Trends in global shared fisheries.

Shared fisheries involve fish that are caught in the marine waters of more than one country, or in the high seas. These fisheries are economically and biologically significant, but a global picture of their importance relative to total world fisheries catch and economic value is lacking. We address this gap by undertaking a global-scale analysis of temporal trends in shared fisheries species catch and landed value from 1950 to 2006. We find that (1) the number of countries participating in shared fisheries has doubled in the past 55 yr; (2) the most commonly targeted shared species have shifted from those that were mainly restricted to the North Atlantic to species that are highly migratory and are distributed throughout the world; (3) countries which account for the highest proportion of global shared fish species catch and landed value tend to be large industrial fishing powers, whereas those which are most reliant on shared fisheries at a national scale are mainly smaller developing countries. Overall, our findings indicate the increasing need to accommodate a greater number and diversity of interests, and also consider equity issues in the management and allocation of internationally shared fishery resources.