Vol.:(0123456789) 1 3 Bulletin of Environmental Contamination and Toxicology https://doi.org/10.1007/s00128-019-02587-0 No Efect of Polystyrene Microplastics on Foraging Activity and Survival in a Post-larvae Coral-Reef Fish, Acanthurus triostegus Hugo Jacob 1,2  · Arthur Gilson 1  · Chantal Lanctôt 2,3  · Marc Besson 1,2  · Marc Metian 2  · David Lecchini 1,4 Received: 13 November 2018 / Accepted: 4 March 2019 © Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract Microplastics (MP) are ubiquitous in the marine environment and have been shown to alter the behaviour of some species due to potential neurotoxic efect. However, very little is known on the efect of this stressor on behavioural responses of early and more vulnerable life stages. This study explores the efects of polystyrene MP (90 µm diameter) on the foraging activity of newly settled surgeonfsh Acanthurus triostegus and on their survival facing predators. Exposure to a high concentra- tion of 5 MP particles per mL (5 MP mL −1 ) for 3, 5 and 8 days did not alter their foraging activity nor their susceptibility to predation. This suggests that short-term exposures to reportedly high MP concentrations have negligible efects on the behaviour of newly settled A. triostegus. Nevertheless, responses to MP can be highly variable, and further research is needed to determine potential ecological efects of MP on reef fsh populations during early-life stages. Keywords Plastic pollution · Behaviour · Feeding · Predation · Larval recruitment · Acanthurus triostegus There is increasing evidence that exposure to microplastics (MP) leads to adverse efects on marine animals (Wright et al. 2013). In fsh, MP have been found to cause physi- cal and physiological defects, such as false food satiation, tissue damage and decreased swimming performance (Lu et al. 2016; Pedà et al. 2016; Barboza et al. 2018a; Critch- ell and Hoogenboom 2018). However, despite the range of sub-lethal efects reported, the efects of MP on fsh behav- iour remain poorly understood. For example, while MPs have been reported to cause lethargic and erratic swimming behaviours in the European seabass, Dicentrarchus labrax (Barboza et al. 2018b), other studies found no signifcant efects on fsh behaviour (e.g. Guven et al. 2018; Tosetto et al. 2017). Discrepancies could be due to several factors including diferences in MP concentrations, plastic types, species and life stages. Consequently, more research is needed to elucidate the efects of MP on the behaviour of aquatic species, such as foraging and predator avoidance. Indeed, these behaviours are not only fundamental to indi- viduals’ ftness and functional role in their ecosystem (Wolf and Weissing 2012), but also their modifcations are consid- ered among the most sensitive indicators of environmental disturbances (Hellou 2011; Melvin and Wilson 2013). In addition to the lack of understanding regarding behav- ioural responses in fsh exposed to MP, limited information is also available on their efects on early-life stages of marine organisms that may be particularly sensitive to environmen- tal disturbances (van Dam et al. 2011; Mazurais et al. 2015; Besson et al. 2017; Holzer et al. 2017). The vast majority of coral-reef associated fshes have a stage-structured life his- tory, with a relatively sedentary benthic juvenile and adult stage preceded by a pelagic larval stage (Leis and Mccor- mick 2002). The transition between larval and juvenile stages occurs when pelagic larvae enter and settle in the reef environment. This step is referred to as the larval recruit- ment phase and involves a range of physical and behavioral changes (i.e. metamorphosis) that are controlled by thyroid hormones (Holzer et al. 2017). This metamorphic phase is often referred to as a ‘critical period’ in coral-reef fsh life * Marc Metian m.metian@iaea.org 1 PSL Research University: EPHE-UPVD-CNRS, USR, 3278 CRIOBE, BP 1013, 98729 Papetoai, Moorea, French Polynesia 2 International Atomic Energy Agency - Environment Laboratories, 4a Quai Antoine Ier, 98000 Principality of Monaco, Monaco 3 Australian Rivers Institute, Grifth University, Southport, QLD 4215, Australia 4 Laboratoire d’Excellence “CORAIL”, 98729 Papetoai, Moorea, French Polynesia