Anthropogenic stressors that affect ecological processes in the Laurentian Great Lakes can impact their susceptibility to bioinvasions. Bighead Hypophthalmichthys nobilis and Silver Carp H. molitrix, collectively ‘bigheaded carps’ (BHC), are planktivorous fishes threatening to invade Lake Michigan. While previous studies indicate the lake contains habitat suitable for BHC growth, there is a need to understand how anthropogenic-driven changes to the abiotic and biotic environment could alter its vulnerability to BHC. We applied a spatially explicit model of BHC growth rate potential (GRP; g g⁻¹ d⁻¹) to nine biophysical model scenarios to evaluate changes in habitat suitability in Lake Michigan. Scenarios differed in meteorology (cool, reference, warm), annual tributary phosphorus loads (0, 3300, and 5600 MTA), and the presence/absence of invasive dreissenid mussels. Mussel effects on BHC GRP relied on their contact with the surface mixed layer (SML), the depth of which was affected by meteorology. The warm year advanced the expansion of Bighead Carp habitat by increasing temperature-dependent foraging rates and lessening the time of competitive interaction with mussels due to earlier stratification separating mussels from the SML. Phosphorus loads were the most influential driver of the lake’s suitability. Compared to present conditions, we estimate BHC could have grown an additional 8–40% annually in the 1980s when mussels were not in the lake and phosphorus loads were higher. Our study demonstrates how climate change and nutrient enrichment can increase Lake Michigan’s vulnerability to BHC by affecting thermal regime and productivity, thereby limiting negative effects of dreissenid mussels on BHC growth.

影响劳伦式五大湖生态过程的人为压力源可能会影响其对生物入侵的敏感性。鳙鳙，鲢H.鲢，统称“bigheaded鲤鱼”（BHC），是planktivorous鱼类威胁入侵密歇根湖。尽管先前的研究表明该湖包含适合BHC生长的栖息地，但有必要了解人为驱动的非生物和生物环境变化如何改变其对BHC的脆弱性。我们应用了BHC增长率潜力的空间显式模型（GRP; gg ^-1 d ^-1）的九个生物物理模型方案，以评估密歇根湖栖息地适应性的变化。在气象（冷，参考，暖），年度支流磷负荷（0、3300和5600 MTA）以及是否存在侵入性地塞米氏贻贝方面，情况有所不同。贻贝对BHC GRP的影响取决于它们与表面混合层（SML）的接触，其深度受气象学的影响。温暖的一年通过增加与温度相关的觅食率并减少了与贻贝的竞争性相互作用而缩短了head鱼栖息地的扩张，这是由于较早的分层将贻贝从SML中分离出来的缘故。磷负荷是影响该湖适宜性的最主要因素。与目前的状况相比 我们估计，在贻贝不在湖中且磷含量较高的情况下，1980年代BHC可能以每年8-40％的速度增长。我们的研究表明，气候变化和养分富集如何通过影响热量状况和生产力，从而增加密歇根湖对BHC的脆弱性，从而限制了杜鹃贻贝对BHC生长的负面影响。