Plan Estatal de Investigación Científica y Técnica y de Innovación (CNS2022-135524) (2023-2025)
MOMa: Microbial and Organic Matter as drivers of mercury biogeochemical cycling in Marine particles.
Marine particles – including settling and suspended particles – provide microhabitats with anaerobic niches for microorganisms and it has been speculated that they are suitable habitats for Hg methylators because this process happens in absence of oxygen. Determining MeHg formation in sinking particles and the microorganisms involved in the process is of major importance to quantify the MeHg flux that goes from sinking particles to low trophic level biota (e.g., zooplankton), and thus the threat of this pelagic source of MeHg to biomagnification rates. Among the drivers controlling Hg methylation, the composition of organic matter is one of the most relevant. It has been shown that on one hand labile, phytoplankton-derived organic matter boost the activity of microbial communities, including Hg-methylators, and on the other hand it provides low molecular mass thiols that increase Hg availability. The overall aim of MOMA is to provide mechanistic understanding on the drivers, particularly the molecular composition of organic matter, Hg and MeHg levels in the ocean at a global scale.
The specific objectives of MOMa are:
a) Evaluate the diversity of Hg-cycling microorganisms on the global ocean
b) Investigate the environmental conditions controlling the diversity and composition of Hg-cycling microbial groups.
c) Determine the bio-physico-chemical conditions regulating the activity of Hg-cycling microorganisms.
The specific objectives of MOMa are:
a) Evaluate the diversity of Hg-cycling microorganisms on the global ocean
b) Investigate the environmental conditions controlling the diversity and composition of Hg-cycling microbial groups.
c) Determine the bio-physico-chemical conditions regulating the activity of Hg-cycling microorganisms.
Proyectos de I+D+I Retos de investigación (JIN, PID2019-111722RJ-100) (2020-2023)
MerTerMar: Role of submarine groundwater discharge on Mercury cycling: unveiling the link between Terrestrial and Marine systems in a changing world (MerTerMar)
Although coastal groundwater aquifers are increasingly recognized as major sources of materials, carbon and nutrients to the world’s oceans, their contribution in terms of Hg are completely unknown. MerTerMar seeks to determine the role of coastal groundwater aquifers on the transfer of Hg and MeHg from land to sea. In particular, MerTerMar studied the the transport of Hg from terrestrial systems to the marine environment via this overlooked subsurface pathway. MerTerMar also explored whether MeHg might be formed in coastal groundwater aquifers or if the discharge of nutrients from land to sea enhance the formation of MeHg in the Mediterranean coasts. Of all the environmental interfaces, this terrestrial-marine groundwater link is likely one of the least studied. In particular, due to the semi-enclosed and oligotrophic nature of the Mediterranean Sea, the influence of such groundwater-mediated continental inputs will be much larger than in larger oceans. This makes the Mediterranean Sea an ideal system to study the ecological and biogeochemical consequences of this overlooked hydrological pathway. We are working on the publications derived from this project. PhD Thesis of Maria Montero Curiel (SO, FPI CEX2019-000928-S) is linked to this project. The objectives of MerTerMar are:
a) To quantify the concentrations of HgII and MeHg in coastal aquifers and calculate their export to the Mediterranean Sea.
b) To determine the effect of groundwater discharge on the formation of MeHg in the coastal areas
c) To identify the organisms involved in Hg cycling at the terrestrial-groundwater-marine continuun
a) To quantify the concentrations of HgII and MeHg in coastal aquifers and calculate their export to the Mediterranean Sea.
b) To determine the effect of groundwater discharge on the formation of MeHg in the coastal areas
c) To identify the organisms involved in Hg cycling at the terrestrial-groundwater-marine continuun
Individual Fellowship, MARIE SKŁODOWSKA-CURIE ACTIONS (H2020-MSCA-IF-2016) (2018-2020)
MER-CURE: Using global marine metagenomics to understand MERcury microbial associated processes: finding a CURE for mercury contaminated environments
Anthropogenic perturbations have alarmingly tripled the mercury content of surface Earth reservoirs (atmosphere, ocean, or terrestrial) compared to pre-anthropogenic conditions. Nowadays, millions of people are exposed to harmful levels of this potent neurotoxin, concretely to the organic form methylmercury that bio-accumulates in organisms and biomagnifies in marine food webs. Understanding mercury transformations within the oceanic water column remains a critical issue because fish harvested for commercial use originates largely from marine ecosystems, and are a primary source of methylmercury to humans globally. In order to increase the knowledge on mercury cycling in the ocean, MER-CURE is structured around four objectives:
a) To identify key microbial prokaryotic populations involved in Hg processes in the marine environments at a global ocean scale
b) To provide quantitative data of the amount of methylmercury and inorganic mercury that can be degraded/eliminated in the sea
c) To quantify mercury detoxification rates in bacterial cultures and marine contaminated sediments to develop a pilot-system for Hg removal
d) To engage stakeholders in the management process, to develop and implement a communication strategy based on formative purposes to effectively translate and share research achievements from objectives "a" to "c"
Relevant publications:
E. Capo, B. D Peterson, M. Kim, D.S Jones, S. G Acinas, M. Amyot, S. Bertilsson, E. Björn, M.Buck, C. Cosio, D. A Elias, C. Gilmour, M. S. Goñi Urriza, B. Gu, H. Lin, Y.‐R. Liu, K. McMahon, J. W Moreau, J. Pinhassi, M. Podar, F. Puente‐Sánchez, P. Sanchez, V. Storck, Y. Tada, A. Vigneron, D. Walsh, M. Vandewalle‐Capo, A. G. Bravo*, C. Gionfriddo*. 2023. A consensus protocol for the recovery of mercury methylation genes from metagenomes. Molecular Ecology Resources 23(1), 190-204.
E. Capo, E. Broman, S. Bonaglia, A.G. Bravo, S. Bertilsson, A.L. Soerensen,et al., 2022. Oxygen‐deficient water zones in the Baltic Sea promote uncharacterized Hg methylating microorganisms in underlying sediments. Limnology and Oceanography 67 (1), 135-146.
I. Sanz-Sáez, C. Pereira-García, A.G. Bravo, L. Trujillo, M. Pla i Ferriol, et al., 2022. Prevalence of heterotrophic methylmercury detoxifying bacteria across oceanic regions. Environmental Science & Technology 56 (6), 3452-3461.
E. Capo, C. Feng, A.G. Bravo, S. Bertilsson, A.L Soerensen, J. Pinhassi, M. Buck, C. Karlsson, J. Hawkes, E. Björn. Expression levels of hgcAB genes and mercury availability jointly explain methylmercury formation in stratified brackish waters.2022. Environmental Science & Technology 56 (18), 13119-13130.