Although the introduction of non‐native fish species has been shown to alter trophic ecology in aquatic ecosystems, there has been limited research on how invasive species alter methylmercury (MeHg) biomagnification in lacustrine food webs. We sampled surface water and biota from 8 lakes in Quebec, Canada, spanning a range of dissolved organic carbon (DOC) concentrations (2.9–8.4 mg/L); 4 lakes were inhabited by native brook trout (Salvelinus fontinalis), and the remaining lakes contained brook trout and a non‐native fish, Allegheny pearl dace (Margariscus margarita). Periphyton, zooplankton, macroinvertebrates, and fish were analyzed for: 1) stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope ratios to delineate food webs, and 2) total Hg (THg) or MeHg. Compared with the brook trout from reference lakes, fish from invaded lakes had higher length‐standardized THg concentrations as well as a narrower dietary range and elevated trophic level, inferred from unadjusted δ¹³C and δ¹⁵N values, respectively. The rate of Hg biomagnification was similar across invaded and reference lakes, implying little effect of the invasive fish on the trophic transfer of MeHg. Despite differences in food web structure due to pearl dace invasion, DOC was the strongest predictor of brook trout THg levels for all lakes, suggesting that underlying environmental factors exerted a stronger influence on brook trout THg concentrations than the presence of a non‐native forage fish. Environ Toxicol Chem 2020;39:2196–2207. © 2020 SETAC

中文翻译：

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非原生鱼对沿溶解有机碳梯度的湖相食物网结构和汞生物放大的影响。

尽管已证明引进非本地鱼类物种会改变水生生态系统的营养生态，但关于侵入性物种如何改变湖相食物网中甲基汞（MeHg）生物放大率的研究还很有限。我们对加拿大魁北克的8个湖泊的地表水和生物区系进行了采样，测得的溶解有机碳（DOC）浓度范围为（2.9–8.4 mg / L）。当地的溪鳟（Salvelinus fontinalis）栖息着4个湖泊，其余的湖泊中则有溪鳟和一条非本地鱼类阿勒格尼珍珠pearl（Margariscus margarita）。附生，浮游动物，脊椎动物和鱼进行了分析：1）稳定碳（δ ¹³ C）和氮（δ ¹⁵N）描绘食物网的同位素比率，以及2）总Hg（THg）或MeHg。与来自参考湖泊河鳟鱼相比，从侵入湖泊鱼具有较高的长度标准化总汞浓度以及更窄的范围内的饮食和高架营养水平，从未经调整的δ推断¹³ C和δ ^15个分别N个值。汞在入侵湖和参考湖中的生物放大率相似，这表明入侵鱼类对甲基汞的营养转移影响很小。尽管珍珠珍珠入侵导致食物网结构不同，但是DOC是所有湖泊中鳟鳟THg含量的最强预测指标，表明与非本地饲料鱼相比，潜在环境因素对鳟鳟THg浓度的影响更大。 。2020年《环境毒理学》； 39：2196–2207。©2020 SETAC