Scoring the status of UK shared and national fish stocks around the time of Brexit

Abstract

A Stock Penalty Scoring (SPS) was developed and used to rank the status of fish stocks in the UK EEZ at the time of Brexit. Most of the stocks had negative scores (of relatively less concern) but 19% had positive scores (of more concern). This latter group included many inshore crab and lobster stocks, often assumed to be fished using low-impact methods. Fisheries managers thus need to urgently address problems of over-exploitation in this sector. Policy makers should also not assume that if stock biomass is slightly above Bmsy.trigger then the stock has been rebuilt to an adequate level consistent with legal obligations. The UK 2020 Fisheries Act states that stocks must be maintained above Bmsy, not Bmsy.trigger. For most UK stocks, fishing should be kept below Fmsy to allow stocks to rebuild which should deliver economic and ecosystem benefits in the medium to longer-term. Of the stocks examined, 43% lacked reference points and could not be ranked using the SPS. Although these stocks only contributed 11% of total landings, they include many of local economic importance, and species of conservation concern. Implementing either regular assessments (e.g. for scallops), developing proxy measures (e.g. for skates and rays), or novel techniques (e.g. eDNA) are urgently required to improve their monitoring. The UK aspires to deliver “world class fisheries management” but this will require adequate resourcing of fisheries science and regular monitoring of progress. The SPS approach may provide an additional useful tool for tracking progress in fisheries management post-Brexit.