Some Effects of Physiographic and Biotic Factors on the Distribution of Anadromous Arctic Char (<i>Salvelinus Alpinus</i>) in Ungava Bay, Canada

Abstract

Interviews with Inuit hunters and measurements of topographic maps were used to characterize 70 rivers discharging into Ungava Bay in northern Quebec in terms of their ability to sustain runs of anadromous arctic char. Field crews visited 29 of these to verify conclusions and add detail. Anadromous arctic char streams tend to differ from non-char streams in size, gradient and distance to overwintering lakes, but there are no clear distinctions. Shallow boulder-strewn areas with maze-like braided channels were the most common cause of lack of char or problems with fish passage. Inuit hunters reported that low flows in autumn, and associated mortalities among migrating fish, have become increasingly common in recent years. We attribute this, at least in part, to changes in climate and the effect of abundant caribou on vegetation. Both destablize flow regimes and increase the prevalence and severity of problems for fish migrating upstream. There is considerable opportunity for stream management to ease fish passage and increase production of anadromous arctic char. This is fortunate because the rapidly growing Inuit population is increasing the demand for subsistence harvests, expansion of the sports fishery and initiation of commercial fishing.

Key words: anadromous arctic char streams, Ungava Bay, hunters, stream management