World Salmon Ranching

摘要

World production of salmon has been increasing steadily in the last decade and has exceeded historic high levels in some geographic areas due to ranching. Ranched salmon currently contribute more than 20 percent of the world supply. Japan has the largest salmon ranching industry, and the U.S.S.R. is close behind. The Soviets plan a five-fold increase in their industry by 2000 and are expected to surpass Japan. Alaska and Canada have only recently initiated major salmon ranching programs, but both of these political jurisdictions possess natural resources to support salmon ranching on a scale comparable to the U.S.S.R. Artificial propagation of juvenile salmon for release into oceanic basins grew rapidly through the 1970's, and production is expected to double in the 1980's to at least six billion juveniles by 1990. Industrial salmon ranching occurs in the North Pacific Ocean, Sea of Okhotsk, Sea of Japan and the Baltic Sea. Pilot-scale projects are under evaluation in other oceanic basins in the northern and southern hemispheres. Innovative technology for release and recapture of ranched salmon in saltwater shows promise for long-term growth of industrial ranching and improved quality of ranched fish at harvest. Applications are being found for industrial waste heat and waste from food processing to grow juvenile salmon in hatcheries. Institutional structures for producing and harvesting salmon are in transition from hunting to farming. This transition is expected to improve economic efficiency and reduce problems of managing natural and hatchery stocks of salmon. Opportunities to generate substantially larger world supplies of salmon are emerging, and historic high world levels of harvest which occurred in the late 1930's and were based on natural stocks should be exceeded by the early 1990's due to ranching. Negotiations among salmon-producing nations of the North Pacific rim over allocation of grazing rights for ranched salmon are a likely development.