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Published byGerald Gordon Modified over 9 years ago
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MEDITERRANEAN SWORDFISH SCI-020
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Background Unique genetic stock Some mixing with the N. Atlantic one Different biological characteristics than the Atlantic stocks Last assessment few weeks ago.
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Fishery Catches around 12000-16000 t in the last decade. 14000 t in 2005. Incomplete information for 2006. Gears: Longlines & Gillnets
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Catch composition Large catches of juveniles (50-70%) SWO Figure 4 Proportion of catch numbers at age by year.
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Stock assessment Two assessment types Production modelling (long data series) Age based VPAs (short data series) } Stock decline
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State of the stocks Production modeling Current stock level about 13% lower than optimum Current F about 25% higher than optimum VPA 40% reduction in spawning stock level but modest changes in the last decade Stable recruitment over the past 20 years. Current spawning stock level half than optimum Current F double than optimum Y/R
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Current (2005) stock status Prod. Mod. median VPA median
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Time trends Production modeling VPA
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Projections VPA Production modeling
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Assessment conclusions The stock is below the level which can support MSY Current fishing mortality exceeds FMSY. The degree to which biomass is below B MSY and F is above F MSY differs between assessment models. Fishing pressure needs to be reduced to move the stock towards to biomass levels which could support MSY and away from levels which could result in non-negligible risks of rapid stock decline; although such worrying signals have not been seen so far in the fisheries.
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Maximum Sustainable Yield14,250-15,500 1 Current (2005) Yield 2 14,600 t Current (2007) Replacement Yield~12,000-14,000 t 1 Relative Biomass (B 2005 /B MSY )0.26-0.87 1 Relative Fishing Mortality F 2005 /F MSY F 2005 /F MAX F 2005 /F 0.1 F 2005 /F 20%SPR F 2005 /F 30%SPR 1.3 (0.6-2.5) 3 2.9 (2.4->5) 4 4.6 (3.7->5) 4 3.0 (2.6->5) 4 4.2 (3.6->5) 4 Management measures in effectNo ICCAT regulations; national closed areas, minimum size and effort controls. Mediterranean Swordfish Summary
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Exploitation scenarios Fishery closures during recruitment
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Management recommendations Adoption of a management plan with the goal of rebuilding the stock to levels that are consistent with the ICCAT Convention objective. Technical measures, such as fishery closures and gear modifications, as well as capacity reductions should be considered in the frames of a management plan
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