Suchergebnisse

Under the 2013 Reform of the European Union's Common Fisheries Policy (CFP), fisheries management aims to ensure that, within a reasonable time frame, the exploitation of marine biological resources restores and maintains populations of harvested stocks above levels that can produce the maximum sustainable yield (MSY). The CFP also calls for the implementation of an ecosystem-based approach to fisheries management (EBFM). In this paper, we present the concept of maximum sustainable dead biomass (MSDB) and its associated management reference points for fishing mortality and spawning-stock biomass as alternatives to those associated with MSY. The concept of MSDB is illustrated by a dynamic pool production model of a virtual fish stock which takes into account variations in natural mortality (M), fishing mortality (F), and exploitation pattern. Our approach implies a compensatory mechanism whereby survivors may benefit from compensatory density dependence and is implemented through progressive substitution ofMwith F for varying rates of total mortality (Z). We demonstrate that the reference points for fishing mortality and spawning-stock biomass associated with MSDB are less sensitive to increasing compensation ofMwith F than those associated with MSY and more sensitive to changes in selection pattern. MSDB-based reference points, which are consistent with maximum stock productivity, are also associated with lower fishing mortality rates and higher stock biomasses than their MSY-based counterparts. Given that selection pattern can be influenced through fishery input measures (e.g. technical gear measures, decisions on areas, and/or times of fishing), whereas variations of Min response to F are not controllable (indeed poorly understood), that the results of many fish stock assessments are imprecise, that maximum stock productivity corresponds to MSDB and that MSY-based reference points may best be considered as limits, we propose that MSDB-based reference points provide a more appropriate basis for management under an EBFM.

A systematic European Union (EU)-wide data framework for the collection of fisheries data in support of the EU Common Fisheries Policy (CFP) was first implemented in 2002. Since that time, EU data collection regulation has undergone 2 revisions in response to evolving policy needs. The European Commission's Joint Research Centre (JRC) is responsible for conducting research and providing advice on fisheries management under the CFP, and since 2005 has worked closely with the Scientific, Technical and Economic Committee for Fisheries (STECF). JRC and STECF have an open data policy, and aggregated data submitted by EU member states in response to data calls issued under the provisions of the data collection regulation are published via the website of the STECF. This paper provides an overview of the fisheries data activities carried out by the JRC in support of and in collaboration with the STECF and discusses some of the benefits and drawbacks of such activities.