Combined effects of natural and anthropogenic stressors in fish

鱼在环境中会受到各种各样的压力。像其他变温动物一样，它们的体内温度反映环境温度，因此会随季节波动。鱼类也暴露在工业、城市和农业排放的污染物中。金属是一种特殊的污染物，因为它们也自然存在于环境中，其中有几种，如铁或铜，是生命所必需的。然而，镉等其他金属是非必需的，所有金属，无论是否必需，浓度高时都会有毒。这项研究计划旨在研究温度变化和金属接触对鱼类状况和健康的综合影响。我们将研究高温引起的应力是否会增加它们对金属污染的敏感性，反之亦然。该计划还调查了几种加拿大淡水鱼对这些压力源的耐受极限。

Fish are exposed to a variety of stressors in their environment. Like other ectotherms, their internal temperature reflects environmental temperature and hence fluctuates seasonally. Fish are also exposed to contaminants released by industry, cities and agriculture. Metals are a peculiar type of contaminants, because they are also naturally present in the environment and several of them, like iron or copper, are essential for life. However, other metals like cadmium are non-essential, and all metals, essential or not, become toxic at high concentrations. This research program aims at examining the combined effects of variations in temperature and metal exposure on fish condition and health. We will investigate whether the stress induced by elevated temperatures increases their sensitivity to metal contamination, and vice-versa. The program also investigates the limits of tolerance to these stressors for several species of Canadian freshwater fish.