Stocking and ranching - a general review
Ísaksson, Á. (1989). Stocking and ranching - a general review, in: De Pauw, N. et al. (Ed.) Aquaculture: a biotechnology in progress: volume 1. pp. 455-473
In: De Pauw, N. et al. (1989). Aquaculture: a biotechnology in progress: volume 1. European Aquaculture Society: Bredene. ISBN 90-71625-03-6. 1-592 pp., more
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Document type: Conference paper
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| Abstract |
The paper attempts to classify ranching within the field of aquaculture and distinguish it from enhancement practices on genetical and biological grounds, especially with respect to salmonids. The term ranching is most commonly applied to migratory species but can be expanded to include extensive farming of sedentary species such as molluscs. The paper approaches ranching primarily from an aquaculture standpoint, where selective breeding practices can be used to improve performance. Propagation programs where enhancement of wild fish is the main issue are not covered. A brief historical account of salmon ranching in the Pacific and the Atlantic is given emphasizing the major breakthroughs. The biological principles behind ranching are discussed, primarily homing, which makes salmon the ideal ranching species, even for private enterprises. The possibilities of improving the ranching performance through selective breeding and manipulation of the rearing cycle are given. A successtul zero-smolt program has been in operation with coho salmon in the US and seems to hold promise for other salmonids. The various ecological and political factors constraining ranching are discussed including grazing capacity, conflict with natural stocks, and harvest strategies. Current production of public and private salmon ranching programs in the Pacific and the Atlantic is covered, including the successful programs in Japan, Alaska, Sweden, and Iceland. Finally the ranching of sedentary species is discussed focusing on oyster and mussel culture in Europe during the last 10 years and recent production figures are given. |
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