Escaped or released fish of nonnative species may establish populations in the wild, displacing native fish or otherwise altering natural ecosystems. And if large numbers of native cultivated species escape or are released, their interbreeding with wild fish may alter the genetic makeup of wild populations in significant, undesirable ways. Special Risks of Coastal Fish Farms Coastal aquaculture operations, particularly in developing countries, can cause social and economic as well as environmental harm. Many large commercial shrimp farms in Asia and Latin America have destroyed coastal mangrove forests to make room for their operations. In Ecuador, for example, one-fifth of the mangrove forests were converted to shrimp ponds between 1979 and 1991.
Mangrove forests are highly productive, species-rich habitats.
They are important spawning grounds for many nearshore fish, and mangrove destruction often results in decreased catches for subsistence fishermen. Shrimp farms do not provide most fishermen alternative employment, since they require little labor. Moreover, they do not provide an alternative food source to fish, since most farmed shrimp are exported. In short, the continued rapid growth of the aquaculture industry raises the challenge of how to reap this industry's benefits while avoiding associated environmental problems. Some answers to this challenge may be found in new technology.