Programa de Pós-Graduação em Zoologia, Universidade Federal do Pará, Instituto de Ciências Biológicas, Rua Augusto Corrêa, 1, Guamá, Belém, PA, CEP: 66075-110, Brazil; Laboratório de Ecologia e Conservação, Instituto de Ciências Biológicas, Universidade Federal do Pará, Rua Augusto Corrêa, 1, Guamá, Belém, PA, CEP: 66075-110, Brazil.
Coordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia, Manaus, AM, CEP: 69067-375, Brazil.
Environ Pollut. 2023 Mar 15;321:121184. doi: 10.1016/j.envpol.2023.121184. Epub 2023 Jan 31.
Pollution and climate change are among the main threats to the biodiversity of freshwater ecosystems in the 21st century. We experimentally tested the effects of microplastic and climate change (i.e., increase in temperature and CO) on the survival and consumption by an Amazonian-stream shredder invertebrate. We tested three hypotheses. (1) Increased microplastic concentrations and climate change reduce shredder survival. We assumed that the combined stressors would increase toxic stress. (2) Increased concentrations of microplastics have negative effects on shredder food consumption. We assumed that blockage of the digestive tract by microplastics would lead to reduced ability to digest food. In addition, increased temperature and CO would lead to an increase in metabolic cost and reduced consumption. (3) The interaction between microplastics and climate change have greater negative effects on survival and consumption than either alone. We combined different concentrations of microplastic and climate change scenarios to simulate in real-time increases in temperature and CO forecast for 2100 for Amazonia. We found that both stressors had lethal effects, increasing mortality risk, but there was no interaction effect. Shredder consumption was negatively affected only by climate change. The interaction of microplastics and climate change on shredder consumption was dose-dependent and more intense in the extreme climate scenario, leading to reduced consumption. Our results indicate that microplastic and climate change may have strong effects on the consumption and/or survival of insect shredders in Amazonian streams. In addition, microplastic and climate change effects may affect not only populations but also ecosystem functioning (e.g., nutrient cycling). Integrative approaches to better understand and mitigate the effects of both stressors are necessary because plastic pollution and climate change co-occur in environments.
污染和气候变化是 21 世纪淡水生态系统生物多样性面临的主要威胁之一。我们通过实验测试了微塑料和气候变化（即温度和 CO2 增加）对亚马逊溪流撕食者无脊椎动物生存和摄食的影响。我们检验了三个假设。（1）增加的微塑料浓度和气候变化降低了撕食者的存活率。我们假设联合胁迫会增加毒性压力。（2）微塑料浓度增加对撕食者的食物摄食有负面影响。我们假设微塑料堵塞消化道会导致消化食物的能力降低。此外，温度和 CO2 增加会导致代谢成本增加和摄食量减少。（3）微塑料和气候变化的相互作用对生存和摄食的负面影响大于单一因素。我们结合了不同浓度的微塑料和气候变化情景，以模拟亚马逊地区 2100 年预测的实时增温增 CO2 情景。结果表明，这两个胁迫因素都有致死作用，增加了死亡率风险，但没有相互作用。仅气候变化对撕食者的摄食有负面影响。微塑料和气候变化对撕食者摄食的相互作用呈剂量依赖性，在极端气候情景下更为强烈，导致摄食减少。我们的研究结果表明，微塑料和气候变化可能对亚马逊溪流中昆虫撕食者的摄食和/或生存产生强烈影响。此外，微塑料和气候变化的影响可能不仅影响种群，还影响生态系统功能（例如，养分循环）。需要采取综合方法来更好地理解和减轻这两种胁迫因素的影响，因为它们在环境中共存。
