Fisheries
The damage or destruction of productive coastal resources and fisheries is a nearly universal problem. Coral reefs are destroyed by construction or dredging, pollution, siltation and dynamiting or poisoning for fish. Mangroves are killed off by dredging or filling, or by changing essential patterns of water circulation and salinity. Seagrass beds are dredged or silted over. Modern boats and fishing techniques combined with increased fishing pressure have driven some coastal fisheries resources (such as giant clams, dugongs or manatees, and sea turtles) to extinction in local areas, and left others seriously depleted. Ciguatera fish poisoning has increased with damaging activities in coral reef areas, further reducing useable fish resources. The result has been a steady reduction in the productive potential of coastal fisheries, one of the most important subsistence sources of protein, with a corresponding increase in imports of canned fish and other substitutes.
The establishment of 200 mile exclusive economic zones has brought most of the ocean area of small island developing States under national jurisdictions. The principal concern in these zones at present is the management of the fisheries for highly migratory species, principally tuna, which can only be done on a regional basis.