Joint EU-Norway request to ICES on options to revise the long-term management plan for herring in the North Sea
ICES has evaluated the biological precautionary reference points to be Blim= 800 000 t and Bpa = 1 000 000 t. Flim and Fpa are not defined. FMSY (average over ages 2–6) is estimated to be within the range 0.24 to 0.30. The value of Btrigger is conditional on the harvest control rule (HCR) selected.
ICES concludes that all harvest control rule options in the request include precautionary scenarios. Several options are considered to be operational for management of the herring fisheries and could be implemented in a revised North Sea herring long-term management plan.
Some HCR options are suggested based on their performance (yield and interannual variability in yield) and applicability for management. These include option 1 (numbers as in request), which is an updated version of the current management plan with new reference points, and options 3b and 3c, which have the ability quickly to adapt to changes in recruitment and stock biomass. Interannual quota flexibility (request item 5) is a practical solution to facilitate fishery operations and could, therefore, also be considered in the management of these fisheries. However, this feature has only been simulation tested under HCR option 1.
Density-dependent regulatory effects on the stock–recruitment relationship can neither be ruled out nor confirmed.
Published under the auspices of the following ICES Steering Group or Committee