Alaska Salmon Fisheries: A Biological Perspective

Alaska Salmon Fisheries: A Biological Perspective

Pacific salmon are an anadromous species that are born in freshwater, then spend most of their adult life in the sea, and finally come back to the stream where they were born to spawn and die. Alaska has five major salmon species: chinook (king), coho, chum, sockeye, pink, and each is heavily fished. In order to prevent the stocks from decreasing in numbers more than they already have, a few things need to occur. First, Canada and the United States need to decide, together, how many salmon can be taken from the waters each year without affecting the stock for the next year. Second, the problem of salmon being caught as bycatch in the Bering Sea and the Gulf of Alaska needs to be solved. In 1991 alone, 44,000 chum salmon were taken due to the fishing techniques utilized by the groundfish fisheries.

Another problem is the degradation of the habitat in the streams and the wetlands that the salmon spawn in. In order to sustain the salmon fishery, and thus save the state's largest non-governmental source of employment, the habitat must be maintained. The habitat is in integral part of the salmon's existence and the destruction of it will eventually destroy the species. Logging, mining, and industrial and urban development have already affected about 100,000 acres of stream-side habitat where spawning occurs.

In one river, the Kenai, extensive research has been conducted on what habitat destruction does to the spawning efficiency of the salmon that are found there. The U.S Fish and Wildlife Service (USFWS) found that production can not continue from this river if the habitat that supports them is lost. Wetlands, slow moving tributaries, deep pools, graveled river bottoms, bank vegetation, and fast running water are all key elements to the salmon life cycle. They each provide a different item that helps support the requirements the salmon need to grow up (reproduction, food and shelter).

By radio tagging a group of King salmon, researchers discovered what areas were most likely used for each of the three life requirements. They found that spawning usually occurs at the upstream of highly vegetated islands in loose, clean gravel. The salmon tended to stay away from areas that were developed. Because spawning is an essential part of the life cycle, it is clear that the development of the rivers shoreline will cause the salmon not to spawn in ideal places and place the fry in areas of less protection. The juvenile salmon are also generally found in areas where the riverbanks are undisturbed. It is clear that the degradation of the habitat will have a large impact on this river and should not be disturbed any further if we want salmon species to stay at sustainable levels.

The Biological Perspective of fisheries management

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