AN EVALUATION OF THE PERFORMANCE OF THE KOBE STRATEGY MATRIX: AN EXAMPLE BASED UPON A BIOMASS DYNAMIC ASSESSMENT MODEL

The main management objective of ICCAT is to maintain the populations of tuna and tuna-like fishes at levels which will permit the maximum sustainable catch. Scientific advice designed to meet this objective, in common with other tuna Regional Fisheries Management Organisations' (tRFMO) scientific committees is presented in the form of the Kobe II Strategy Matrix (K2SM). This is essentially a decision table showing the time taken to achieve management objectives (e.g., stock recovery) for different levels of TAC or effort. The role of the K2SM as an important tool to communicate efficiently among all stakeholders and to assist in the decision-making process according to different levels of risk has been recognised.JRC.G.4-Maritime affair

A KOBE STRATEGY MAATRIX BASED UPON PROBABILISTIC REFERENCE POINTS: AN EXAMPLE USING A BIOMASS DYNAMIC ASSESSMENT MODEL

The main management objective of ICCAT is to maintain the populations of tuna and tuna-like fishes at levels which will permit the maximum sustainable catch. Scientific advice designed to meet this objective, in common with other tuna Regional Fisheries Management Organisations (tRFMO) scientific committees, is presented in the form of the Kobe II Strategy Matrix (K2SM). A decision table is given showing the time taken to achieve management objectives (e.g., stock recovery) for different levels of TAC or effort. However, substantial uncertainties still remain in assessments and therefore a key area of research is to show how uncertainty and improvements in information, consistent with the principles of the precautionary approach, can be incorporated into advice, so that for any level of uncertainty there is the same risk of depletion.JRC.G.4-Maritime affair

On the role of visualisation in fisheries management

Environmental change has focused the attention of scientists, policy makers and the wider public on the uncertainty inherent in interactions between people and the environment. Governance in fisheries is required to involve stakeholder participation and to be more inclusive in its remit, which is no longer limited to ensuring a maximum sustainable yield from a single stock but considers species and habitat interactions, as well as social and economic issues. The increase in scope, complexity and awareness of uncertainty in fisheries management has brought methodological and institutional changes throughout the world. Progress towards comprehensive, explicit and participatory risk management in fisheries depends on effective communication. Graphic design and data visualisation have been underused in fisheries for communicating science to a wider range of stakeholders. In this paper, some of the general aspects of designing visualisations of modelling results are discussed and illustrated with examples from the EU funded MYFISH project. These infographics were tested in stakeholder workshops, and improved through feedback from that process. It is desirable to convey not just modelling results but a sense of how reliable various models are. A survey was developed to judge reliability of different components of fisheries modelling: the quality of data, the quality of knowledge, model validation efforts, and robustness to key uncertainties. The results of these surveys were visualized for ten different models, and presented alongside the main case study.Versión del editor1,86

Limiting inter-annual variation in total allowable catch strategies. An application to ICES roundfish stocks

This study evaluated through simulation management strategy that stabilise catch levels by setting bounds on the inter-annual variability in Total Allowable Catches (TACs). An integrated modelling approach was used, which modelled both the ‘real’ and observed systems and the interactions between all system components. The modelling framework therefore allowed evaluation of the robustness of candidate management strategies to both the intrinsic properties of the systems, and the ability to observe, monitor, assess and control them. Strategies were evaluated in terms of level of risk (measured as the probability of spawning stock biomass falling below the biomass limit reference level for the stock) and cumulative yield. The simulation approach used provides a powerful tool for the examination of the performance of candidate management strategies. It has shown that better management is not necessarily going to be achieved by improving the assessement, since even with a perfect assessment (where the simulated working group knew stock status perfectly) stocks may crash at fishing levels that standard stochastic projections would suggest were safe. Also explicitly modelling the assessment process can result in quite different outcomes than those predicted by the simple projection traditionally used by stock assessment working groups. This is because the simple projection assumes that the status of the stock in the current year is known without error and that the target fishing mortality can be achieved without error. However, in practice the assessment is based on last years data and the effect of any management measure on SSB is only manifest, following the implementation of the quota, at the end of the following year. The choice of target and fishing mortality levels and minimum stock levels results from ICES interpretation of the precautionary approach. This lead to the definition of fishing mortality and biomass reference points that are intended to prevent over-fishing and to trigger recovery plans when a stock is overfished respectively. Although, fishing mortality and biomass reference points were originally intended to be independent, a fishing mortality level implies a corresponding biomass level. In the case of saithe a fishing mortality of 0.40 (i.e. the FPA level) would drive the stock to Blim, suggesting that the choice of biomass and target reference points are not consistent for this stock

Limiting inter-annual variation in total allowable catch strategies. An application to ICES roundfish stocks

This study evaluated through simulation management strategy that stabilise catch levels by setting bounds on the inter-annual variability in Total Allowable Catches (TACs). An integrated modelling approach was used, which modelled both the ‘real’ and observed systems and the interactions between all system components. The modelling framework therefore allowed evaluation of the robustness of candidate management strategies to both the intrinsic properties of the systems, and the ability to observe, monitor, assess and control them. Strategies were evaluated in terms of level of risk (measured as the probability of spawning stock biomass falling below the biomass limit reference level for the stock) and cumulative yield. The simulation approach used provides a powerful tool for the examination of the performance of candidate management strategies. It has shown that better management is not necessarily going to be achieved by improving the assessement, since even with a perfect assessment (where the simulated working group knew stock status perfectly) stocks may crash at fishing levels that standard stochastic projections would suggest were safe. Also explicitly modelling the assessment process can result in quite different outcomes than those predicted by the simple projection traditionally used by stock assessment working groups. This is because the simple projection assumes that the status of the stock in the current year is known without error and that the target fishing mortality can be achieved without error. However, in practice the assessment is based on last years data and the effect of any management measure on SSB is only manifest, following the implementation of the quota, at the end of the following year. The choice of target and fishing mortality levels and minimum stock levels results from ICES interpretation of the precautionary approach. This lead to the definition of fishing mortality and biomass reference points that are intended to prevent over-fishing and to trigger recovery plans when a stock is overfished respectively. Although, fishing mortality and biomass reference points were originally intended to be independent, a fishing mortality level implies a corresponding biomass level. In the case of saithe a fishing mortality of 0.40 (i.e. the FPA level) would drive the stock to Blim, suggesting that the choice of biomass and target reference points are not consistent for this stock

WORKSHOP ON GUIDELINES FOR MANAGEMENT STRATEGY EVALUATIONS (WKGMSE2)

The purpose of the meeting was to bring up to date the methodologies and technical specifications that should be incorporated in Management Strategy Evaluation (MSE) work in ICES. The workshop was tasked with reviewing recent methodological and practical MSE work conducted in ICES and around the world, as well as the guidelines provided by the 2013 ICES Workshop on Guidelines for Management Strategy Evaluations (WKGMSE). The Terms of Reference indicated that the revision should include all aspects involved in MSE, while paying specific attention to several issues that had been identified through ICES practice. The Terms of Reference also requested WKGMSE 2 to consider how best to disseminate the guidelines to experts within the ICES community and the need for training courses. The workshop addressed all its Terms of Reference. The main results of the workshop are the revised MSE guidelines, as well as recommendations in relation to the ICES criterion for defining a management strategy as precautionary and in relation to the evaluation and advice on rebuilding strategies.publishedVersio

Ten lessons on the resilience of the EU common fisheries policy towards climate change and fuel efficiency - A call for adaptive, flexible and well-informed fisheries management

To effectively future-proof the management of the European Union fishing fleets we have explored a suite of case studies encompassing the northeast and tropical Atlantic, the Mediterranean, Baltic and Black Seas. This study shows that European Union (EU) fisheries are likely resilient to climate-driven short-term stresses, but may be negatively impacted by long-term trends in climate change. However, fisheries' long-term stock resilience can be improved (and therefore be more resilient to increasing changes in climate) by adopting robust and adaptive fisheries management, provided such measures are based on sound scientific advice which includes uncertainty. Such management requires regular updates of biological reference points. Such updates will delineate safe biological limits for exploitation, providing both high long-term yields with reduced risk of stock collapse when affected by short-term stresses, and enhanced compliance with advice to avoid higher than intended fishing mortality. However, high resilience of the exploited ecosystem does not necessarily lead to the resilience of the economy of EU fisheries from suffering shocks associated with reduced yields, neither to a reduced carbon footprint if fuel use increases from lower stock abundances. Fuel consumption is impacted by stock development, but also by changes in vessel and gear technologies, as well as fishing techniques. In this respect, energy-efficient fishing technologies already exist within the EU, though implementing them would require improving the uptake of innovations and demonstrating to stakeholders the potential for both reduced fuel costs and increased catch rates. A transition towards reducing fuel consumption and costs would need to be supported by the setup of EU regulatory instruments. Overall, to effectively manage EU fisheries within a changing climate, flexible, adaptive, well-informed and well-enforced management is needed, with incentives provided for innovations and ocean literacy to cope with the changing conditions, while also reducing the dependency of the capture fishing industry on fossil fuels. To support such management, we provide 10 lessons to characterize 'win-win' fishing strategies for the European Union, which develop leverages in which fishing effort deployed corresponds to Maximum Sustainable Yield targets and Common Fisheries Policy minimal effects objectives. In these strategies, higher catch is obtained in the long run, less fuel is spent to attain the catch, and the fisheries have a higher resistance and resilience to shock and long-term factors to face climate-induced stresses

Assessment for All initiative(a4a) - Workshop on development of MSE algorithms with R/FLR/a4a

The a4a approach to Management Strategies Evaluation ( MSE ) is to develop a set of common methods and procedures to build a minimal standard MSE algorithm. This has the most common elements of both uncertainty and management options. Such a tool set should allow for the development of MSE simulations for many fisheries in an operational time frame. Between the 30th of January and the 3rd of February, in Ispra, Italy, the JRC organized a workshop on development of MSE algorithms with R/FLR/a4a. The workshop was a mix of hands-on coding and discussion/implementation of concepts associated with MSEs. The participants used the most recent version of the a4a MSE code, modularized the most important processes and developed their own version of several processes so that the MSE could model and test alternative management procedures to the one initially coded.JRC.D.2-Water and Marine Resource

An evaluation of changes in stock productivity and consequences for management. An example based on North Atlantic albacore Thunnus alalunga

Reference points are important elements of fisheries management and the supporting scientific advisory frameworks. However, fish stocks can fluctuate extensively over a large range of spatial and temporal scales independent of human exploitation and there has been a classical tendency to assume a dichotomy, i.e., that changes in fish populations are primarily attributable either to exploitation or to environmental variability. Therefore we look at variability in surplus production and examine the relative impacts of the environment and exploitation on the productivity of North Atlantic albacore (Thunnus alalunga). The analysis revealed that variations were driven by environmental effects. It was also found that substantial variations in time-series of biomass and catch could be expected even under a constant F equal to FMSY.Les points de référence sont des éléments importants de la gestion des pêcheries et des cadres consultatifs scientifiques d’appui. Toutefois, les stocks de poissons peuvent grandement fluctuer sur de vastes échelles spatio-temporelles indépendantes de l'exploitation humaine et il existe une tendance classique visant à postuler une dichotomie, c’est-à-dire que des changements dans les populations de poissons sont essentiellement attribuables soit à la variabilité de l’exploitation, soit à la variabilité environnementale. C’est pourquoi nous étudions la variabilité dans la production excédentaire et examinons les impacts relatifs de l’environnement et de l’exploitation sur la productivité du germon de l’Atlantique Nord (Thunnus alalunga). L’analyse a révélé que les variations ont été causées par des effets environnementaux. On a également découvert que des variations considérables dans les séries temporelles de la biomasse et de la capture pouvaient être escomptées même avec un F constant égal à FPME.Los puntos de referencia son elementos importantes de la ordenación pesquera y de los marcos de trabajo de asesoramiento científico que los respaldan. Sin embargo, los stocks de peces pueden fluctuar enormemente entre un amplio rango de escalas espaciales y temporales independientes de la explotación humana y ha existido la tendencia clásica a asumir una dicotomía, es decir, que los cambios en las poblaciones de peces se deben principalmente bien a la explotación o bien a la variabilidad medioambiental. Por lo tanto, examinamos la variabilidad en la producción excedente y los impactos relativos del medio ambiente y la explotación sobre la productividad del atún blanco del Atlántico norte (Thunnus alalunga). El análisis reveló que las variaciones estaban motivadas por efectos medioambientales. Asimismo, se descubrió que podían esperarse variaciones sustanciales en la serie temporal de la biomasa y la captura incluso bajo una F constante igual a FRMS