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Growth and Sex Distribution in an Anadromous Population of Arctic Char in Northern Norway
Author(s) -
Strand Rita,
Heggberget Tor G.
Publication year - 1994
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1994)123<0377:gasdia>2.3.co;2
Subject(s) - arctic char , fish migration , salvelinus , population , arctic , sex ratio , ecology , fishery , watershed , geography , biology , fish <actinopterygii> , demography , trout , machine learning , sociology , computer science
Presmolt Arctic char Salvelinus alpinus in the River Halselva watershed, northern Norway, were analysed with respect to growth and sex distribution. Two main hypotheses were tested: (1) females dominate among the first‐time sea migrants; and (2) age at smoltification depends on presmolt growth rate. Our results showed no significant difference in sex distribution of first‐time migrants. There was a low frequency of early maturing males in the population, and no differences between the sexes with respect to early sexual maturation were observed. The first‐time sea migrants showed a higher presmolt growth rate than the nonmigrating parr in Lake Storvatn, the only lake of the Halselva watershed. Based on both the low frequency of mature pan and the sex ratio in the smolt run, the population of Arctic char in the profundal zone in Lake Storvatn is predominantly anadromous fish. These fish migrate to sea at a greater age than the first‐time migrants observed in the River Halselva and are thus “temporarily” resident. This differs from other northern Arctic char populations, in which permanent freshwater‐resident fish often constitute the predominant part of the population.