Akademik Veri Yönetim Sistemi
Froese R.(Yürütücü), Winker H., Coro G., Demirel N., Tsikliras A., Scarcella G.
Diğer Uluslararası Fon Programları, 2016 - 2016
Stock assessments are presented for 397 stocks in 14 European ecoregions, from the Barents Sea to theBlack Sea. Surplus production modeling was used to estimate fisheries reference points in a maximumsustainable yield (MSY) framework. Fishing pressure and biomass were estimated from 2000 to the lastyear with available data (2013-2015). Results are presented by ecoregion and by main functional groups(benthic fish & invertebrates, large predators, pelagic plankton feeders). Cumulative biomass of exploitedspecies was well below the level that can produce MSY in all ecoregions. Fishing pressure has decreasedin some ecoregions but not in others. Barents Sea and Norwegian Sea have the highest percentage (>60%) of sustainably exploited stocks that are capable of producing MSY and which thus fulfill the goals ofthe Common Fisheries Policy of the European Union. In contrast, in most ecoregions of the Mediterraneanfewer than 20% of the stocks are exploited sustainably or are capable of producing MSY. Especially largepredators have low biomass and were subject to strong overfishing in all ecoregions. In the last year withavailable data, 64% of the 397 stocks were subject to ongoing overfishing and 51% of the stocks wereoutside of safe biological limits, potentially suffering from impaired reproduction. Only 12% of the stocksfulfilled the requirement of the Common Fisheries Policy of Europe as being not subject tooverexploitation and having a biomass above the level that can produce maximum sustainable yields.Biomass in the ecoregions of the Mediterranean and Black Sea was on average less than half (44%) of thelevel that can produce MSY, whereas in the northern ecoregions (Barents Sea to Iberian coastal) biomasswas about ¾ (73%) of that level. Rebuilding of biomass above the MSY level would require only a few yearsin most stocks, depending on the depletion level of the stocks and how far exploitation is reduced belowthe MSY-level during the rebuilding phase. For example, exploitation at half the MSY-level would rebuildmost stocks in the northern ecoregions in 1-5 years whereas in the more depleted Mediterraneanrebuilding of stocks would take 2-7 years.Total catches across all stocks and regions were 8.8 million tonnes whereas the maximum sustainableyield (MSY) was estimated at 15.4 million tonnes. Because of trophic interactions it is not possible toachieve MSY simultaneously for all stocks, but after rebuilding of the stocks and assuming a precautionarytarget of 90% of MSY, substantial increases in catches could be possible. These potential increases differwidely between ecoregions, from 25% in the Baltic Sea to over 200% in some Mediterranean ecoregions.Across all stocks and ecoregions, potential increases in catch of over 50% could be possible.Independent assessments of exploitation status were available for 93 (23%) of the examined stocks. Forthe stocks with different classifications, this study tended to underestimate exploitation.