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Heavy Exploitation of a Dense Resident Population of Arctic Char in a Mountain Lake in Central Norway
Author(s) -
Langeland Arnfinn
Publication year - 1986
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1577/1548-8659(1986)6<519:heoadr>2.0.co;2
Subject(s) - char , arctic char , arctic , population , geography , environmental science , physical geography , geology , oceanography , fishery , archaeology , biology , demography , coal , trout , sociology , fish <actinopterygii> , salvelinus
During a period of 6 years (1979‐1984), heavy exploitation of a dense resident population of Arctic char (Salvelinus alpinus) was carried out with gill nets in Lake Øvre Stavåtjønn, a small mountain lake in central Norway. The estimated density in 1979 was 1,100 Arctic char (71 kg) per hectare. The total annual yield decreased consistently from 18.0 kg/hectare in 1979 to 3.0 kg/hectare in 1984. This high fishing mortality greatly influenced the population structure, turnover (production‐to‐biomass ratio), age composition, growth rate, and length‐frequency distributions. The yield of Arctic char that weighed over 125 g was greatly increased from 1979 to 1984. According to the Graham model, the maximum sustainable annual yield should be 7 kg/hectare, a reasonable estimate of annual surplus production that could be harvested in the lake under constant exploitation.