Purdue University, Department of Forestry and Natural Resources, 195 Marsteller St., West Lafayette, IN 47907, USA; Ocean First Institute, 51 Shoreland Drive, Key Largo, FL 33037, USA.
Purdue University, Department of Biological Sciences, 915 W. State Street, West Lafayette, IN 47907, USA.
Sci Total Environ. 2023 Dec 15;904:166691. doi: 10.1016/j.scitotenv.2023.166691. Epub 2023 Sep 1.
Concentrations of microplastics in aquatic environments continue to rise due to industrial production and pollution. While there are various concerns regarding potential deleterious effects of microplastics on ecosystems, several knowledge gaps remain, including the potential for microplastics to directly and indirectly affect biotic interactions and food web dynamics. We explored the effects of environmentally relevant microplastic concentrations on two co-exposed species of herbaceous freshwater crustaceous zooplankton, filter feeding Daphnia dentifera and selective phytoplankton grazers Arctodiaptomus dorsalis. Study organisms were exposed to different concentrations of microplastics (plastic polyethylene microspheres; low = 2.38 × 10 mg/L, medium = 0.023 mg/L, high = 162 mg/L), phytoplankton prey, and predator cues, simulating a simple freshwater food web. Microplastic uptake was greater by D. dentifera, but both species were characterized by decreased algal consumption in the highest microplastic concentration treatment. Importantly, aqueous chlorophyll-a concentrations at the conclusion of the experiment were greater for the high microplastic treatment than all controls and other microplastic treatments. Finally, a predator effect was only apparent for D. dentifera, with greater microplastic uptake in the presence of a predator. We conclude that microplastics may adversely impact the ability of zooplankton to feed on algae and potentially release algae from consumptive control by herbivorous zooplankton. SYNOPSIS: This research aimed to better understand the broader food web effects of environmentally relevant microplastic concentrations on aquatic communities.
由于工业生产和污染，水生环境中的微塑料浓度持续上升。虽然人们对微塑料对生态系统可能产生的有害影响存在各种担忧，但仍存在一些知识空白，包括微塑料可能直接和间接影响生物相互作用和食物网动态的潜力。我们研究了环境相关浓度的微塑料对两种共暴露的淡水草食性甲壳类浮游动物（滤食性的 Daphnia dentifera 和选择性的浮游植物捕食者 Arctodiaptomus dorsalis）的影响。研究生物暴露于不同浓度的微塑料（塑料聚乙烯微球；低浓度 = 2.38×10mg/L，中浓度 = 0.023mg/L，高浓度 = 162mg/L）、浮游植物猎物和捕食者线索中，模拟一个简单的淡水食物网。D. dentifera 对微塑料的摄取量更大，但在最高微塑料浓度处理中，两种物种的藻类摄入量都减少了。重要的是，实验结束时高浓度微塑料处理的水中叶绿素-a 浓度高于所有对照和其他微塑料处理。最后，只有 D. dentifera 表现出捕食者效应，在存在捕食者的情况下，微塑料的摄取量更大。我们得出结论，微塑料可能会对浮游动物摄取藻类的能力产生不利影响，并可能使藻类免受草食性浮游动物的消耗控制。摘要：本研究旨在更好地了解环境相关微塑料浓度对水生群落的更广泛的食物网影响。
