Article Abstract:
The number of Atlantic salmon returning each year to spawn in their natal rivers has fallen by over 75% in thirty years. Despite harvest regulation and an almost complete ban on commercial fishing, their numbers continue to decline. Salmon populations in eight rivers in Maine have been classified as endangered by the US Department of Interior. The main cause of the salmon's decline appears to be increased mortality at sea, with possible reasons being diminishing food stocks and exposure of juvenile salmon to the endocrine disruptor nonylphenol. It is hoped that advances in acoustic telemetry will help researchers discover where and when the increased marine mortality occurs.
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Article Abstract:
The Anadromous Atlantic salmon, Salmo salar, is listed as a threatened species in the US but a listing under the Endangered Species Act has been proposed. The National Marine Fisheries Service and Fish and Wildlife Service estimated 79 Atlantic salmon in Ducktrap, Pleasant, Narraguagus, Machias, and Sheepscot Rivers in 1994. Distinct population segments are necessary for anadromous salmonines as their homing behavior forms distinct populations. Species become endangered due to changes in their habitat, overutilization, predation, diseases, and improper existing procedures.
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Article Abstract:
Salmon hatcheries have been established to restore salmon populations on the Columbia River Gorge in Oregon. The project was designed to identify salmon diseases and suggest appropriate treatments, conduct genetic research, preserve strong genetic stock and enhance hatchery rearing practices. The hatcheries were the result of collaboration among several agencies and institutions including the Fish and Wildlife Service, the Lower Columbia River Fish Health Center and the Abernathy Salmon Technology Center.
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