Impacts of microplastics combined with octocrylene on key organisms of the trophic web: Artemia salina and Pocillopora damicornis
Supervisors: Didier Stien, Philippe Lebaron U Sorbonne (Banyuls)
Plastic discovery brought evolution to modern society with many utilities in many fields such as industry or medicine. Its production exponentially rose for the past decades, being multiplied by almost 200 between 1950 and 2015. Divided in different polymers from 1 to 7, plastics fit several needs. This amount of plastic produced overwhelms countries recycling capacities leading to a global waste of it, ending for a part of it, in the oceans. Mainly land-based, plastic waste is distributed worldwide in every stage of the ocean, from the surface to the sediments. Through abiotic and biotic processes, plastic pieces degrade down to microplastic fragments from a micron up to 5 millimetres. Microplastic occurrence in oceans can trigger side effects to aquatic organisms down to pioneer species and first link species of trophic web such as corals and copepods. From entanglement to oxidative stress, impacts of microplastics as a pollutant itself and coupled to adsorbed organic pollutants are wide. In order to assess microplastic impacts as a pollutant and as a pollutant vector on two key species, Pocillopora damicornis and Artemia salina, they were exposed to different concentrations of microplastic fragments for ten days. As microplastic exposure didn’t trigger significant mortality for A. salina, it could be interesting to look at the sublethal parameters such as reproduction and mobility when exposing. After HPLC-MS analyses, P. damicornis exposure highlighted potential effects such as stress biomarkers synthesis that could be more marked by a longer exposure time or a higher concentration of microplastics.