Special request background document: Lemon sole, witch, turbot and brill - Review of ICES advice provided in 2018 on the contribution of TACs to fisheries management and stock conservation. (Ad hoc)

20/01/2023: Table 1.1 - rounding error corrected. Figure 1.1 - figure legend corrected. 

Executive summary

In 2018 the European Commission submitted a Special Request to ICES to investigate the contribution of Total Allowable Catches (TACs) to fisheries management and stock conservation for brill (27.3a47de), turbot (27.4), lemon sole (27.3a47d), witch (27.3a47d) and whiting (27.3a). ICES was requested to analyse the role of the Total Allowable Catch (TAC) instrument and to assess the risks of removing TACs in light of the requirement to ensure that the stock concerned remains within safe biological limits in the short and middle term. 

In 2022 the EU and UK submitted a new request to ICES to investigate whether conclusions from 2018 remain valid, and to update the advice if needed. The request concerns four stocks: brill (27.3a47de), turbot (27.4), lemon sole (27.3a47d) and witch (27.3a47d). It was agreed to answer the request by updating the answers to a series of six questions addressed in the 2018 request. The six questions were as follows:

1. Was the TAC restrictive in the past? 
2. Is there a targeted fishery for the stock or are the species mainly discarded?
3. Is the stock of large economic importance or are the species of high value?
4. How are the most important fisheries for the stock managed?
5. What are the fishing effort and stock trends over time?
6. What maximum effort of the main fleets can be expected under management based on F_MSY (ranges) for the target stocks, and has the stock experienced similar levels of fishing effort before?

This report describes the analysis for brill, turbot, witch flounder and lemon sole first covering each of the above questions, then providing concluding sections.