Report of the Workshop on management strategy evaluation for the Pandalus in Subdivision 3.a.20 and Division 4.a East fishery (WKPandMSE)

• Main Author: ICES (11907872)
• Format: Report
• Language: unknown
• Published: 2017
• Subjects: Fisheries and aquaculture; Pressures; impacts; conservation; and management; Greater North Sea (ICES Ecoregion); WKPandMSE; CM 2016/ACOM; management strategy evaluation (MSE); pandalus borealis; Bergen; Norway; Søvik; northern shrimp; Pandalus borealis
• Online Access: https://doi.org/10.17895/ices.pub.19284716.v1

To follow up a request from Norway to ICES regarding a new management plan for the northern shrimp stock in Skagerrak and the Norwegian Deep, the Workshop on management strategy evaluation for the Pandalus in Subdivision 3.a.20 and Division 4.a East (WKPANDMSE), chaired by Guldborg Søvik (Norway), met on 23–25 August 2016 in Bergen, Norway. The report was finalized by correspondence. The MSE was conducted using a modified version of the HCS harvest rules simula-tion program. The version HCS16L has a stock model structured by age groups, but with life history and selection modelled depending on length-at-age. All evaluations were made relative to a base case simulation reflecting current stock status and dynamics, as well as current assessment accuracy. Discarding level was assumed to occur as presently. Thirty years were simulated (1000 iterations) and mean values calculated for the last 11 years of the simulation period. Two different recruitment functions were used in the simulations, one representing the recent (since 2008) peri-od of predominantly poor recruitment, and one parameterized over the longer time-series with high recruitment values (1988–2007). This allowed modelling the current situation that management must deal with, as well as confirming results against the historical fishery and giving guidance as to how the fishery might be expected to change if recruitment returns to its previous higher level. For the “historic recruitment” scenario (1988–2007), an F of 0.56 was found (corre-sponding to long-term average yield of 13 200 tonnes), while for the “low recruitment” scenario (2008–2014), an F of 0.32 was found (corresponding to long-term average yield of 6300 tonnes). These FMSY are the highest values consistent with the precautionary principle of having less than a 5% chance of dropping below B lim , implying that point estimates are given (not ranges). The yields are removals from the sea. Discards must be deducted to obtain landings estimates. Historical discards (2009–2014) are believed to be ...