Many coastal ecosystems, including those of the Laurentian Great Lakes, suffer from various natural and anthropogenic stressors. Given that multiple stressors often concomitantly impact ecosystems, it may be difficult to disentangle which stressors are most influential. Upper trophic level communities, such as fish assemblages, can provide insights to the influence of diverse stressors as they may integrate cumulative effects over the long-term and also reflect responses of lower trophic levels. We used multivariate analyses and assemblage indices to investigate long-term (1984–2016) patterns in a nearshore fish assemblage indexed via annual trawling in the Indiana waters of southern Lake Michigan. Based on observations from other regions of the Great Lakes, we expected that oligotrophication, due to reduced nutrient loading and filtering by invasive mussels, would have a strong influence on the fish assemblage. However, we were unsure if the very nearshore fish assemblage would track observed decreased production patterns in offshore Lake Michigan or if observed increased primary production in the very nearshore would affect the fish assemblage. Consistent with the former expectation, overall abundance and richness of the assemblage declined over time. However, contrary to observations in other regions there was no overall evidence of species tolerant to more eutrophic conditions being replaced by more sensitive species. Moreover, there was limited evidence of the fish assemblage shifting towards species more tolerant of warm water, as might be expected with climate change. While increased numbers of invasive species added species to the system, overall species richness and native species richness declined.

许多沿海生态系统，包括劳伦森五大湖的生态系统，都受到各种自然和人为压力的影响。鉴于多种压力源经常同时影响生态系统，可能很难弄清楚哪些压力源最具影响力。上营养级鱼类群落等群落可以提供对不同压力源影响的见解，因为它们可以整合长期的累积效应，也反映了较低营养水平的反应。我们使用多元分析和组合指数来研究通过每年在密歇根湖南部的印第安纳水域进行的拖网捕捞索引的近岸鱼类组合中的长期（1984-2016 年）模式。根据对五大湖其他地区的观察，我们预计由于营养负荷减少和入侵贻贝的过滤，贫营养化将对鱼类群落产生强烈影响。然而，我们不确定非常近岸的鱼类群是否会跟踪观察到的密歇根湖近海产量下降的模式，或者观察到的非常近岸的初级产量增加是否会影响鱼类群。与之前的预期一致，该组合的整体丰度和丰富度随着时间的推移而下降。然而，与其他地区的观察结果相反，没有总体证据表明耐受更多富营养化条件的物种被更敏感的物种所取代。此外，只有有限的证据表明鱼类群落转向更能耐受温水的物种，正如气候变化所预期的那样。虽然人数增加 与其他地区的观察结果相反，没有总体证据表明耐受更多富营养化条件的物种被更敏感的物种所取代。此外，只有有限的证据表明鱼类群落转向更能耐受温水的物种，正如气候变化所预期的那样。虽然人数增加 与其他地区的观察结果相反，没有总体证据表明耐受更多富营养化条件的物种被更敏感的物种所取代。此外，只有有限的证据表明鱼类群落转向更能耐受温水的物种，正如气候变化所预期的那样。虽然人数增加入侵物种增加了系统物种，整体物种丰富度和本地物种丰富度下降。