Scientific, Technical and Economic Committee for Fisheries (STECF) :Stock assessments in the Adriatic, Ionian and Aegean seas and strait of Sicily (STECF-23-12)

Commission Decision of 25 February 2016 setting up a Scientific, Technical and Economic Committee for Fisheries, C(2016) 1084, OJ C 74, 26.2.2016, p. 4–10. The Commission may consult the group on any matter relating to marine and fisheries biology, fishing gear technology, fisheries economics, fisheries governance, ecosystem effects of fisheries, aquaculture or similar disciplines This report documents the outcomes of STECF Expert Working Group 23-12: 2023 stock assessments of demersal stocks in the Adriatic, Ionian, Aegean Seas and the Strait of Sicily from the meeting held in hybrid mode from 9th to 15th October 2023. The EWG has been dealing with a total of 17 stocks, including Sardine in GSAs 17 and 18 (PIL 17-18), for which a review of the progress made by the JRC and GFCM benchmark experts in setting up an age based model has been requested, and Giant red shrimp in GSAs 24-25-26-27 (ARS24-27), for which an exploratory analysis of the available data was requested. There were sufficient resources to evaluate all but one of the stocks, Red mullet in GSA 20 (MUT20). Of the remaining 14 stocks (excluding PIL1718 and ARS24-27), Red mullet in GSAs 17-18 (MUT1718) has advice based on biomass indices following ICES category 3 procedures as no assessment is available (GFCM benchmark assessment has to be finalized according to a road map drafted in cooperation with the external reviewers to look for further tests and diagnostics). The remaining 13 stocks have been considered suitable for providing advice on stock status; 8 of these have short term forecasts (STF) using the standard STF projection with assumptions of different F scenarios (e.g. status quo F, Fmsy, Fupper Flower etc) and historic recruitment. For Norway lobster in GSAs17 and 18 (NEP1718) catch projection results have been used to fill in the ad-hoc spreadsheet developed in previous EWG to provide forecast on one year basis. For the 4 stocks without STF, 3 (namely Red mullet in GSA19, Blue and red shrimp in GSAs 18-19-20 and Striped red mullet in GSAs15-16) have been considered not suitable due to instability in the final years of the last assessment (catch projection did not help in stabilizing the model). As these stocks are not under management plans, the assessments are provided as illustrative of stock status, but FMSY forecasts are not available. In these cases, a status quo F forecast is provided to give a general indication of change, the assumptions for this are less demanding than for a specified F change, and the catches are not advised. Finally, for Deep-water rose shrimp in GSAs 17, 18, 19 and 20 (DPS17181920), it was not possible running any forecast because the F target (Fmsy) is estimated on yearly basis according to the model settings agreed in the benchmark depending (re-estimated year by year and so not a reference target in the short/long term; e.g., the 2022 value could be not valid anymore for 2023 or 2024). Due to the lack of Italian survey information for 2022, all the stocks, excluding Common sole in GSA17, European Hake in GSAs 20 and 22 and Red mullet in GSA22, were evaluated through a catch weight projection as already agreed by the EWG23-09 on Western Mediterranean stocks. The methodological approach used is described in the section 4 of the report.