BiDiRisk

PTDC/CTA-AMB/2894/2021
Biomarker discovery for risk assessment in the deep sea

Seafloor massive sulphides at deep-sea hydrothermal vents and natural gas hydrates in some methane seeps are of interest for resource extraction. However, the cost-benefit of deep-sea mining (DSM) need to accurately account for the scale of environmental impact, the ecosystem services that might be compromised and the potential mitigation measures that can be implemented. DSM may remove the habitat locally where the mining operations will take place and create localized sediment plumes caused by mining collectors at the seafloor, potentially introducing complex mixtures of potentially toxic elements in the water column. The climate change impact is the major concern related to the exploitation of deep-sea methane hydrates while the potential effects of sediment removal and resuspension have been much neglected so far. In situ experiments with local fauna are scarce but considered essential to better assess the potential impact of DSM . During this project, experiments will be performed at vents of the Mid-Atlantic Ridge (MAR) and at seeps in the northwest Pacific. This project aims to develop sound methodologies and discover new biomarkers from deep-sea species that can be used to assess and monitor environmental risk in deep-sea chemosynthetic ecosystems. It will contribute to answer the question: What are the potential environmental impacts of deep-sea resource exploitation of vents and seeps? The innovative aspects of this project are: 1) first in situ experiments at methane seeps addressing the potential ecotoxicological effects of sediments resuspension; 2) first study dedicated to the identification of specific biomarkers responding to sediments/sulphides and Cu exposure in deep-sea chemosynthetic species; 3) provide new insights into the evolution and adaptation to environmental change of congeneric species from different chemosynthetic environments.

Project Main Goals:

"This project aims to develop sound methodologies and discover new biomarkers from deep-sea species that can be used to assess and monitor environmental risk in deep-sea chemosynthetic ecosystems. To achieve the aim, the following objectives will be addressed:
1- Assess the baseline environmental status at hydrothermal vents and methane seeps, using ecotoxicological bioassays to evaluate the ecotoxicity of sulphides and local sediments, and analysing a battery of biomarkers in key and dominant local species;
2- Quantify the ecotoxicological effects of in situ exposure to sulphides or sediments and copper-spiked sulphides or sediments in the mussels Bathymodiolus azoricus and B. platifrons, respectively;
3- Assess the baseline and quantify the effects of in situ exposure in the amino acid stable isotope signature in the two Bathymodiolus species and associated fauna using amino acid isotopic analysis;
4- Identify protein biomarker candidates after in situ exposure in the two Bathymodiolus species using iTRAQ/TMT-based comparative proteomics followed by biomarkers verification using sandwich ELISA (enzyme-linked immunosorbent assay) methods;
5- Classify the environmental hazard after in situ exposures in comparison to controls using a Weight Of Evidence (WOE) model."

OTHER TEAM MEMBERS // PARTNERS

This project involves researchers from CIMA/UALG, IMAR, Ifremer, the Hong-Kong University of Science and Technology, and the Ocean University of China.