The Workshop on Stock Identification of North Sea Cod (WKNSCodID) was tasked to review information on the population structure of Atlantic cod (Gadus morhua) in the North Sea and adjacent waters to recommend the most plausible scenario of population structure for stock assessment and fishery management advice. Stock identification involves the delineation of the population structure of fishery resources and is a central theme in fisheries science and management. Developments in molecular biology and chemistry, and advances in image analysis and tagging technologies, have prompted revolutionary changes in many stock identification approaches. Stock identification is developing as an increasingly interdisciplinary field and has become a requisite component of fishery science and management programs performed worldwide by research institutions and government agencies.
The WKNSCodID review considers geographic variation and movements of cod life-stages inferred from genetic analyses, scientific surveys, fishery data, tagging, life-history, distribution of eggs and larvae, otolith microchemistry and shape, and parasites. Based on the review, several population structure scenarios were hypothesized (including the scenario assumed in the current advisory unit), and plausibility of each scenario was evaluated. Practical implications of each scenario, including the derivation of a catch time-series, were considered to form recommendations for benchmark stock assessment workshops. A large body of scientific information is available for identification of cod population structure in the North Sea and adjacent areas, and the workshop participants form a diverse group of experts.
