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Chukotka is a unique region in the Russian Far East where there are no hatcheries and salmon catches are low. Anadyr River chum salmon average approximately 90 % of the total Chukotka salmon catch and abundance in even-numbered years. There are millions of fish that return annually, and in the last...
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| Format: | Text |
| Language: | English |
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1961
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.433.2634 http://www.npafc.org/new/publications/Technical Report/TR8/Khokhlov.pdf |
| Summary: | Chukotka is a unique region in the Russian Far East where there are no hatcheries and salmon catches are low. Anadyr River chum salmon average approximately 90 % of the total Chukotka salmon catch and abundance in even-numbered years. There are millions of fish that return annually, and in the last eight years the annual run of Anadyr chum salmon numbered about 3 million. The share of Anadyr chum within the total chum salmon catch in the Russian Far East from 1971 to 2010 varied from 0.2 to 27.8 % and averaged 9.95%. Anadyr chum salmon spawn in various locations and sometimes individual spawning grounds are located at considerable distances from one another. The large spatial separation of spawning areas initially led researchers to assume the presence of subpopulations, or even separate populations, in the stock structure of Anadyr chum salmon. But recent genetic results have shown the absence of significant distinctions between samples of Anadyr chum salmon from different spawning areas. Thus, for estimations of abundance Anadyr chum salmon are not divided into separate groups. Chum salmon abundance is estimated on the basis of catches by beach seines and observations of fish in index areas in the middle section of the Anadyr River. To examine long-period fluctuations in Anadyr chum salmon abundance, a onehundred year series of annual catch data were smoothed using an un-weighted sliding average. Results show there is a 40- to 50-year fluctuation in abundance of Anadyr chum salmon (Fig. 1). Anadyr chum salmon abundance increased in the 1930s-1940s and again in the 1980s, with annual catches averaging about 5000 tonnes and 4000 tonnes, respectively, during |
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