Comparisons of landings to scientific advice indicate overshooting within the common TAC for skates and rays in the Northeast Atlantic

Abstract

Abstract The International Council for the Exploration of the Sea (ICES) typically provides advice on fishing opportunities on a stock-by-stock basis. Nevertheless, levels of total allowable catch (TAC) are sometimes set for a collection of stocks and species (i.e. a common TAC). An explicit expectation of these is that landings will scale with ICES advice, especially when ICES advice is used to calculate the common TAC. This expectation is tested for skates and rays in the Northeast Atlantic, spanning 26 stocks, 8 species, and 3 ecoregions. Using ICES landings and ICES advice data from 2016 to 2022, we show that landings of several stocks and species have overshot their respective ICES advice, whereas others have undershot. Specifically, some stocks of blonde ray (Raja brachyura) in North Sea and Celtic Seas ecoregions are being landed at a rate that often exceeds double its ICES advice. By collating species based on their ICES assessment category and life-history traits, we find that those considered data-poor and potentially most vulnerable to fishing are consistently landed at higher-than-expected rates in the Celtic Seas. This study questions the appropriateness of a common TAC for skates and rays and calls for shifts towards the use of single-stock catch allocations and the application of advanced stock assessment methodologies.