Invasive crayfish can cause shifts in lakes from clear, macrophyte-dominated states to eutrophic, phytoplankton-dominated states because of their burrowing and foraging behavior. While invasive crayfish populations have been linked to declines in water clarity of shallow lakes and wetlands in Asia and Europe, little research has been done on the potential for similar effects of invasive rusty crayfish (Faxonius rusticus) in large temperate lakes of the Midwestern USA. We related F. rusticus abundance in 17 lakes of northern Wisconsin, USA over time (1984‒2018) to measures of lake clarity (chlorophyll a concentration and Secchi disc depth) estimated from remote sensing (Landsat imagery). Contrary to the effects of invasive crayfish in other study systems, we found a weak, positive association between F. rusticus abundance and water clarity. We propose that lake clarity may increase if declines in small fishes caused by F. rusticus lead to population growth of zooplankton and consequent decreases in phytoplankton through a trophic cascade. Alternatively, F. rusticus could be passengers to, rather than drivers of, lake clarity trends, responding positively to increased littoral benthic productivity when lakes are clearer. Future research should aim to determine if F. rusticus causes or responds to changes in water clarity, but should also investigate the impacts of crayfish invasions on water clarity across a greater variety of lentic ecosystems.

由于它们的挖洞和觅食行为，入侵的小龙虾会导致湖泊从清澈的、以大型植物为主的状态转变为富营养化、以浮游植物为主的状态。虽然入侵的小龙虾种群与亚洲和欧洲浅湖和湿地的水透明度下降有关，但很少有研究表明入侵锈小龙虾（Faxonius rusticus）在美国中西部的大型温带湖泊中可能产生类似影响。我们与F.天牛丰威斯康星州北部，美国的17个湖泊随时间（1984年至2018年），以湖清晰度的措施（叶绿素一浓度和 Secchi 圆盘深度）从遥感（Landsat 图像）估计。与其他研究系统中侵入性小龙虾的影响相反，我们发现F. rusticus丰度与水透明度之间存在微弱的正相关。我们建议，如果F. rusticus引起的小鱼数量下降导致浮游动物种群增长，从而导致浮游植物通过营养级联减少，那么湖泊的透明度可能会增加。或者，F. rusticus可能是湖泊清澈度趋势的乘客，而不是驱动者，当湖泊更清澈时，对增加的沿海底栖生产力做出积极响应。未来的研究应该旨在确定F. rusticus 导致或响应水透明度的变化，但还应调查小龙虾入侵对更多种类的静水生态系统水透明度的影响。