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The Brief Period of Spring Migration, Short Marine Residence, and High Return Rate of a Northern Svalbard Population of Arctic Char
Author(s) -
Gulseth Odd A.,
Nilssen Kjell J.
Publication year - 2000
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(2000)129<0782:tbposm>2.3.co;2
Subject(s) - arctic char , char , fish migration , salvelinus , population , environmental science , residence time (fluid dynamics) , arctic , geography , oceanography , fishery , geology , biology , demography , fish <actinopterygii> , archaeology , coal , geotechnical engineering , trout , sociology
Arctic char Salvelinus alpinus , in the high‐Arctic archipelago of Svalbard, entered the Dieset River (79°10′N) immediately after ice breakup in late June (1991–1993), and within 48 h almost half the migrating population had left the lakes where they spent the winter. The majority of the anadromous char descended into the sea within 3 weeks of the melt. The temporal pattern of emigration was independent of body size. The average residence time at sea of the char was 33.6 d, and the maximum was 56 d. The duration of the seawater sojourn was independent of body size. However, the combined time of downstream migration and marine residence was inversely related to body length in early migrating char. Fish that migrated to the sea early tended to stay there longer. The overall return rate ranged from 33.3% for the smallest (15.1–20 cm) to 75.0% for the largest (45.1–50 cm) char, averaging 51.5%. The average return rate for fish shorter than 25.1 cm (first‐time migrants) was 42.5%. The upstream run started in mid‐July, peaked in August, and was completed by the beginning of September. In contrast to the seaward migration, there was a structured size‐precedence in the upstream run, with the large char entering the river first, followed by char of intermediate size and then the smallest anadromous char. The results indicate insignificant immigration to this high‐Arctic watercourse. The marked local adaptation to the extreme physical conditions restricted these char to a narrow migrational window. Because this is the first comprehensive study on migratory behavior in anadromous Svalbard char, the results are a valuable contribution to fishery science and management of individual populations in the most northern Eurasian area.