Herring in divisions 6.a, 7.b and 7.c

The primary objective of this study was to assess the identity of herring stocks in ICES Divisions 6.a, 7.b and 7.c, through genetic analysis, in order to develop genetic profiles of the northern (ICES Division 6.a North) and southern (ICES Divisions 6.a South, 7.b and 7.c) stocks, which could be used to discriminate the two stocks during times of mixing, such as, in the summer acoustic surveys. In addition, body and otolith morphometric methods were developed to test if morphometric methods were also able to discriminate the stocks in these areas. The study comprised an extensive review of the history of the existing stock delineations, comprehensive sampling for both the genetic and morphometric components of the project, genetic marker development, genetic screening of samples, the establishment of a genetic protocol for large scale sample screening, morphometric analyses and comparative analyses of both methods. The study has gained substantial interest from stakeholders and the scientific community, and is to contribute to the more accurate management of this species.