The second workshop on lists of commercial fish and shellfish species for reporting of MSFD D3 (WKD3Lists2)

WKD3Lists2 created lists of regionally relevant commercial fish and shellfish species (and higher order taxa) for the use of Article 8 reporting by EU member states under Descriptor 3 of the Marine Strategy Framework Directive (MSFD). The regional taxa lists were based on landings data from the Fisheries Dependent Information data base (FDI) provided by EU member states and compiled by the Joint Research Centre (JRC). The taxonomy of landings data was consolidated by regional experts and the consolidated data were combined to obtain absolute and proportional landing weights and values for each (sub)re-gion, which were used to apply dual (weight and vale) selection thresholds to compile (sub)re-gional D3-taxa-lists. Regional D3-taxa-lists were produced for two MSFD regions (Baltic Sea & Black Sea) and eight MSFD subregions: The Greater North Sea, Celtic Seas, the Bay of Biscay and Iberian Coast, Mac-aronesia, Western Mediterranean, the Ionian Sea & Central Mediterranean, the Adriatic Sea and the Aegean-Levantine Sea. To exclude taxa with very low landing weights or value from the final lists, two types of thresh-olds (cumulative and minimum) with differing cut-off values were evaluated (90%, 95%, 98% and 99% for cumulative and 0.1% and 1% for minimum thresholds). Depending on the cut-off value, the number of taxa included varied substantially and in most (sub)regions the application of thresholds reduced the initial number of taxa by more than 50%. WKD3Lists2 did not recommend any threshold type or cut-off value to be applied generically in all (sub)regions, but identified trade-offs between inclusiveness and parsimony of relevant con-tent i.e. higher cut-off values will lead to longer lists including many taxa with relatively low landings weights/values. In some (sub)regions, thresholds with lower cut-off values (90% to 95%) were considered feasible by regional experts (Mediterranean subregions, Bay of Biscay and Iberian Coast, Macaronesia), whereas in other MSFD (sub)regions cut-off values in the range of 98-99% were considered as appropriate (Baltic Sea, Greater North Sea, Celtic Seas). The regional D3-taxa lists by WKD3Lists2 were created without considering the availability of data or assessments i.e. many species are included, for which no assessment information is avail-able. WKD3Lists2 decided on this approach because a representative selection of commercially targeted taxa was considered to indicate knowledge and data gaps in current data collection and assessment schemes. Regional species lists shall be used by EU member states for the national reporting of D3. Stocks and species from the regional lists shall be considered by member states, and additional stocks/species can be added where appropriate (e.g. those stocks/species of national or local of importance that do not appear on the regional lists). x WKD3Lists2 discussed and compiled recommendations on how Member States can complement the regional lists of D3-taxa. A key recommendation is to maintain taxa reported in 2018 under D3, even if they are not part of the regional D3-taxa list for 2024. Wherever possible, Member States should report on stock level. WKD3Lists2 also discussed linkages between D1 and D3-reporting of commercial taxa.info:eu-repo/semantics/publishedVersio

Population Genetic Study on the European Flounder (<i>Platichthys flesus</i>) from the Southern Baltic Sea Using SNPs and Microsatellite Markers

The European flounder (Platichthys flesus), which is closely related to the recently discovered Baltic flounder (Platichthys solemdali), is currently the third most commercially fished species in the Baltic Sea. According to the available data from the Polish Fisheries Monitoring Center and fishermen’s observations, the body condition indices of the species in the Baltic Sea have declined in recent years. The aim of the present study was to obtain information on the current patterns of genetic variability and the population structure of the European flounder and to verify whether the Baltic flounder is present in the southern Baltic Sea. Moreover, we aimed to verify whether the observed decline in the body condition indices of the species in the Baltic Sea might be associated with adaptive alterations in its gene pool due to increased fishing pressure. For this purpose, 190 fish were collected from four locations along the central coastline of Poland, i.e., Mechelinki, Władysławowo, the Vistula Lagoon in 2018, and the Słupsk Bank in 2020. The fish were morphologically analyzed and then genetically screened by the application of nineteen microsatellite DNA and two diagnostic SNP markers. The examined European flounder specimens displayed a high level of genetic diversity (PIC = 0.832–0.903, I = 2.579–2.768). A lack of significant genetic differentiation (Fst = 0.004, p > 0.05) was observed in all the examined fish, indicating that the European flounder in the sampled area constitutes a single genetic cluster. A significant deficiency in heterozygotes (Fis = 0.093, p Ne) among the sampled fish groups varied from 712 (Słupsk Bank) to 10,115 (Władysławowo and Mechelinki). However, the recorded values of the Garza–Williamson indicator (M = 0.574–0.600) and the lack of significant (p > 0.05) differences in Heq > He under the SMM model did not support the species’ population size changes in the past. The applied SNP markers did not detect the presence of the Baltic flounder among the fish sampled from the studied area. The analysis of an association between biological traits and patterns of genetic diversity did not detect any signs of directional selection or density-dependent adaptive changes in the gene pool of the examined fish that might be caused by increased fishing pressure

Baltic Fisheries Assesment Working Group (WGBFAS)

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Baltic Fisheries Assesment Working Group

The main ToR of WGBFAS is to assess the status and produce a draft advice on fishing opportu-nities for 2024 for the following stocks: • Sole in Division 3.a, SDs 20–24 (Skagerrak and Kattegat, western Baltic Sea; catch advice) • Cod in Kattegat SD 21 (catch advice) • Cod in SDs 22–24 (western Baltic; catch advice) • Cod in SDs 24–32 (eastern Baltic; catch advice) • Herring in SDs 25–27, 28.2, 29 and 32 (central Baltic Sea; catch advice) • Herring in SD 28.1 (Gulf of Riga; catch advice) • Herring in SDs 30-31 (Gulf of Bothnia; catch advice) • Sprat in SDs 22–32 (Baltic Sea; catch advice) • Plaice in SDs 21–23 (Kattegat, Belt Seas, and the Sound; catch advice) • Plaice in SDs 24–32 (Baltic Sea, excluding the Sound and Belt Seas; catch advice) • Brill in SDs 22-32 (Baltic Sea; stock status advice for years 2024, 2025 and 2026) • Dab in SDs 22-32(Baltic Sea; stock status advice for years 2024, 2025 and 2026) The working group fulfilled the ToRs in assessing the stock status and produced draft advice, including, where relevant, forecasts for fishing opportunities for all stocks with one exception. The assessment for cod in SDs22-24 (western Baltic) was downgraded from category 1 to cate-gory 3 due to unreliable F estimates. However, trends in SSB are still considered reliable and are used as basis for the advice. The WG was not requested to produce advice for four flounder stocks in the Baltic Sea (flounder in SD22-23, flounder in SDs 24-25, flounder in SDs 26+28, and flounder in SDs 27, 29-32) and turbot in SDs 22-32). For these stocks, however, data were com-piled and updated, and update assessments were conducted. In the introductory chapter of this report the WG, in agreement with the other ToRs, considers and comments on the ecosystem and fisheries overviews, reviews the progress on benchmark processes, identifies the data needed for next year’s data call with some suggestions for improvements in the data call, and summarizes general and stock-specific research needs. The introduction further summarizes the work of other WGs relevant to WGBFAS, and the assessment methods used. Finally, the introduction presents a brief overview of each stock and reviews the recently published work on ecosystem effects on fish populations in the Baltic Sea. The analytical models used for the stock assessments were SAM, Stock Synthesis (SS) and SPiCT. For most flatfish (data limited stocks), CPUE trends from bottom-trawl surveys were used in the assessment