Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, UK.
National Marine Science Centre, Southern Cross University, Coffs Harbour, 2450, Australia.
Environ Pollut. 2020 Apr;259:113855. doi: 10.1016/j.envpol.2019.113855. Epub 2019 Dec 23.
The potential influence of microplastic debris on marine organisms is an issue of great ecological and socioeconomic concern. Experiments exposing fishes and invertebrates to constant concentrations of microplastics often yield high variation in particle ingestion rates among individuals. Yet, despite an increasing interest in microplastic ingestion in the wild, the potential intrinsic drivers of inter-individual variation have received little attention so far. Here we assessed individual-level ingestion of Polyethylene microspheres by laboratory-reared juvenile anemonefish, Amphiprion ocellaris, in relation to (a) ambient particle concentrations and (b) repeatable behavioural traits. We show that microplastic ingestion is highly variable at all tested particle concentrations and that this variation can partially be explained by individual activity levels. Moreover, the relationship between ingestion and behavioural variation increased notably when only the most behaviourally consistent individuals (n = 40 out of 60) were considered in the analysis. Our findings indicate that microplastic ingestion rates in juvenile reef fishes may be less dependent on ambient concentrations than expected; instead they are to some degree phenotype-dependent. Care should thus be taken when reporting mean responses to microplastic exposure treatments, because some individuals may not be affected in the same way as others due to differential ingestion behaviour. We also discuss potential ramifications of non-random ingestion variability on population- and community-level responses.
微塑料碎片对海洋生物的潜在影响是一个具有重大生态和社会经济意义的问题。将鱼类和无脊椎动物暴露于恒定浓度的微塑料中的实验往往会导致个体之间的颗粒摄入量存在很大差异。然而，尽管人们对野外摄入微塑料的兴趣日益增加，但迄今为止，个体间变异的潜在内在驱动因素还没有得到太多关注。在这里，我们评估了实验室饲养的幼年海葵鱼（Amphiprion ocellaris）个体对聚乙稀微球的摄入情况，与（a）环境颗粒浓度和（b）可重复的行为特征有关。我们发现，在所有测试的颗粒浓度下，微塑料的摄入都存在高度的可变性，这种变异性可以部分解释为个体的活动水平。此外，当仅考虑分析中最具行为一致性的个体（n=60 个中的 40 个）时，摄入与行为变化之间的关系显著增加。我们的研究结果表明，幼年珊瑚鱼的微塑料摄入率可能不像预期的那样依赖于环境浓度；相反，它们在一定程度上取决于表型。因此，在报告对微塑料暴露处理的平均反应时应谨慎，因为由于摄入行为的差异，某些个体可能不会像其他个体那样受到影响。我们还讨论了非随机摄入变异性对种群和群落水平反应的潜在影响。
