Report of the Benchmark Workshop on Roundfish Stocks (WKROUND)

• Main Author: ICES (11907872)
• Format: Report
• Language: unknown
• Published: 2013
• Subjects: Fisheries and aquaculture; Celtic Seas (ICES Ecoregion); Greater North Sea (ICES Ecoregion); benchmark workshop; roundfish; WKROUND; CM 2013/ACOM; whiting; haddock; anglerfish; Dogger Bank; Kattegat; Iceland
• Online Access: https://doi.org/10.17895/ices.pub.19282466.v1

The Benchmark Workshop on Roundfish Stocks (WKROUND) chaired by Mike Armstrong (UK) and Jim Berkson (USA), with invited external experts Martin Dorn (USA) and Steve Ralston (USA ) took place from 8-10 February 2013 to develop benchmark assessments for whiting in Subarea IV (North Sea) and Division VIId (Eastern Chan-nel); haddock in Division VIIa (Irish Sea); anglerfish (Lophius piscatorius and L. budegassa) in Division IIIa (Skagerrak and Kattegat) and Subareas IV (North Sea) and VI (west of Scotland); and haddock in Division Va (Iceland). The objectives of the meet-ing were to evaluate the appropriateness of data and methods to determine stock status in relation to existing or proposed new biological reference points, and to investigate methods for short term outlook taking agreed or proposed management plans into account. As part of the benchmark process, a data compilation workshop was carried out from 8 to 10 January at the Marine Institute in Galway, to review and agree the data, parameters and other information to be used in the benchmark assessments, and to consider the quality of data including discards estimates and misreporting of landings. North Sea whiting: WKROUND carried out comparative XSA, SAM and SURBAR assessments on North Sea whiting. The previously noted discrepancy during the first half of the time series between survey trends and population numbers estimated from the catch at age data was again noted. The pre-1990 catch data would need to be reduced by at least 75% for the FLXSA SSB estimates to resemble those from SUR-BAR. This discrepancy is very difficult (if not impossible) to resolve. WKROUND explored the hypothesis that one of the key problems with the assessment of North Sea whiting was an incorrect assumption about stock structure and identity, and recommended the compilation of data sets to explore the performance of assessments of a joint VIa-IVa stock and a stock south of the Dogger Bank. The results would be analysed to test whether the new stock units lead to an improvement in ...