ISSN:
1365-2109
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
Notizen:
Abstract. The paper describes the development and current status of salmon, Salmo salar L., ranching in Iceland, with a special emphasis on recapture techniques and homing to the release sites. Many ranching operations are located at release sites with little or no rearing activity except for a short acclimatization period before release. This technique was a breakthrough in Icelandic ranching development, as most suitable ranching sites do not have suitable conditions for smolt rearing.Ranching is mostly practised on the west coast of Iceland, where ranched salmon made up over 80% of the total catch in 1991. The largest ranching stations are Kollafjördur and Vogavík in south-western Iceland and two stations, Lárós and Silfurlax, located on the outer part of Snæfellsnes. Combined releases in 1991 were about 6 million smolts and 130 thousand salmon were harvested from ranching.Ranched salmon are mostly harvested from June to August with a peak run in July. The methods of recapture vary considerably. At Kollafjördur Fish Farm, which has river water for attraction, the salmon are mostly caught in riverine traps of conventional design, but during periods of draught an estuarine seining process has been practised to secure bright salmon. At Vogavík, which only has pumped well water for attraction, catches have been based on efficient estuarine traps. Similar methods have been used at the Silfurlax operation in Hraunsfjördur.Homing to ranching sites has been shown to be fairly precise, especially if smolts are released in fresh water and suitable ranching stocks are used. There are indications that the Kollafjördur ranching strain, which has been developed over a period of 25 years, has better homing than wild stocks. Considerable straying has been observed, primarily between ranching stations and into the outflows of large land-based salmon farms. Straying into salmon streams seems to vary from year to year and is greatest in the vicinity of large ranching stations. It seems to occur in late summer, possibly as a result of inadequate recapture techniques at the ranching sites.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1365-2109.1994.tb00680.x
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