Ecology of peripheral fish populations at their northern extremes

我的研究涉及有关北极鱼类生物多样性的问题。 首先，我正在研究栖息在弗罗比舍湾沿海湖泊（奥加克湖）的大西洋鳕鱼，它远远超出了加拿大海洋沃茨中该物种分布范围的北方极端。 这一种群受到保护关注，加拿大濒危野生动物状况委员会（COSEWIC）于2003年将其评估为特别关注。 初步的遗传分析表明，这一种群是冰川遗迹，数千年来一直与海洋物种隔离。 有趣的是，这个种群的遗传多样性比任何海洋鱼类都要大。 初步分析还表明，这些鳕鱼有独特的生活史。不寻常的生活史也可能是北极炭栖息在哈岑湖，埃尔斯米尔岛的身体形态特征的非凡变化的基础。 在这里，在世界上最北端的红点鲑种群中，个体表达了两种，可能是三种形态类型。 确定北极鱼类生物多样性这一独特方面的生态和进化基础是我研究的第二个方面的主要目标。 第三，我正在研究北极海洋鱼类的生态和生活史，特别是那些没有商业重要性、我们所知甚少的鱼类。 我已经开始研究几个物种（包括杜父鱼和蜗牛鱼），它们的南部范围延伸到纽芬兰和圣劳伦斯湾。 因此，除了获得关于北方海洋生物多样性的基本重要的新信息外，我的工作使我能够研究各种物种在其地理范围的极端情况下的生活史适应，这是保护生物学中当前重要的问题。

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.