Cod avoidance techniques for the Dutch and Belgian fishing fleets

Fisheries managers go to great lengths to reduce cod catches in the North Sea, aiming for recovery of the cod stock. The Dutch government asked IMARES to provide an overview of all measures that are in place in various countries around the North Sea for reducing cod catches. The Dutch fisheries managers were specifically interested in the existence of gear adjustments, which might also be applicable in Dutch fisheries. With a complete overview of possible measures, the government, fishing industry and gear scientists can decide together which gear adjustments may be effective and feasible in Dutch fisheries. Whether a gear adjustment is effective, depends on changes in selectivity of the adjusted gear compared to the standard gear. Selectivity depends on the shape and size of fish and on the shape and size of meshes in the cod-end. Also behavioural differences between species determine selectivity. IMARES and ILVO made an inventory of existing gear adjustments for reduction of the cod catch. For a series of gear adjustments we determined the effectiveness and applicability for the Dutch and Belgian fisheries.