COLPLAI: Characterization of dissolved organic matter leached from plastics into seawater and its impact on marine mIcrobes

Presentation of Research Projects initiated in 2020 at ICM - 3rd sessionUp to 12.7 million metric tons (MT) of plastic entered the ocean only in 2010, threating marine fauna from small copepods to big mammals including human beings. Commercial plastic is never pure and it contains additives and plasticizers to improve the properties required for its purpose and to make it more resistant to degradation. When in contact with water, these additives can leach out to the aquatic medium. Plastic leaching is enhanced by solar radiation which can “photo-dissolve” plastic into dissolved organic carbon (DOC). Up to 23,600 metric tons of DOC is released per year from marine plastic. DOC makes part of different organic compounds constituting the dissolved organic matter (DOM) pool. The DOM leached from plastic is consumed by marine bacteria stimulating their growth. However, which type of bacteria are able to consume plastic leachates is still unknown. This project aims to understand the impact of plastic leachates on the carbon cycle and on marine microbes. It will study the chemical characteristics of the DOM leached from plastics into the seawater and the environmental conditions under which marine plastic leaching is higher. It will also analyze the impact of the organic compounds released by plastic into marine microbes and which are the bacterial groups and taxa consuming those leachatesPeer reviewe