Stock structure and management structure: an ongoing challenge for ICES

Research during the early years of ICES contributed greatly to the understanding of stock structure of marine finfish and invertebrates. More recently, ICES has been a key player in the evolution of modern fisheries-management approaches. Attention to stock structure, which was a major research theme during the early years of ICES, appears to have given way in recent decades to considerations of consistency in management in support of an increasingly complex system o f monitoring, evaluating, and regulating fisheries. For several stocks, there has been, and remains, a mismatch between population structure and management structure. This mismatch has plagued fisheries science and management - and may have led to changes in stock structure (including erosion of spawning components) of some species. A new emphasis on consideration of biodiversity and a precautionary approach to management is raising the importance of stock-structure consideration, and this represents a substantial research challenge for ICES as it begins its second century.