The Dawning of the Age of Aquaculture: Will We Learn from Other Countries' Mistakes?

by Boyce Thorne-Miller

Originally published in The Seattle Post-Intelligencer on 2/21/97.

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This week 3,000 "water farmers," scientists, regulators, economists and environmentalists are meeting in Seattle at the World Aquaculture Society's annual conference. They will be discussing a number of critical issues facing commercial fish and shellfish growers, including new technology, economic competitiveness, and environmental sensitivity. The particular problems of salmon and shrimp aquaculture will be high on the agenda.

Perhaps most important to the Pacific Northwest and the United States in general is the future of our domestic coastal marine aquaculture. Fortunately, up to now, it has developed more slowly here than elsewhere, so we may be able to avoid other countries' mistakes -- mistakes that have led to serious environmental problems. Many believe aquaculture to be the solution to today's overfishing crisis. It is not however, a panacea for collapsing coastal fisheries.

Consider the horror stories. Salmon farming in Canada, for example, has had disastrous environmental consequences. Aquaculture facilities pollute offshore waters with fecal material and food wastes, use wild-caught fish to feed their farmed fish, spread disease to wild fish populations, and release farmed fish into the wild where they compete with, prey upon and interbreed with wild salmon with unpredictable consequences.

Likewise, shrimp farmers in Asia and Central and South America are destroying vast expanses of critical mangrove habitat, spreading disease throughout cultivated and wild shrimp populations, and sometimes depleting wild populations by overharvesting wild post-larvae (baby shrimp) to use as seed in their shrimp farms.

Instead of growing species that are most compatible with local ecosystems or the most practical to culture, most ocean farmers in a region focus upon a single commercial fisheries species that have fetched high prices on the international market. They typically establish identical facilities in near proximity to each other. These "monoculture" practices deplete natural resources and enhances the spread of nutrient pollution and disease.

Salmon farming is a prime example of this myopic mentality. These fish are very active carnivores that live on meal made from wild-caught fish, have narrow temperature, salinity and clean water requirements, severely foul their own "nests," and need medicines and chemicals to control disease. Simple logic would suggest they are a poor choice for animal husbandry.

U.S. aquaculture has been limited for various reasons -- wild-caught fish and shellfish have dominated our domestic market, aquaculture technology is costly, the permit process is byzantine, federal support has been weak, and shoreline property owners generally oppose aquaculture development. Even so, environmental problems also have cropped up here.

For example, last year a Puget Sound monoculture facility accidentally released more than 50,000 Atlantic salmon that now compete with native salmon which are already stressed by other human activities. And even shellfish aquaculture, usually thought to be benign, can be insensitive to the environment. Oyster farmers in Willapa Bay on Washington's southern coast grow an alien oyster species which has driven out the native Olympic oyster and they repeatedly contaminate the area with pesticides, most recently to fight a marsh grass that was likely introduced by early oyster farmers.

These cases, however, need not be harbingers of the future. Coastal marine aquaculture offers an opportunity to integrate food production with coastal environmental conservation. It has great potential if approached in a way that makes sense from both agricultural and ecological perspectives.

To soften the impact of any one species on the environment and protect both commercial fisheries and the aquaculture industry from severe loss due to disease and other factors, it is crucial that ocean farmers grow a variety of native species suitable for cultivation. Regional diversification and polyculture, which incorporates a variety of plants and animals, can provide profitable products, live feed, and clean water.

The coastal zone and the valuable resources and services it provides are critical to the people of this country. Coastal aquaculture should therefore be well integrated into healthy coastal ecosystems and should benefit local coastal communities. In addition to providing marketable food, aquaculture should maintain and restore water quality and species diversity.

The commercial interests of private industry should be protected, but so should the needs of tourism, fishing, recreation, and environmental quality control. The U.S. aquaculture industry has been clamoring for fewer government restrictions and a streamlined permit process, and they recoil at the mention of zoning. But deregulation is not the answer. We need zoning, regulations, and incentives to promote locally diverse aquaculture that is economically viable in the context of the coastal zone as a whole. We can develop a vibrant coastal aquaculture and protect the environment at the same time.