Microplastic leachates impair behavioural vigilance and predator avoidance in a temperate intertidal gastropod

Area of Science:

• Marine Biology
• Ecotoxicology
• Chemical Ecology

Background:

• Microplastics are widespread marine contaminants with known impacts on marine life.
• However, the effects of microplastic leachates on predator-prey interactions mediated by chemical cues remain largely unknown.
• Understanding these impacts is crucial for assessing the ecological risks of microplastic pollution.

Purpose of the Study:

• To investigate the effects of microplastic leachates on the chemical detection and antipredator behaviors of the intertidal gastropod Littorina littorea.
• To determine if microplastic leachates impair the ability of L. littorea to detect and respond to chemical cues from its predator, the crab Carcinus maenas.

Main Methods:

• Exposure of L. littorea to leachates derived from virgin and beached microplastic pellets.
• Behavioral assays measuring L. littorea's vigilance and antipredator responses to C. maenas chemical cues.
• Quantification of changes in L. littorea's behavioral responses due to leachate exposure.

Main Results:

• Microplastic leachates significantly altered the behavioral responses of L. littorea to predator chemical cues.
• Leachates from virgin pellets impaired L. littorea's vigilance and antipredator behaviors.
• Leachates from beached pellets inhibited these behaviors, increasing prey vulnerability.
• These findings demonstrate direct biological effects of microplastic leachates on marine invertebrate behavior.

Conclusions:

• Microplastic leachates pose a significant threat to marine ecosystems by disrupting predator-prey interactions.
• The impairment of chemosensory-mediated behaviors increases the vulnerability of marine organisms to predation.
• These results highlight the urgent need to consider the ecotoxicological impacts of microplastic leachates on marine food webs.