Ecology of peripheral fish populations at their northern extremes

我的研究解决了与北极鱼类生物多样性有关的问题。首先，我正在研究居住在弗罗比舍尔湾沿海湖泊(Ogac湖)的大西洋鳕鱼，远远超出了这种物种在加拿大海域活动范围的北部极端。2003年，加拿大濒危野生动物状况委员会(COSEWIC)将这一种群列为特别关注对象，这是一个令人关注的保护问题。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种群隔绝。有趣的是，这个种群的遗传多样性比任何海鱼的记录都要大。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居住在埃尔斯米尔岛哈森湖的北极炭的身体形态特征异常变化的基础。在这里，在世界上最北端的炭疽种群中，个体表现出两种，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这项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，特别是那些对其没有商业意义且我们知之甚少的鱼类。我已经开始了对几个物种(包括雕像和蜗牛鱼)的研究，这些物种的南部活动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重要、新颖的基本信息外，我的工作还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情况，这是当前保护生物学中的一个重要问题。

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.