Fisheries

The world's rivers, bays and oceans are now for all practical purposes fully fished, which means that increased harvests trigger declining stocks. 

Despite impressive gains, aquaculture (fish farming) has failed to keep up with world population growth since 1989. The per capita availability of captured and farmed fish is now falling, contributing to rising prices and declining per capita consumption. The future growth of aquaculture is limited by competition for land and water and the growing challenge of keeping farm-raised fish free of disease. While greater efforts to conserve fish stocks are necessary and feasible, population growth rates will remain a major determinant of the prices consumers pay for fish.

The state of the world's fisheries illustrates a collision of human needs and natural resources that is occurring today. By the accounts of experts, the world's oceans and rivers are unlikely to supply more than 60 million metric tons per year of fish as food for human consumption, slightly above current levels. Aquaculture contributes roughly another 16 million tons today, and probably will contribute more in the future. But how much more? To sustain current per capita consumption to the middle of the next century under either the medium or high UN projections for population growth would require fish farmers to supply more food than all the world's oceans, rivers and lakes combined.1 Fisheries experts doubt aquaculture can go much beyond twice its current output, if that. The limitations on suitable land for ponds and pens and dependable water supply, and the difficulties of keeping farmed fish in a state of reasonable health, are simply too great. Over the long term, only a stabilized world population is likely to be compatible with sustainable exploitation of the world's fisheries.