Bigheaded carps (BHCs; Silver Carp Hypophthalmichthys molitrix and Bighead Carp H. nobilis) are economically and culturally important in Asia and Europe but are considered highly invasive throughout the Mississippi River watershed and pose a threat to the food web and fisheries of the Laurentian Great Lakes. We used the Ecopath with Ecosim model framework to evaluate potential risk of BHC population growth and food web effects in four Great Lakes habitats, including mesotrophic waters of Saginaw Bay (Lake Huron) and Lake Erie and the oligotrophic main basins of Lakes Michigan and Huron. We simulated BHC population growth and food web effects under different scenarios of BHC production rates, prey vulnerability to BHCs, and availability of age-0 BHCs to predation by salmonines. In the main basins of Lakes Michigan and Huron, the projected BHC population growth was low or negative, with a projected final BHC biomass of 0.5–1.1 times the initial introductory biomass (2% of total fish biomass for each BHC species), and BHCs had negligible effects on most food web groups across all scenarios. In contrast, in Saginaw Bay and Lake Erie, the projected BHC biomass was 2.5–12.5 times higher than the initial biomass across all scenarios, and the largest increases occurred under scenarios of high prey vulnerability to BHCs and high BHC production rates. High projected BHC biomass in Saginaw Bay and Lake Erie had negative effects on zooplankton and planktivorous fish groups and mixed effects on piscivores but had relatively negligible effects on most other food web groups across all scenarios. Our results are consistent with reported BHC effects on food webs in the Mississippi River and its tributaries and inform efforts to prevent BHC invasion of the Great Lakes.

中文翻译：

---

鳙鱼对劳伦斯五大湖食物网的潜在影响

鳙鱼 (BHCs; Silver Carp Hypophthalmichthys molitrix和 Bighead Carp H. nobilis）在亚洲和欧洲具有重要的经济和文化意义，但在整个密西西比河流域被认为具有高度入侵性，并对劳伦斯大湖的食物网和渔业构成威胁。我们使用 Ecopath 和 Ecosim 模型框架来评估四个五大湖栖息地中 BHC 人口增长和食物网效应的潜在风险，包括萨吉诺湾（休伦湖）和伊利湖的中营养水域以及密歇根湖和休伦湖的贫营养主盆地。我们模拟了在 BHC 生产率、猎物对 BHC 的脆弱性以及 0 岁 BHC 被鲑鱼捕食的不同情况下的 BHC 种群增长和食物网效应。在密歇根湖和休伦湖的主要流域，预计 BHC 人口增长较低或为负，预计最终 BHC 生物量为 0.5-1。是初始引入生物量的 1 倍（每种 BHC 物种总鱼类生物量的 2%），并且 BHC 对所有情景中的大多数食物网组的影响都可以忽略不计。相比之下，在萨吉诺湾和伊利湖，在所有情景中，预计的 BHC 生物量比初始生物量高 2.5-12.5 倍，并且在猎物对 BHC 的高度脆弱性和高 BHC 生产率的情景下增幅最大。萨吉诺湾和伊利湖中高预测的 BHC 生物量对浮游动物和浮游鱼类群有负面影响，对食鱼动物有混合影响，但在所有情景中对大多数其他食物网群的影响相对可以忽略不计。我们的结果与报告的 BHC 对密西西比河及其支流食物网的影响一致，并为防止 BHC 入侵五大湖的努力提供信息。