Microplastics reduce net population growth and fecal pellet sinking rates for the marine copepod, Acartia tonsa
Microplastics reduce net population growth and fecal pellet sinking rates for the marine copepod, Acartia tonsa
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微塑料降低了海洋桡足类 Acaria tonsa 的净种群增长和粪便颗粒下沉率
DOI：
10.1016/j.envpol.2021.117379
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发表时间：
2021
影响因子：
8.9
通讯作者：
Pespeni, Melissa H.
中科院分区：
文献类型：
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作者：
Shore, Emily A.;deMayo, James A.;Pespeni, Melissa H.
微塑料（<5 毫米）在全球环境中无处不在，并且越来越被认为是一种生物危害，特别是在海洋中。众所周知，位于海洋食物网底部的浮游动物会消耗微塑料。然而，我们对微塑料在生命史阶段和碳沉降方面的影响知之甚少。在这里，我们研究了桡足类 Acariatonsaon 摄入中性浮力聚苯乙烯珠 (6.68μm) 的影响 (1) 整个生命史阶段的生长和存活，(2) 繁殖力和卵子质量，(3) 和粪便特征。我们发现，暴露于微塑料会缩短无节幼体的体长和存活率，并且当桡足类在卵子发生过程中暴露于微塑料时，会导致产下较小的卵。结合这些生活史影响，我们的模型估计，在接触微塑料的情况下，人口增长将减少 15%，导致数量在 1 年或 20 代内减少 30 倍。此外，受微塑料污染的粪便颗粒变小了 2.29 倍，下沉速度据计算减慢了 1.76 倍，导致每天沉降到底栖动物的粪便量估计减少了 4.03 倍。总而言之，种群规模和粪便沉降率的下降表明，浮游动物消耗的微塑料可能会通过减少营养能量转移和减慢碳沉降而对生态系统产生级联影响。
Microplastics (<5 mm) are ubiquitous in the global environment and are increasingly recognized as a biological hazard, particularly in the oceans. Zooplankton, at the base of the marine food web, have been known to consume microplastics. However, we know little about the impacts of microplastics across life history stages and on carbon settling. Here, we investigated the effects of ingestion of neutrally buoyant polystyrene beads (6.68μm) by the copepodAcartia tonsaon (1) growth and survival across life history stages, (2) fecundity and egg quality, (3) and fecal characteristics. We found that microplastic exposure reduced body length and survival for nauplii and resulted in smaller eggs when copepods were exposed during oogenesis. Combining these life history impacts, our models estimate a 15% decrease in population growth leading to a projected 30-fold decrease in abundance over 1 year or 20 generations with microplastic exposure. In addition, microplastic-contaminated fecal pellets were 2.29-fold smaller and sinking rates were calculated to be 1.76-fold slower, resulting in an estimated 4.03-fold reduction in fecal volume settling to the benthos per day. Taken together, declines in population sizes and fecal sinking rates suggest that microplastic consumption by zooplankton could have cascading ecosystem impacts via reduced trophic energy transfer and slower carbon settling.