (Oncorhynchus nerka)

2006 ◽  
Vol 63 (12) ◽  
pp. 2722-2733 ◽  
Author(s):  
Carrie A Holt ◽  
Randall M Peterman
Keyword(s):  
British Columbia ◽  
Fisheries Management ◽  
Return Migration ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Simulation Models ◽  
Mortality Rates ◽  
Fraser River ◽  
Management Options ◽  
Fishing Regulations

In sockeye salmon (Oncorhynchus nerka) fisheries, management targets are rarely achieved exactly, thereby creating uncertainties about outcomes from implementing fishing regulations. Although this type of uncertainty may be large, it is seldom incorporated into simulation models that evaluate management options. One objective of this study was to quantify the deviations that occur between realized and target mortality rates (i.e., the target fraction of adult recruits that die each year during return migration, mostly due to harvesting) in fisheries for sockeye salmon from the Fraser River, British Columbia. We found that for some sockeye stocks, realized mortality rates were higher than targets when recruitment was low (resulting in conservation concerns) and lower than targets when recruitment was high (resulting in foregone catch). Scientists and managers can at least partially account for effects of such deviations between realized and target mortality rates (outcome uncertainties) by choosing target harvest rules that reflect typical patterns in those deviations. We derived a method to permit modelers to incorporate those patterns into analyses of management options.

scholarly journals Ecosystem models of Lake Victoria (East Africa): exploring the sensitivity of ecosystem effects of fishing to model choice

2018 ◽  
Author(s):  
Vianny Natugonza ◽  
Cameron Ainsworth ◽  
Erla Sturludóttir ◽  
Laban Musinguzi ◽  
Richard Ogutu-Ohwayo ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Species Interactions ◽  
Lake Victoria ◽  
Simulation Models ◽  
Model Choice ◽  
Ecosystem Models ◽  
Distinct Structure ◽  
Ecosystem Effects ◽  
Ecosystem Simulation ◽  
Ecosystem Level

Ecosystem simulation models are valuable tools for strengthening and promoting ecosystem-based fisheries management (EBFM). However, utility of these models in practical fisheries management is often undermined by lack of simple means to test the effect of uncertainty on model outputs. Recently, the use of multiple ecosystem models has been recommended as an ‘insurance’ against effects of uncertainty that comes with modelling complex systems. The assumption is that if models with different structure and formulation give consistent results, then, policy prescriptions are robust (i.e. less sensitive to model choice). However, information on the behaviour of trends from structurally-distinct ecosystem models with respect to changes in fishing conditions is limited, especially for freshwater systems. In this study, we compared outputs of two ecosystem models, Ecopath with Ecosim (EwE) and Atlantis, for Lake Victoria under different fishing pressure scenarios. We compared model behaviour at the ecosystem level, and also at a level of functional groups. At functional group level, we determined two questions: what is the change in the targeted group, and what are the consequent effects in other parts of the system? Overall results suggest that different model formulations can provide similar qualitative predictions (direction of change), especially for targeted groups with similar trophic interactions and adequate data for parameterization and calibration. However, considerable variations in predictions (where models predict opposite trends) may also occur due to inconsistencies in the strength of the aggregate multi-species interactions between species and models, and not necessarily due to model detail and complexity. Therefore, with more information and data, especially on diet, and comparable representation of feeding interactions across models, ecosystem models with distinct structure and formulation can give consistent policy evaluations for most biological groups.

scholarly journals Evaluation of the exploitation of Eastern Baltic cod (Gadus morhua callarias L.) stock in 1976–1997

2003 ◽  
Vol 60 (5) ◽  
pp. 1114-1122 ◽  
Author(s):  
Krzysztof Radtke
Keyword(s):  
Gadus Morhua ◽  
Management Strategies ◽  
Mortality Rates ◽  
Reference Points ◽  
Fishing Mortality ◽  
Safe Level ◽  
Stock Biomass ◽  
Spawning Biomass ◽  
Eastern Baltic ◽  
Baltic Cod

Abstract Big changes occurred in the Eastern Baltic cod biomass and catches in the 1976–1997 period. At present, the Eastern Baltic cod stock spawning biomass (SSB) and catches are approximately five times lower than their highest ever recorded levels observed in the middle of the 1980s. The reasons for the stock decline, namely low recruitment and high fishing mortality, are widely known and well described in the literature. Throughout the whole period, the International Council for the Exploration of the Sea (ICES) made scientific recommendations regarding the exploitation level of the cod stock. The ICES presented and analysed different management strategies based on fishing mortalities which corresponded to biological reference points (BRP) and also recommended total allowable catches (TACs) for cod, taking into account the sustainability of cod resources. In fact, in most years the TAC established by the International Baltic Sea Fisheries Commission (IBSFC) and cod catches (observed exploitation) exceeded the ICES-recommended TAC and thus their scientific advice was neither taken into account by the IBSFC nor by fishermen. This paper evaluates: (1) the would-be state of the Eastern Baltic cod stock if it had been exploited according to ICES-recommended TAC levels, as compared with observed stock exploitation; and (2) the potential effects of management using fishing mortality rates which correspond to BRP on SSB estimates and catch levels, as compared with observed stock exploitation. It is concluded that if ICES advice had been followed, the cumulative cod catches in the 1976–1997 period would have been the same as those observed, but the stock biomass would have been much higher and at a safe level (SSB above 240 000 t). Furthermore, from the comparative analysis of different management strategies based on BRP and the observed strategy, it appears that other management strategies could have been applied which would have produced a higher biomass and greater cumulative catch numbers than those observed.

scholarly journals Fishing for biodiversity

2021 ◽  
Author(s):  
Richard Law ◽  
Michael J Plank
Keyword(s):  
Species Conservation ◽  
Mortality Rates ◽  
Marine Ecosystems ◽  
Single Equation ◽  
Coastal Communities ◽  
Moderate Intensity ◽  
Fishing Mortality ◽  
Production Rates ◽  
Species Production ◽  
First Time

Fisheries are damaging, and seemingly incompatible with the conservation of marine ecosystems. Yet fish are an important source of food, and support the lives of many people in coastal communities. This paper considers an idea that a moderate intensity of fishing, appropriately scaled across species, could help in maintaining biodiversity, rather than reducing it. The scaling comes from an intuition that rates of fishing mortality of species should be kept in line with production rates of the species, a notion known as balanced harvesting. This places species conservation and exploitation on an equal footing in a single equation, showing quantitatively the relative levels of fishing mortality that species of different abundance can support. Using a dynamic model of a fish assemblage, we give numerical evidence showing for the first time that fishing, if scaled in this way, can protect rarer species, while allowing some exploitation of species with greater production. This works because fishing mortality rates, when scaled by production, are density-dependent. Such fishing, operating adaptively to follow species' production rates over time, contains a feedback that would help to protect species from overfishing in the presence of uncertainty about how marine ecosystems work.

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