Briefly..
Mercury (Hg) is recognised as priority pollutant, impacting marine communities. Although phyto- and zooplankton are key components in marine systems little is known about Hg effects on natural communities. The volcanic-Hg impacted Deception Island provides perfect conditions to understand Hg effects on phyto- and zooplankton, and their physiological response and resistance mechanisms to cope with Hg contamination and its impacts on Hg biogeochemical cycling. In the project, Hg availability and phyto- and zooplankton community structure will be determined, and physiological processes (Hg accumulation, pigment profiles, photosynthesis, respiration, fatty acid (FA) composition, oxidative stress biomarkers, and Hg resistance proteins and peptides) assessed. The proposed research will provide lacking fundamental knowledge on the phyto- and zooplankton impacts on Hg biogeochemical cycling in austral ecosystems with potential application to other Hg contaminated environments worldwide.
The Hg-Planktarctic project aims to:
Determine and update Hg and MeHg levels in dissolved and particulate (phyto- and zooplankton) compartments in Deception Island Hg-impacted areas and open ocean.
Evaluate Hg effects on phyto- and zooplankton biomass, composition and morphological features.
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Quantify physiological (photosynthesis and respiration) and biochemical features namely, pigments, FA, non-enzymatic (TBARS, ROOH, RC=O) and enzymatic (activities of SOD, CAT, GPx and GST) oxidative stress biomarkers of phyto- and zooplankton, to identify which and how these processes affect Hg cycling.
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Sequence and quantify abundance of natural phyto- and zooplankton OTUs and the correspondent transcriptomic profile, GO terms and KEGG annotations, with emphasis on Hg resistome, to provide insight on both communities ability to tolerate and resist Hg.
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Provide a phyto- and zooplankton resistance index to assess the health status of Hg contaminated marine system worldwide, with relevance to global marine management guidelines.
