Abstract:
This study assesses for the first time the ingestion of microplastics by giant clams and evaluates their importance as a sink for this pollutant. A total of 24 individuals of two size classes were collected from the Red Sea and then exposed for 12 days to 4 concentrations of polyethylene microbeads ranging from 53 to 500 mm. Experiments revealed that clams actively take up microplastic from the water column and the average of beads retained inside the animal was ~7.55±1.89 beads individual 1 day 1 (5.76 ± 1.16 MPs/g dw). However, the digestive tract itself cannot be considered the only sink of microbeads in Tridacnids. Indeed, shells play a key role as well. The abundance of microplastic adhering to the shells, which was estimated directly, was positively correlated to the concentration of beads found in the surrounding seawater. Therefore, clams’ shells contribute to the removal of 66.03 ± 2.50% of the microplastic present in the water column. Furthermore, stress responses to the exposure to polyethylene were investigated. Gross Primary Production:Respiration (GPP:R) ratio decreased throughout the experiment, but no significant difference was found between treatments and controls.
Bio:
I did my bachelor in Biological Sciences in Torino (Italy), then I moved to Ancona (Italy) to obtain my master in Marine Biology, where I worked on several aspects of sea anemones’ biology, including their life cycle, symbiosis with zooxanthellae and Reactive Oxygen Species production (ROS). Then I was given a scholarship which allowed me to work at the University of Plymouth (UK), in their Aquatic Ecotoxicology laboratory. During this period, I investigated the effects of environmental contaminants, such as polycyclic aromatic hydrocarbons, on fish, embracing the 3Rs using only fish cells extracted from their guts. After this experience abroad, I moved back to Italy, where I worked in Science Communication and Education, mainly focusing on the marine environment. Then in 2018 I arrived at KAUST as a visiting student and the study that I am presenting today comes from this period as intern, conducted under the lead of Professor Carlos M. Duarte. I am currently a Ph.D. student in his laboratory, working on the “conditions of existence”: the role of co2 and o2 in modulating performance from marine organisms to human cells.