Report of the Joint ICES-MYFISH Workshop to consider the basis for FMSY ranges for all stocks (WKMSYREF3)
The Joint ICES-MYFISH Workshop to consider the basis for FMSY ranges for all stocks was held at DTU-Aqua, Charlottenlund, Denmark from 17—21 November 2014.
The workshop was convened in response to a request from the European Commission for advice on potential intervals above and below FMSY. The meeting was attended by 14 delegates from 8 countries and 3 representatives of 3 stakeholder organisations, and was chaired by John Simmonds (ICES) and Anna Rindorf (Denmark). The work conducted was centred around six Terms of Reference concerning methods for estimating FMSY ranges, FMSY ranges for North Sea demersal stocks, Baltic Sea stocks, anchovy in Subarea VIII and horse mackerel (Western stock) and guidelines for estimating FMSY ranges for other stocks which are compatible with obtaining no less than 95% of the estimated maximum sustainable yield and which are considered precautionary in implementation.
The methodology used is based mostly on stochastic equilibrium yields that give 95% of yield at FMSY. The approach was to use fixed F exploitation (without F reduced by the ICES HCR MSY Btrigger). The upper limit to F was constrained where necessary by precautionary criteria that there should be <5% probability SSB For stocks assessed with surplus production models provisional intervals been calculated, but currently for the one stock concerned (megrim) it has not been possible to evaluate the precautionary considerations; therefore, the upper end of the MSY interval is limited to FMSY.
For short lived stocks MSY intervals are based on escapement biomass targets and an interval at a lower exploitation rate that delivers 95% of MSY. No increase in exploitation is advised as escapement targets already include precautionary considerations.
MSY intervals are provided for category 1 stocks with age based assessment for the North Sea and Baltic regions. For only a few of these stocks were the upper ends of the F intervals within precautionary limits, and these were all species with L infinity > 60cm.
For stocks where precautionary reference points are not available, MSY intervals are limited to a maximum rate equal to FMSY.
For stocks without MSY targets (category 3, 4, 5 and 6 stocks) it is not possible to provide MSY intervals.
Published under the auspices of the following ICES Steering Group or Committee