Hatchery and wild production of Pacific salmon in relation to large-scale, natural shifts in the productivity of the marine environment
Authors: Beamish R.J.1; Mahnken C.2; Neville C.M.1
Source: ICES Journal of Marine Science, Volume 54, Number 6, December 1998 , pp. 1200-1215(16)
Publisher: Academic Press
Abstract:
Pacific salmon have been fished extensively for at least a century and artificial production of Pacific salmon has been a management strategy to improve production for almost as long. Hatchery production is considered important because it is commonly believed that the carrying capacity for salmon in the ocean has remained more or less constant and is underutilized as a consequence of limited production of smolts in fresh water. Since the mid-1960s, there has been an increase in hatchery production, partly as a response to a desire to increase catch and partly because of improved hatchery techniques. Since the late 1970s there has been a dramatic increase in the total Pacific salmon catch. The increases in catch are now known to result from a large-scale shift in the productivity of the sub-arctic Pacific and management and enhancement actions. Environmental indices changed about 19891990 and may indicate that the productive regime of the 1980s has ended. This would imply that under natural conditions Pacific salmon abundance would decline. There are no clear indications of what to expect in the new regime, but it is apparent that the massive production of artificially reared Pacific salmon would not be necessary in a less productive regime. Of concern is the impact that the large numbers of artificially reared salmon will have on wild salmon stock levels.
Keywords: hatcheries
Language: English
Document Type: Research article
Affiliations: 1: Fisheries and Oceans Canada, Pacific Biological Station, Hammond Bay Road, Nanaimo, B.C., V9R 5K6, Canada 2: National Marine Fisheries Service, Manchester Marine Experimental Station, Manchester, Washington, 98353, USA

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