Report of the Second ICES/HELCOM Workshop on Flatfish in the Baltic Sea (WKFLABA)

• Main Author: ICES (11907872)
• Format: Report
• Language: unknown
• Published: 2012
• Subjects: Fisheries and aquaculture; Baltic Sea (ICES Ecoregion); WKFLABA; CM 2012/ACOM; flatfish; ICES/HELCOM; Turbot
• Online Access: https://doi.org/10.17895/ices.pub.19281578.v1

The conclusions from WKFLABA 2010 concerning population structure was re-viewed and updated. For plaice it was decided to follow the stock structure sug-gested by ICES WKPESTO 2012: one stock in SD24-32 and one in SD 22+23 (+ Kat-tegat). In analogy with this dab was also reduced to two stocks one in SD22+23; and one in SD 24+25. For both plaice and dab it was decided to merge 24W with 24E since there was no information where the border between 24W and 24E is located. For flounder no changes of the stock structure compared to WKFLABA 2010 was made and still five pelagic and six demersal stocks are identified. Information for brill and turbot were still inconclusive and no suggestions for assessment units could be given. At the request of the HELCOM RED LIST project the group was asked to review the threat assessments of flatfishes in the Baltic Sea done by the HELCOM RED LIST Fish and lamprey species expert team. For most of the species concerned by WKFLABA 2012, brill, plaice, flounder and dab the meeting did not object to HELCOM RED LIST conclusions that these species are probably not threatened within the HELCOM area. However, for turbot data indicate that the stocks have decreased at least in part of the Baltic Sea, hence WKFLABA2012 cannot support the HELCOM RED LIST conclusion that turbot as a species is not threatened in the Baltic Sea. A caution was also raised against using BITS data as cpue index both before and after the change in survey design and gear in 2000. The checklist for Baltic Sea species (HELCOM BSEP 130) was presented and the group complemented information on the distribution of flatfishes in the Baltic Sea and gave some general feedback. Maturity data from female plaice, dab, flounder and turbot were analyzed following the recommendation by WKMSSPDF 2012 that maturity status should not be assessed outside of spawning period. Data mainly from BITS 1st quarter surveys were used but since the survey design doesn’t cover turbot distribution (juvenile as well as adults) alternative time series ...