Impact of microplastics on locomotor behavior of aquatic organisms

Environmentally relevant concentrations of microplastics influence the locomotor activity of aquatic biota

 

 

Microplastics ecotoxicity tested on zebrafish larvae

• Microplastics (MPs) inhibited the locomotor activity by 6% at realistic concentrations
• MPs decreased the average speed by 5% and the moved distance by 8%
• Egger’s test indicated the results were stable without obvious publication bias
• Effects presented size-, time-, concentration-dependent patterns and multi-factors interactions
• Potential mechanisms underlying MPs-induced locomotor activity decline were provided

Abstract

The occurrence of microplastics (MPs) in various marine and freshwater matrices has attracted great attention. However, the effect of MPs in natural environment on the locomotor performance of aquatic biota is still controversial. Therefore, this meta-analysis was conducted, involving 116 effect sizes from 2347 samples, to quantitatively evaluate the alteration in locomotor behavior of aquatic organisms induced by MPs at environmentally relevant concentrations (≤ 1 mg/L, median = 0.125 mg/L). It was shown that MP exposure significantly inhibited the average speed and moved distance of aquatic organisms by 5% and 8% (p < 0.05), respectively, compared with the control, resulting in an obvious reduction of locomotor ability by 6% (p < 0.05). Egger’s test indicated that the results were stable without publication bias (p > 0.05). The complex influence of MPs on the locomotor ability were characterized through random-effects meta-regression analyses, presenting size-, time-, concentration-dependent manners and multi-factors interactions. In addition, several physiological changes, including energy reserve reduction, metabolism disorder, gut microbiota dysbiosis, inflammation response, neurotoxic response, and oxidative stress, of aquatic organisms triggered by MP exposure at environmentally relevant concentrations were also provided, which might account for the MPs-induced locomotor activity decline.

 

Link to the publication :

https://www.sciencedirect.com/science/article/abs/pii/S0304389421005446