Giusto Lo Bue1, Stanislas F. Dubois2, Claudie Quere3, Charlotte Corporeau3, Killian Guyomard2, Valerian Le Roy3, Nicoletta Mancin1
1University of Pavia, Italy - 2 Ifremer, France - 3IFREMER, Univ Brest, CNRS, IRD, LEMAR, France
Coastal sediments have been identified as hotspots for microplastic (MPs) accumulation worldwide: unfortunately their effects on benthic organisms inhabiting such ecosystems are still largely unknown. The gregarious polychaete Sabellaria alveolata (Linnaeus, 1767) colonizes intertidal zones by cementing sand particles into protective tubes forming biogenic reefs. While recent studies have documented MPs accumulation in arenaceous sabellariid reefs the potential effects of these pollutants remain unexplored. To partly fill this knowledge gap, the effects of MPs exposure on wild living S. alveolata specimens were investigated through a mesocosm experiment. The experimental design included 20 bioconstruction blocks ( 1 liter in volume each), collected from one of the largest European reef, i.e. the Champeaux reef (Normandie, France). Bioconstructions were equally distributed between control and exposure tanks containing polyethylene terephthalate (PET) micro-fragments (0.063-2 mm) during 28 days. Behavioral and eco-physiological responses were measured, respectively through daily photographs to assess feeding activity and through enzyme activity (in whole body) to quantify global antioxidant response and energy metabolism. Results showed an increased feeding activity in specimens from the exposure tank, unlike the control group which maintained consistent feeding patterns. The increase in feeding activity of exposed polychaete organisms in MP-contaminated water, likely reflects a behavioral adaptation to impaired feeding efficiency. It may also be an automatic mechanical response induced by the increase in the particulate load of the water triggered by the MPs. Biochemical analyses revealed treatment-dependent patterns in antioxidant response, suggesting potential effects of MPs exposure on superoxide dismutase activity, while energy metabolism showed sex-specific variations consistent across both control and exposed organisms.
Biography
Giusto Lo Bue is a PhD student at the Department of Earth and Environmental Sciences of Pavia University (Italy). He studies the effects of microplastic pollution on biogenic reefs built by sabellariid polychaetes. His work combines controlled laboratory experiments with field quantification and identification of pollutants in reef structures, assessing both accumulation patterns and biological impacts.