Fidelity of Anadromous Arctic Char (Salvelinus alpinus) to Nauyuk Lake, N.W.T., Canada

Abstract

The estimated fidelity of anadromous Arctic char (Salvelinus alpinus) returning to Nauyuk Lake from 1974 to 1978 was low (53%). Seven percent of the fish were absent for 1 or 2 yr before returning. Fidelity was also size dependant. Intermediate-sized fish (35–65 cm) had the highest estimated fidelity, while smaller and larger fish had lower rates. The char leaving Nauyuk Lake each spring were categorized into three groups: postspawning char, char that had been observed returning to Nauyuk Lake at least once, and char that had not shown any fidelity to Nauyuk Lake in the past. The char that had shown fidelity to Nauyuk Lake previously had the highest fidelity rate (75%), while the postspawning char and those that had not shown any previous fidelity to Nauyuk Lake both had a fidelity rate of 45%. The low fidelity of the postspawning char was attributed to a higher mortality rate. Fidelity could not be correlated with the length of time a fish was at sea or when it left Nauyuk Lake in the spring.