scholarly journals Delineating the continuum of marine ecosystem-based management: a US fisheries reference point perspective

2015 ◽  
Vol 73 (4) ◽  
pp. 1042-1050 ◽  
Author(s):  
Tara E. Dolan ◽  
Wesley S. Patrick ◽  
Jason S. Link
Keyword(s):  
Fisheries Management ◽  
Ecosystem Management ◽  
Reference Point ◽  
Marine Ecosystem ◽  
Single Species ◽  
Reference Points ◽  
Current State ◽  
Definition Of ◽  
Compare And Contrast ◽  
The Continuum

Abstract Ecosystem management (EM) suffers from linguistic uncertainty surrounding the definition of “EM” and how it can be operationalized. Using fisheries management as an example, we clarify how EM exists in different paradigms along a continuum, starting with a single-species focus and building towards a more systemic and multi-sector perspective. Focusing on the specification of biological and other systemic reference points (SRPs) used in each paradigm and its related regulatory and governance structures, we compare and contrast similarities among these paradigms. We find that although EM is a hierarchical continuum, similar SRPs can be used throughout the continuum, but the scope of these reference points are broader at higher levels of management. This work interprets the current state of the conversation, and may help to clarify the levels of how EM is applied now and how it can be applied in the future, further advancing its implementation.

An Alternative Perspective on Recruitment Overfishing and Biological Reference Points

1987 ◽  
Vol 44 (4) ◽  
pp. 913-918 ◽  
Author(s):  
M. P. Sissenwine ◽  
J. G. Shepherd
Keyword(s):  
Fisheries Management ◽  
Reference Point ◽  
Reference Points ◽  
Fishing Mortality ◽  
Alternative Perspective ◽  
Conventional Models ◽  
Definition Of ◽  
Yield Per Recruit ◽  
Spawning Biomass

Biological reference points are used to guide fisheries management decisions. The reference points most often used are expressed in terms of fishing mortality rate (F). Fmsy relates to the maximization of sustainable yield. In principle, it is a most useful reference point, but in practice it is difficult to estimate. Fmax and F0.1 relate to certain levels of yield per recruit and are easily estimated, but they ignore conservation of the resource. Recruitment overfishing has usually been understood to occur when a population has been fished down to a point where recruitment is substantially reduced or fails. It has not been used as a basis for a biological reference point because the definition is vague and cannot be readily related to fishing mortality. Levels of spawning biomass below which recruitment seems to be reduced have been used, but their determination from available data is usually difficult and controversial. We propose an alternative definition of recruitment overfishing in terms of the level of fishing pressure that reduces the spawning biomass of a year class over its lifetime below the spawning biomass of its parents on average. Conventional models and types of data can be used to determine this level of F, denoted as Frep, which clearly relates to the replacement of spawning biomass and thus to sustainability of a population and yield in the long term.

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 Advancing ecosystem management strategies for the Gulf of Mexico's fisheries resources: implications for the development of a fishery ecosystem plan

2020 ◽  
Vol 96 (4) ◽  
pp. 617-640
Author(s):  
Andrea Dell'Apa ◽  
Joshua P Kilborn ◽  
William J Harford
Keyword(s):  
Fisheries Management ◽  
Ecosystem Management ◽  
Fishery Management ◽  
Planning Process ◽  
Marine Ecosystem ◽  
Management Strategies ◽  
Single Species ◽  
Ecosystem Approach ◽  
Large Marine Ecosystems ◽  
The Us

Recent global improvements to fisheries sustainability have been made through the adoption of more holistic management frameworks, such as the ecosystem approach to fisheries management (EAFM) and ecosystem-based fisheries management (EBFM), and a concurrent transition from a focus on single species or stocks to multispecies and ecosystems. In the US, federal and regional fisheries management encompass multiple layers of comprehensive, ecosystem focused management strategies for living marine resources within its network of large marine ecosystems (LMEs). Here, we provide an overview for the US portion of the Gulf of Mexico large marine ecosystem (GOM-LME) by examining multiple aspects of its fishery management scheme through the lenses of EAFM, EBFM, and the integrated ecosystem assessment (IEA) framework that has been used worldwide to advise, inform, and operationalize ecosystem management. The US-GOM's fishery management and ecosystem community appears to be keeping pace with other US regional efforts. However, more tools like fishery ecosystem plans (FEPs), which are conducive to the effective integration of ecosystem considerations into fishery management processes, are needed to inform and guide the work of regional managers, decision-makers, and stakeholders. Therefore, we propose a structured planning process aimed at advancing the development and implementation of a GOM-FEP, and describe two case studies of EAFM and EBFM applications, respectively, that can help to navigate through our proposed planning process. This work offers strategic guidance and insights to support efforts of regional fishery managers to translate ecosystem management principles, approaches, and objectives into an "action oriented" FEP in the GOM-LME.

scholarly journals Immediate maximum economic yield; a realistic fisheries economic reference point

2009 ◽  
Vol 67 (3) ◽  
pp. 577-582 ◽  
Author(s):  
Jordi Lleonart ◽  
Gorka Merino
Keyword(s):  
Reference Point ◽  
Fishing Effort ◽  
Reference Points ◽  
Economic Rent ◽  
Short Term ◽  
Fishing Season ◽  
Shrimp Fishery ◽  
Maximum Economic Yield ◽  
Nw Mediterranean ◽  
Definition Of

Abstract Lleonart, J., and Merino, G. 2010. Immediate maximum economic yield; a realistic fisheries economic reference point. – ICES Journal of Marine Science, 67: 577–582. Unregulated or poorly managed fisheries tend towards overexploitation, but fisheries rent does not completely dissipate when immediate rent maximization is sought. The principle of immediate economic rent maximization is the basis of the derivation of a classic model and has led to the definition of a relationship in a catch-and-effort diagram termed the dynamic immediate maximum economic yield (DIMEY) curve. For any initial biomass, if the economic rent in the immediate fishing season is maximized, then the fishing effort and catch strategy that follows will be located on the DIMEY curve. The DIMEY curve is not only used for dynamic simulation but also used to identify a new reference point, the immediate maximum economic yield (IMEY), which is proposed as more realistic than the classic open-access solution for unregulated fisheries. IMEY is proposed as an asymptotic outcome for unregulated or poorly managed fisheries when short-term economic objectives drive fleet activities. IMEY properties are described and compared with traditional fisheries reference points in the yield-and-effort diagram. Theoretical conclusions are compared with empirical evidence provided by the red shrimp fishery off Blanes, Spain (NW Mediterranean). Observed catch-and-effort records are plotted and were positively correlated with the DIMEY curve and IMEY.

Using food web model results to inform stock assessment estimates of mortality and production for ecosystem-based fisheries management

2010 ◽  
Vol 67 (9) ◽  
pp. 1490-1506 ◽  
Author(s):  
Sarah K. Gaichas ◽  
Kerim Y. Aydin ◽  
Robert C. Francis
Keyword(s):  
Food Web ◽  
Fisheries Management ◽  
Prey Availability ◽  
Stock Assessment ◽  
Marine Ecosystem ◽  
Single Species ◽  
Balance Model ◽  
Fishing Mortality ◽  
Important Species ◽  
Predation Mortality

Examining food web relationships for commercially important species enhances fisheries management by identifying sources of variability in mortality and production that are not included in standard single-species stock assessments. We use a static mass-balance model to evaluate relationships between species in a large marine ecosystem, the coastal Gulf of Alaska, USA. We focus on food web relationships for four case-study species: Pacific halibut ( Hippoglossus stenolepis ), longnose skate ( Raja rhina ), walleye pollock ( Theragra chalcogramma ), and squids (order Teuthoidea). For each, we present the species’ position within the food web, evaluate fishing mortality relative to predation mortality, and evaluate diet compositions. We find that high trophic level (TL) species, whether commercially valuable (halibut) or incidentally caught (skates), have mortality patterns consistent with single-species assessment assumptions, where fishing mortality dominates natural mortality. However, assessments for commercially valuable (pollock) or incidentally caught (squids) mid-TL species can be enhanced by including food web derived predation information because fishing mortality is small compared with high and variable predation mortality. Finally, we outline food web relationships that suggest how production of species may change with diet composition or prey availability.

Fishery Indicators for Policy Use in the Mediterranean and Black Sea

2015 ◽  
pp. 183-208
Author(s):  
Dimitrios Damalas ◽  
Vassiliki Vassilopoulou ◽  
Maria Pantazi
Keyword(s):  
Fisheries Management ◽  
Legal Status ◽  
Single Species ◽  
Policy Objective ◽  
Policy Makers ◽  
Current State ◽  
Management Processes ◽  
Multiple Pressures ◽  
Development Goals ◽  
The Mediterranean

The pursuit of sustainable fisheries development as a policy objective has become increasingly important in recent years and policy makers are requiring more information on how to measure progress towards sustainable development goals. In order to accomplish an effective fisheries management, the understanding of how a combination of the aforementioned multiple pressures reduce sustainable limits of harvest is considered a necessity. The multi-species and multi-gears nature of the Mediterranean fisheries hampers the implementation of management processes based on single species analyses. Therefore, the development of methods to integrate information of the fishery systems complexity could be proven advantageous. Among the different approaches, the application of indicators consist a valuable tool for tracking changes and monitoring the implementation of relevant policies. By reviewing the current state of Mediterranean fisheries and linking it to the legal status of fisheries management, a broad spectrum of available indicators, useful for policy, were further considered.

On modal grounding, reference points, and subjectification

2005 ◽  
Vol 3 ◽  
pp. 56-77 ◽  
Author(s):  
Bert Cornillie
Keyword(s):  
Reference Point ◽  
Epistemic Modals ◽  
Reference Points ◽  
Epistemic Modality ◽  
Point Function ◽  
Theoretical Underpinning ◽  
Modal Verbs ◽  
Epistemic Modal ◽  
Modal Auxiliaries ◽  
Definition Of

In this paper it is argued that Langacker’s definition of grounding predications is problematic for languages other than English. The idea that in English tense and modal auxiliaries are mutually exclusive grounding elements leads Langacker (1990, 2003) to consider both deontic and epistemic modal auxiliaries as grounding predications, whereas he excludes German modals from being so on the basis of their tense inflection. In this paper I contend that, unlike the deontic modal verbs, and despite their tense marking, Spanish epistemic modals deber ‘must’, poder ‘may’ and tener que ‘have to’ are certainly appropriate for modal grounding due to their reference point function and to the subjectification they undergo. I show that deontic modality is more affected by temporal grounding than epistemic modality. Moreover, the impossibility of inserting an inchoative verb such as ir a ‘to be going to’ corroborates the theoretical underpinning that Spanish epistemic modals effect an epistemic grounding similar to that of the grounding predications in English.

Linking ecosystem processes to communities of practice through commercially fished species in the Gulf of Alaska

2017 ◽  
Vol 74 (7) ◽  
pp. 2024-2033 ◽  
Author(s):  
Stephani G. Zador ◽  
Sarah K. Gaichas ◽  
Stephen Kasperski ◽  
Colette L. Ward ◽  
Rachael E. Blake ◽  
...  
Keyword(s):  
Communities Of Practice ◽  
Fisheries Management ◽  
Species Interactions ◽  
Fishery Management ◽  
Conceptual Models ◽  
Marine Ecosystem ◽  
Single Species ◽  
Gulf Of Alaska ◽  
Human Dimensions ◽  
Data Types

Abstract Marine ecosystems are complex, and there is increasing recognition that environmental, ecological, and human systems are linked inextricably in coastal regions. The purpose of this article was to integrate environmental, ecological and human dimensions information important for fisheries management into a common analytical framework. We then used the framework to examine the linkages between these traditionally separate subject areas. We focused on synthesis of linkages between the Gulf of Alaska marine ecosystem and human communities of practice, defined as different fisheries sectors. Our specific objective was to document the individual directional linkages among environmental, ecological, and human dimensions variables in conceptual models, then build qualitative network models to perform simulation analyses to test how bottom-up and top-down perturbations might propagate through these linkages. We found that it is both possible and beneficial to integrate environmental, ecological, and human dimensions information important for fisheries into a common framework. First, the conceptual models allowed us to synthesize information across a broad array of data types, representing disciplines such as ecology and economics that are more commonly investigated separately, often with distinct methods. Second, the qualitative network analysis demonstrated how ecological signals can propagate to human communities, and how fishery management measures may influence the system. Third, we found that incorporating multi-species interactions changed outcomes because the merged model reversed some of the ecological and human outcomes compared with single species analyses. Overall, we demonstrated the value of linking information from the natural and social sciences to better understand complex social–ecological systems, and the value of incorporating ecosystem-level processes into a traditionally single species management framework. We advocate for conceptual and qualitative network modelling as efficient foundational steps to inform ecosystem-based fisheries management.

scholarly journals Ecosystem-Based Fisheries Management, Commercial Fisheries, Marine Mammals and the 2001 Reykjavik Declaration in the Context of International Law

2002 ◽  
Vol 17 (4) ◽  
pp. 561-595 ◽  
Author(s):  
Erik Jaap Molenaar
Keyword(s):  
Fisheries Management ◽  
Marine Mammals ◽  
Legal Status ◽  
Marine Ecosystem ◽  
Commercial Fisheries ◽  
Positive Effects ◽  
Legal Constraints ◽  
Definition Of ◽  
Ecosystem Based Fisheries Management

AbstractThe current global crisis in marine capture fisheries contrasts sharply with the recovery of some stocks of marine mammals. Eventually this will have to lead to a re-evaluation of the preferential treatment that marine mammals now often enjoy. The widening support for ecosystem-based fisheries management (EBFM) and the growing insight in the interactions between marine mammals and commercial fisheries are expected to influence this evaluation. This article examines the role of marine mammals in the ecosystem with special emphasis on predation on commercial fisheries. Ample attention is devoted to the definition of EBFM, its legal status and issues of implementation. The 2001 Reykjavik Declaration on Responsible Fisheries in the Marine Ecosystem is used for illustration. One of the conclusions is that sufficient scientific research is required to substantiate positive effects that pre-emptive catches of marine mammals would have for (recovering) commercial fisheries. The regulatory objectives and international legal constraints relevant to marine mammals are moreover addressed to determine if the exploitation of marine mammals could be obligatory or "necessary".

scholarly journals An ecosystem approach to mixed fisheries: technical and biological interactions in the Portuguese multi-gear fleet

2015 ◽  
Vol 72 (9) ◽  
pp. 2618-2626 ◽  
Author(s):  
Inês Cardoso ◽  
Teresa Moura ◽  
Hugo Mendes ◽  
Cristina Silva ◽  
Manuela Azevedo
Keyword(s):  
Fisheries Management ◽  
Marine Ecosystem ◽  
Economic Value ◽  
Single Species ◽  
Ecosystem Approach ◽  
Biological Interactions ◽  
Management Measures ◽  
Species Vulnerability ◽  
Catch Composition ◽  
The Impact

Abstract The term “mixed fisheries” refers to fishing activities where more than one species are caught simultaneously and one species may be fished by different gears. Therefore, mixed fisheries present a harder challenge for fisheries management than single-species fisheries and the uncertainty can start at the definition of the target species. In these particular fisheries, we have a large group of species that are caught, being target or not, species with large landing values that are actually not target, and species with a high economic value that can fall in the bycatch category. Although the dynamics of such fisheries is poorly understood, they are known to have a relevant contribution to Portuguese fishers' revenue. The present demand on sustainable fishing activities to ensure marine ecosystem preservation has led towards an ecosystem approach where effort is being made to take into account biological and technical interactions on management measures and advice. In this work, logbooks data of the Portuguese multi-gear fleet were used to identify different fisheries based on catch composition and gears through cluster analysis (CLARA). Two identified fisheries were used to explore the impact of these fishing activities on the ecosystem scale. This approach was achieved by a productivity and susceptibility analysis and through foodweb analysis. The relation between species vulnerability and their functional role in the ecosystem were highlighted. Technical interactions among fishing gears, and species biological interactions, were explored within and among fisheries. We found and illustrated that these interactions go beyond the fleets and fisheries considered in the present work. This approach allows us to identify key elements that can, ultimately, be relevant to an ecosystem-based approach towards mixed fisheries management.

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