In the Gulf of Mexico, overfishing of menhaden has contributed to an explosion in the population of jellyfish, which compete with menhaden for food. In the Gulf of Maine, the decline of cod opened the neighborhood to dogfish, small sharks that compete with and sometimes eat cod but aren't as commercially valuable. The federal government delegates most regulatory decisions to eight regional fishery-management councils, made up mainly of representatives from the fishing industry and government, with others from environmental and consumer groups. The result is a crazy-quilt of local regulations that vary enormously in details and success from one region to the next. Supporters of the system say it's fair because decisions are made by the people most directly affected the fishermen themselves.
Critics say the fox is guarding the henhouse.
The National Marine Fisheries Service can overrule fishery-council decisions but does so only rarely, preferring to rely on consensus. In general, the strictest regions have been most successful at curbing overfishing. In Alaska, for example, regulators set annual catch quotas for every species. The season's over for the year. Too often, they don't.