The scientific purpose of HAWG includes performing stock assessments on each of its target five herring stocks, four sprat stocks and six sandeel stocks, applying state-of-the-art methodology and the most update data (both scientific indices and catch data as well as other available information) to produce quotas in light of the precautionary approach. The results of stock assessments are used to provide the ICES Advisory Committee (ACOM) with a basis for the annual quota advice. HAWG reviews scientific findings pertaining to herring, sprat and sandeel biology and applies these findings when evaluating the state of the related stocks.
As with all assessment working groups, there is a set of generic Terms of Reference (ToRs), which come from ACOM and form the basis of HAWG's work. Special science-related ToRs are written for a more general scientific audience, including members of other working groups who may be able to use the conclusions of such ToRs. Approaches to HAWG are also dealt with by the group, for example letters sent from the Pelagic Advisory Council. This type of communication with stakeholders is both good and constantly improving.
Despite being one of the oldest and more traditional ICES expert groups, HAWG is both innovative and dynamic.