Mercury (Hg) is a potent toxin that biomagnifies in aquatic food webs. Large fish generally have higher Hg concentrations than small fish of the same species. However, models predict that fish that grow large faster will have lower Hg concentrations than small, slow‐growing fish owing to somatic growth dilution (SGD). We examined the relationship between Hg concentration and growth rate in fish by means of a large‐scale field experiment. Atlantic salmon Salmo salar fry hatched under uniform initial conditions were released at 18 sites in natural streams, collected after one growing season, and measured with respect to Hg concentration and growth. As expected for Hg accumulation from food, the Hg concentrations in the fish tracked those in their prey. Nonetheless, large, fast‐growing fish had lower Hg concentrations than small, slow‐growing ones, consistent with SGD. While the Hg concentration of the prey accounted for 59% of the explained variation in the Hg concentration in the Atlantic salmon across sites, the salmon growth rate accounted for 38%. A mass‐balance Hg accumulation model shows that such SGD occurs when fast growth is associated with high growth efficiency. Fish growth is tremendously variable and sensitive to anthropogenic impacts, so the SGD of Hg has important implications for fisheries management.

中文翻译：

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快速、高效的生长降低了栖息在溪流中的大西洋鲑鱼的汞浓度。

汞 (Hg) 是一种强效毒素，可在水生食物网中生物放大。大鱼的汞浓度通常高于同类小鱼。然而，模型预测，由于体细胞生长稀释 (SGD)，长得更快的鱼的汞浓度将低于生长缓慢的小鱼。我们通过大规模田间试验研究了汞浓度与鱼类生长速度之间的关系。大西洋鲑鱼大西洋鲑在统一的初始条件下孵化的鱼苗在自然溪流中的 18 个地点被释放，在一个生长季节后收集，并测量汞浓度和生长情况。正如对食物中汞积累的预期一样，鱼体内的汞浓度会追踪猎物体内的汞浓度。尽管如此，大型、快速生长的鱼的汞浓度低于小型、生长缓慢的鱼，这与 SGD 一致。虽然猎物的汞浓度占大西洋鲑鱼不同地点汞浓度解释变异的 59%，但鲑鱼的增长率占 38%。质量平衡汞积累模型表明，当快速生长与高生长效率相关时，就会发生这种 SGD。鱼类的生长变化很大，对人为影响很敏感，