Ecology of peripheral fish populations at their northern extremes

点击翻译按钮获取中文摘要

My research addresses questions pertaining to the biodiversity of Arctic fishes. Firstly, I am studying Atlantic cod that inhabit a coastal lake (Ogac Lake) on Frobisher Bay, well beyond the northern extreme of the species' range in Canadian marine waters. This population is of conservation concern, having been assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as Special Concern in 2003. Preliminary genetic analyses suggest that this population is a glacial relict and has remained isolated from its marine counterparts for thousands of years. Interestingly, the genetic diversity of this population is greater than that recorded for any marine fish. Preliminary analyses also suggest that these cod have unique life histories. Unusual life histories may also underlie the extraordinary variation in body morphology characteristic of Arctic char inhabiting Lake Hazen, Ellesmere Island. Here, within the northernmost population of char in the world, individuals express two, possibly three, morphological types. Identifying the ecological and evolutionary basis for this unique aspect of Arctic fish biodiversity is the primary objective of this second aspect of my research. Thirdly, I am studying the ecology and life history of Arctic marine fishes, notably those for which there is no commercial importance and about which we know exceedingly little. I have initiated studies on several species (including sculpins and snailfish) whose southern range extends to Newfoundland and the Gulf of St. Lawrence. Thus, in addition to obtaining fundamentally important, novel information on marine biodiversity in the North, my work allows me to examine the life history adaptations of various species at the extremes of their geographical range, a question of current importance in conservation biology.