Implementing the precautionary approach into fisheries management: Biomass reference points and uncertainty buffers

2021 ◽  
Author(s):  
Tobias K. Mildenberger ◽  
Casper W. Berg ◽  
Alexandros Kokkalis ◽  
Adrian R. Hordyk ◽  
Chantel Wetzel ◽  
...  
2007 ◽  
Vol 64 (4) ◽  
pp. 738-743 ◽  
Author(s):  
Kjellrun Hiis Hauge ◽  
Kåre Nolde Nielsen ◽  
Knut Korsbrekke

Abstract Hauge, K. H., Nielsen, K. N., and Korsbrekke, K. 2007. Limits to transparency—exploring conceptual and operational aspects of the ICES framework for providing precautionary fisheries management advice. – ICES Journal of Marine Science, 64: 738–743. ICES precautionary approach to fisheries management advice is based on limit reference points (LRPs) reflecting stock status and precautionary reference points (PRPs) reflecting risk levels. As LRPs are exclusively science-based, while PRPs are management-based, this framework is deployed towards satisfying the ideal of a clear division of science and management's responsibilities. We discuss the variety of technical definitions of reference points and their use in the advisory process. There are inconsistencies in the use of reference points and a tendency to downplay uncertainty. Although the framework can be improved, we argue that some dilemmas will remain. First, transparency of uncertainty presupposes a simple and understandable framework. However, translation of the complexity of natural and human interactions into simple concepts leads to problematic standardization. Second, a clear-cut division of responsibility between science and management is not feasible because LRPs cannot be purely science-based and PRPs cannot be purely management-based. Such dilemmas set fundamental limits to what can be expected from the framework in terms of handling and communicating uncertainty. We suggest that comprehensive dialogue between science and management and explicit reflection on their respective roles will prove more effective at enhancing precautionary and transparent advice on fisheries than adhering to the ideal of strict separation.


1996 ◽  
Vol 11 (3) ◽  
pp. 301-332 ◽  
Author(s):  
Grant J. Hewison

AbstractDespite the precautionary approach being only recently applied to the management of international fisheries, it has raised considerable controversy. There are concerns over the precise legal meaning of the precautionary approach. There are also worries that strict application of the approach will be used to shut down some international fisheries. Moreover, there is continuing debate about how precaution should be applied to the management of fisheries where there has always been, and probably always will be, sparse scientific knowledge. Much of the demand for a precautionary approach to international fisheries management has come from environmentalists, but there has been little analysis of their views. This article seeks to explore the precautionary approach to fisheries management from an environmental perspective. The first part of the article discusses the status of the precautionary approach at international law and, in particular, addresses the question whether the approach has become founded in customary international law. The second part of the article provides an environmental perspective of the precautionary approach and its application to international fisheries. This part covers issues such as the demand by environmentalists for science-based management procedures, the setting of stock levels, anticipatory reference points, ecological safeguards and participation in decision-making.


1998 ◽  
Vol 55 (6) ◽  
pp. 1545-1552 ◽  
Author(s):  
Laura J Richards ◽  
Jean-Jacques Maguire

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.


2020 ◽  
Author(s):  
Tobias K. Mildenberger ◽  
Casper W. Berg ◽  
Alexandros Kokkalis ◽  
Adrian R. Hordyk ◽  
Chantel Wetzel ◽  
...  

AbstractThe precautionary approach to fisheries management advocates for risk-averse management strategies that include biological reference points as well as decision rules and account for scientific uncertainty. In this regard, two approaches have been recommended: (i) harvest control rules (HCRs) with threshold reference points to safeguard against low stock biomass, and (ii) the P* method, a ‘probability-based HCR’ that reduces the catch limit as a function of scientific uncertainty (i.e. process, model, and observation uncertainty). This study compares the effectiveness of these precautionary approaches in recovering over-exploited fish stocks with various life-history traits and under a wide range of levels of scientific uncertainty. We use management strategy evaluation based on a stochastic, age-based operating model with quarterly time steps and a stochastic surplus production model. The results show that the most effective HCR includes both a biomass threshold as well as the P* method, and leads to high and stable long-term yield with a decreased risk of low stock biomass. For highly dynamics stocks, management strategies that aim for higher biomass targets than the traditionally used BMSY result in higher long-term yield. This study makes the case for probability-based HCRs by demonstrating their benefit over deterministic HCRs and provides a list of recommendations regarding their definition and implementation.


1987 ◽  
Vol 44 (4) ◽  
pp. 913-918 ◽  
Author(s):  
M. P. Sissenwine ◽  
J. G. Shepherd

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.


2002 ◽  
Vol 59 (9) ◽  
pp. 1429-1440 ◽  
Author(s):  
Jason S Link ◽  
Jon K.T Brodziak ◽  
Steve F Edwards ◽  
William J Overholtz ◽  
David Mountain ◽  
...  

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.


2019 ◽  
Vol 76 (7) ◽  
pp. 2045-2059 ◽  
Author(s):  
Chuanbo Guo ◽  
Caihong Fu ◽  
Robyn E Forrest ◽  
Norm Olsen ◽  
Huizhu Liu ◽  
...  

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.


2015 ◽  
Vol 27 (4) ◽  
pp. 333-340 ◽  
Author(s):  
Stuart Hanchet ◽  
Keith Sainsbury ◽  
Doug Butterworth ◽  
Chris Darby ◽  
Viacheslav Bizikov ◽  
...  

AbstractSeveral recent papers have criticized the scientific robustness of the fisheries management system used by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), including that for Ross Sea toothfish. Here we present a response from the wider CCAMLR community to address concerns and to correct some apparent misconceptions about how CCAMLR acts to promote conservation whilst allowing safe exploitation in all of its fisheries. A key aspect of CCAMLR’s approach is its adaptive feedback nature; regular monitoring and analysis allows for adjustments to be made, as necessary, to provide a robust management system despite the statistical uncertainties inherent in any single assessment. Within the Ross Sea, application of CCAMLR’s precautionary approach has allowed the toothfish fishery to develop in a steady fashion with an associated accumulation of data and greater scientific understanding. Regular stock assessments of the fishery have been carried out since 2005, and the 2013 stock assessment estimated current spawning stock biomass to be at 75% of the pre-exploitation level. There will always be additional uncertainties which need to be addressed, but where information is lacking the CCAMLR approach to management ensures exploitation rates are at a level commensurate with a precautionary approach.


2011 ◽  
Vol 68 (1) ◽  
pp. 122-136 ◽  
Author(s):  
Yi-Jay Chang ◽  
Chi-Lu Sun ◽  
Yong Chen ◽  
Yuying Zhang ◽  
Su-Zan Yeh

One of the most challenging issues in fisheries management is the evaluation of the effects of fishing in the context of a changing environment. Using the pronghorn spiny lobster ( Panulirus penicillatus ) fishery off the eastern coast of Taiwan as an example, we developed an individual-based model (IBM) that is capable of describing the temperature-dependent life history processes and fishery practices for the spiny lobster. We then used the model to evaluate potential impacts of increased ocean temperature on the estimation of mortality-based biological reference points for fisheries management. We demonstrate that a warming temperature would increase the yield-per-recruit and eggs-per-recruit values and consequently reduce the risk of overexploitation under the current exploitation level. However, there is likely a high risk of overexploitation in the long term if higher temperatures induce extra-high natural mortality. The evaluation of effectiveness of size regulations suggests that increasing minimum legal size is proposed as a good candidate measure to reduce the risk of overexploitation for pessimistically unfavorable environmental conditions. This study suggests that an explicit incorporation of the relationships between environmental variables and biological processes can greatly improve fisheries assessment and management.


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