Behaviour, a potential bioindicator for toxicity analysis of waterborne microplastics: A review

Recently, waterborne microplastics (MP) has raised significant public concerns. Therefore, a sensitive and macroscopic indicator is needed for the management and risk prediction of MP. Although MP-induced behavioural anomalies in aquatic species have been widely publicized, less attention has been given to the potential use of behavioural tests as bioindicators for MP ecotoxicity evaluations. This review summarizes the MP-induced behavioural anomalies and the possible affecting mechanisms, indicating that behaviours can provide sensitive and multifaceted revelations for biotoxicity evaluation. In addition, as technical advancements in computer vision, acoustic technology, and sensors have renovated conventional monitoring methods, their potential applications in behavioural monitoring of aquatic organisms in response to MP have been discussed, with the innovation trends of miniaturized devices, precise analysis, and multifunctional outputs highlighted. Challenges and prospects regarding behavioural investigations in future MP toxicity studies are also summarized. In conclusion, behaviour can be a potential bioindicator for MP toxicity analysis.