Strategies for Reducing Risks from Introductions of Aquatic Organisms: A Marine Perspective

Transfers and introductions of marine species have occurred and are occurring on a worldwide basis, largely in response to perceived needs of expanding aquaculture industries. Greatest interest is in salmon (cage rearing and ocean ranching), shrimps, and bivalve mollusks, although other organisms are being considered. Any reduction of risks with respect to species introductions requires effective communication at appropriate levels, adoption of codes of uniform practices (insofar as national capabilities permit), and attempts at international uniformity in inspections and regulations. The North Atlantic nations, functioning through the International Council for the Exploration of the Sea, have made progress in satisfying each of these strategic requirements, and this activity may be taken as a model for other regional and national efforts. A major concern is the introduction of diseases not presently endemic in an area or hydrographic zone. Recent worldwide transfer of a virus pathogen of penaeid shrimps is an excellent example. Negative ecological impacts of introductions of seaweeds have already been seen in the coastal waters of several countries. Because of the virtual irreversibility of successful introductions to marine waters, the problem is particularly acute, and calls for concerted international response. Some strategies to reduce risks from deliberate introductions include the development of governmental awareness of the potential effects of such actions; the establishment of regional and even international committees to discuss problems related to introductions and to develop mutually acceptable procedures; and the inclusion of considerations of introductions on the agendas of international regulatory bodies concerned with living resources.