An overview of the North Sea multispecies modelling work in ICES

Work on multispecies assessment and management has been conducted within ICES (the International Council for the Exploration of the Sea) throughout the 1980s and is still ongoing. The focus has been principally the biological interactions, although there has been an increasing tendency to consider technical interactions too. Most of the work on biological interactions has been carried out by two working groups — the ad hoc Working Group on Multispecies Assessment Methods and the ad hoc Multispecies Assessment Working Group. In this paper, a brief overview of the work of those groups is given, but with emphasis on the latter over the most recent years. The difficulties and problems of the assessment methods are highlighted as well as the progress and successes. The contrast between single-species and multispecies assessments and steady-state forecasts is made and the consequences for management decisions are discussed. It is concluded that, whereas multispecies management approaches might not yet be the all-powerful tools that many people imagine or hope for, they will, with suitable caution and communication, become routine vehicles for investigating fisheries management options.