Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
Sci Total Environ. 2012 Sep 1;433:309-17. doi: 10.1016/j.scitotenv.2012.06.055. Epub 2012 Jul 20.
A snapshot sample of Arctic charr (Salvelinus alpinus) from Heintzelman Lake (81°42'N, 66°56'W), Ellesmere Island, Canada was used to elucidate the biological and life-history factors potentially influencing individual total mercury (THg) concentrations. Migratory history was significant, with anadromous fish having a lower mean THg concentration (64 μg/kg ww) than the non-anadromous Arctic charr (117 μg/kg ww). The increase in individual THg concentration with age was shown to be independent of length-at-age when large and small individuals within the same age groups were compared. Similarly, the diets of individual Arctic charr were comparable regardless of size, and there was no apparent ontogenetic shift in diet that could explain differences in length-at-age or THg concentration among fast- and slow-growing groups of fish (i.e., fish of the same age but differing sizes). Maturity state was also not related to THg concentration, but appears to be related to differences in length-at-age, with slow-growing fish allocating more energy to reproduction than fast-growing conspecifics. The differences in THg concentration among individual Arctic charr were best explained by fish age. We suggest that the increase in mercury concentration with age can be altered by a shift in diet (e.g., to piscivory) or habitat (e.g., anadromy), but is otherwise unaffected by changes in size or length-at-age.
从加拿大埃尔斯米尔岛海因策尔曼湖（81°42'N，66°56'W）采集的北极红点鲑（Salvelinus alpinus）的样本用于阐明可能影响个体总汞（THg）浓度的生物学和生活史因素。洄游历史是显著的，溯河洄游的鱼类的平均总汞浓度（64μg/kg 湿重）低于非溯河洄游的北极红点鲑（117μg/kg 湿重）。当比较同一年龄组的大个体和小个体时，个体总汞浓度随年龄的增加与体长无关。同样，个体北极红点鲑的饮食无论大小都相似，而且饮食没有明显的发育变化，无法解释生长快和生长慢的鱼类群体（即相同年龄但大小不同的鱼类）之间的体长或总汞浓度差异。成熟状态也与总汞浓度无关，但似乎与体长有关，生长缓慢的鱼类比生长迅速的同种鱼类分配更多的能量用于繁殖。个体北极红点鲑之间的总汞浓度差异最好用鱼类年龄来解释。我们认为，随着年龄的增长，汞浓度的增加可以通过饮食（例如，食鱼性）或栖息地（例如，溯河洄游）的改变来改变，但否则不会受到大小或体长变化的影响。
