By Isabel García Arévalo & Sonja Gindorf

During the first semester of 2022, Isabel (ESR6) worked on 8 experiments of Hg species uptake and sorption by living particles in collaboration with a Master student and later on with Sonja (ESR 7) who joined for her secondment. These time-course experiments were focused on studying iHg and MMHg species sorption and uptake, as a factor of time and dissolved organic matter exposure, by a model species of marine microalgae. The axenic cultures of Tisochrysis lutea (T-iso) along with the experimental set-up were carried out in the facilities of PhyTox laboratory, while all the Hg pertinent analysis were carried out in the laboratory of CCEM, both at Ifremer Nantes.

In April, ESR 7 Sonja joined the laboratory work for a four-week secondment. During the first week of her stay the ESRs ran a MMHg uptake experiment together and studied the time-course ad- and absorption of MMHg by microalgae cells. For the rest of Sonja’s stay they focused on how dissolved organic matter (DOM) composition (terrestrial vs. marine) and concentration affect the MMHg uptake of T-iso using isotopically labelled MMHg tracers. The samples are now awaiting to be shipped to Stockholm University. In fall, Isabel will spend her secondment at Stockholm University and the two girls will perform the analysis together.