W. F. Fitzgerald and C. H. Lamborg, Geochemistry of Mercury in the Environment, Treatise on Geochemistry, pp.91-129, 2014.

S. Guédron, S. Audry, D. Acha, S. Bouchet, D. Point et al., Diagenetic production, accumulation and sediment-water exchanges of methylmercury in contrasted sediment facies of Lake Titicaca (Bolivia), Science of The Total Environment, vol.723, p.138088, 2020.

S. Guédron, L. Huguet, D. A. Vignati, B. Liu, F. Gimbert et al., Tidal cycling of mercury and methylmercury between sediments and water column in the Venice Lagoon (Italy), Marine Chemistry, vol.130-131, pp.1-11, 2012.

S. Bouchet, D. Amouroux, P. Rodriguez-gonzalez, E. Tessier, M. Monperrus et al., MMHg production and export from intertidal sediments to the water column of a tidal lagoon (Arcachon Bay, France), Biogeochemistry, vol.114, issue.1-3, pp.341-358, 2013.
URL : https://hal.archives-ouvertes.fr/hal-00794115

J. M. Benoit, D. H. Shull, R. M. Harvey, and S. A. Beal, Effect of Bioirrigation on Sediment?Water Exchange of Methylmercury in Boston Harbor, Massachusetts, Environmental Science & Technology, vol.43, issue.10, pp.3669-3674, 2009.

C. R. Hammerschmidt and W. F. Fitzgerald, Sediment?water exchange of methylmercury determined from shipboard benthic flux chambers, Marine Chemistry, vol.109, issue.1-2, pp.86-97, 2008.

S. Hamelin, M. Amyot, T. Barkay, Y. Wang, and D. Planas, Methanogens: Principal Methylators of Mercury in Lake Periphyton, Environmental Science & Technology, vol.45, issue.18, pp.7693-7700, 2011.

D. Achá, V. Iniguez, M. Roulet, J. R. Guimarães, R. Luna et al., Sulfate-Reducing Bacteria in Floating Macrophyte Rhizospheres from an Amazonian Floodplain Lake in Bolivia and Their Association with Hg Methylation, Appl. Environ. Microbiol, vol.71, pp.7531-7535, 2005.

A. G. Bravo, S. Bouchet, S. Guédron, D. Amouroux, J. Dominik et al., High methylmercury production under ferruginous conditions in sediments impacted by sewage treatment plant discharges, Water Research, vol.80, pp.245-255, 2015.

E. J. Kerin, C. C. Gilmour, E. Roden, M. T. Suzuki, J. D. Coates et al., Mercury Methylation by Dissimilatory Iron-Reducing Bacteria, Applied and Environmental Microbiology, vol.72, issue.12, pp.7919-7921, 2006.

D. Point, M. Monperrus, E. Tessier, D. Amouroux, L. Chauvaud et al., Biological control of trace metal and organometal benthic fluxes in a eutrophic lagoon (Thau Lagoon, Mediterranean Sea, France), Estuarine, Coastal and Shelf Science, vol.72, issue.3, pp.457-471, 2007.
URL : https://hal.archives-ouvertes.fr/hal-00460083

S. Guedron, D. Cossa, M. Grimaldi, and L. Charlet, Methylmercury in tailings ponds of Amazonian gold mines (French Guiana): Field observations and an experimental flocculation method for in situ remediation, Applied Geochemistry, vol.26, issue.2, pp.222-229, 2011.
URL : https://hal.archives-ouvertes.fr/insu-00565075

K. Y. Choe, G. A. Gill, R. D. Lehman, S. Han, W. A. Heim et al., Sediment-water exchange of total mercury and monomethyl mercury in the San Francisco Bay-Delta, Limnology and Oceanography, vol.49, issue.5, pp.1512-1527, 2004.

U. Skyllberg, Competition among thiols and inorganic sulfides and polysulfides for Hg and MeHg in wetland soils and sediments under suboxic conditions: Illumination of controversies and implications for MeHg net production, Journal of Geophysical Research: Biogeosciences, vol.113, issue.G2, pp.n/a-n/a, 2008.

S. Bouchet, M. Goñi-urriza, M. Monperrus, R. Guyoneaud, P. Fernandez et al., Linking Microbial Activities and Low-Molecular-Weight Thiols to Hg Methylation in Biofilms and Periphyton from High-Altitude Tropical Lakes in the Bolivian Altiplano, Environmental Science & Technology, vol.52, issue.17, pp.9758-9767, 2018.
URL : https://hal.archives-ouvertes.fr/hal-01980778

, npj Science of Learning, Appl. Sci, vol.2020, p.7936

S. Guédron, S. Devin, and D. A. Vignati, Total and methylmercury partitioning between colloids and true solution: From case studies in sediment overlying and porewaters to a generalized model, Environmental Toxicology and Chemistry, vol.35, issue.2, pp.330-339, 2016.

E. W. Helbling, V. Villafañe, A. Buma, M. Andrade, and F. Zaratti, DNA damage and photosynthetic inhibition induced by solar ultraviolet radiation in tropical phytoplankton (Lake Titicaca, Bolivia), European Journal of Phycology, vol.36, issue.2, pp.157-166, 2001.

L. Alanoca, D. Amouroux, M. Monperrus, E. Tessier, M. Goni et al., Diurnal variability and biogeochemical reactivity of mercury species in an extreme high-altitude lake ecosystem of the Bolivian Altiplano, Environmental Science and Pollution Research, vol.23, issue.7, pp.6919-6933, 2015.
URL : https://hal.archives-ouvertes.fr/hal-01439880

L. Alanoca, S. Guédron, D. Amouroux, S. Audry, M. Monperrus et al., Synergistic effects of mining and urban effluents on the level and distribution of methylmercury in a shallow aquatic ecosystem of the Bolivian Altiplano, Environmental Science: Processes & Impacts, vol.18, issue.12, pp.1550-1560, 2016.
URL : https://hal.archives-ouvertes.fr/hal-02075682

J. Tapia, S. Audry, and P. Van-beek, Natural and anthropogenic controls on particulate metal(loid) deposition in Bolivian highland sediments, Lake Uru Uru (Bolivia), The Holocene, vol.30, issue.3, pp.428-440, 2019.

G. Sarret, S. Guédron, D. Acha, S. Bureau, F. Arnaud-godet et al., Extreme Arsenic Bioaccumulation Factor Variability in Lake Titicaca, Bolivia, Scientific Reports, vol.9, issue.1, 2019.
URL : https://hal.archives-ouvertes.fr/hal-02339758

J. Tapia and S. Audry, Control of early diagenesis processes on trace metal (Cu, Zn, Cd, Pb and U) and metalloid (As, Sb) behaviors in mining- and smelting-impacted lacustrine environments of the Bolivian Altiplano, Applied Geochemistry, vol.31, pp.60-78, 2013.

S. Guedron, M. Grimaldi, C. Grimaldi, D. Cossa, D. Tisserand et al., Amazonian former gold mined soils as a source of methylmercury: Evidence from a small scale watershed in French Guiana, Water Research, vol.45, issue.8, pp.2659-2669, 2011.
URL : https://hal.archives-ouvertes.fr/insu-00680384

S. Guédron, D. Point, D. Acha, S. Bouchet, P. A. Baya et al., Mercury contamination level and speciation inventory in Lakes Titicaca & Uru-Uru (Bolivia): Current status and future trends, Environmental Pollution, vol.231, pp.262-270, 2017.

N. S. Bloom and W. F. Fitzgerald, Determination of volatile mercury species at the picogram level by low-temperature gas chromatography with cold-vapour atomic fluorescence detection, Analytica Chimica Acta, vol.208, pp.151-161, 1988.

D. Cossa, B. Averty, and N. Pirrone, The origin of methylmercury in open Mediterranean waters, Limnology and Oceanography, vol.54, issue.3, pp.837-844, 2009.

S. Guédron, C. Duwig, B. L. Prado, D. Point, M. G. Flores et al., (Methyl)Mercury, Arsenic, and Lead Contamination of the World?s Largest Wastewater Irrigation System: the Mezquital Valley (Hidalgo State?Mexico), Water, Air, & Soil Pollution, vol.225, issue.8, pp.1-19, 2014.

D. Achá, S. Guédron, D. Amouroux, D. Point, X. Lazzaro et al., Algal Bloom Exacerbates Hydrogen Sulfide and Methylmercury Contamination in the Emblematic High-Altitude Lake Titicaca, Geosciences, vol.8, issue.12, p.438, 2018.

M. Monperrus, P. Rodriguez-gonzalez, D. Amouroux, J. I. Garcia-alonso, and O. F. Donard, Evaluating the potential and limitations of double-spiking species-specific isotope dilution analysis for the accurate quantification of mercury species in different environmental matrices, Analytical and Bioanalytical Chemistry, vol.390, issue.2, pp.655-666, 2007.
URL : https://hal.archives-ouvertes.fr/hal-01590318

A. Sharif, M. Monperrus, E. Tessier, S. Bouchet, H. Pinaly et al., Fate of mercury species in the coastal plume of the Adour River estuary (Bay of Biscay, SW France), Science of The Total Environment, vol.496, pp.701-713, 2014.
URL : https://hal.archives-ouvertes.fr/hal-01982193

A. Sharif, M. Monperrus, E. Tessier, S. Bouchet, H. Pinaly et al., Fate of mercury species in the coastal plume of the Adour River estuary (Bay of Biscay, SW France), Science of The Total Environment, vol.496, pp.701-713, 2014.
URL : https://hal.archives-ouvertes.fr/hal-01982193

J. M. Small and H. Hintelmann, Methylene blue derivatization then LC?MS analysis for measurement of trace levels of sulfide in aquatic samples, Analytical and Bioanalytical Chemistry, vol.387, issue.8, pp.2881-2886, 2007.

J. M. Small and H. Hintelmann, Sulfide and mercury species profiles in two Ontario boreal shield lakes, Chemosphere, vol.111, pp.96-102, 2014.

R. A. Berner and . Early-diagenesis, , p.240, 1980.

B. P. Boudreau, The diffusive tortuosity of fine-grained unlithified sediments, Geochimica et Cosmochimica Acta, vol.60, issue.16, pp.3139-3142, 1996.

S. E. Rothenberg, R. F. Ambrose, and J. A. Jay, Mercury cycling in surface water, pore water and sediments of Mugu Lagoon, CA, USA, Environmental Pollution, vol.154, issue.1, pp.32-45, 2008.

C. Dill, T. Kuiken, H. Zhang, and M. Ensor, Diurnal variation of dissolved gaseous mercury (DGM) levels in a southern reservoir lake (Tennessee, USA) in relation to solar radiation, Science of The Total Environment, vol.357, issue.1-3, pp.176-193, 2006.

M. Amyot, G. Mierle, D. Lean, and D. J. Mc-queen, Effect of solar radiation on the formation of dissolved gaseous mercury in temperate lakes, Geochimica et Cosmochimica Acta, vol.61, issue.5, pp.975-987, 1997.

A. L. Soerensen, A. T. Schartup, E. Gustafsson, B. G. Gustafsson, E. Undeman et al., Eutrophication Increases Phytoplankton Methylmercury Concentrations in a Coastal Sea?A Baltic Sea Case Study, Environmental Science & Technology, vol.50, issue.21, pp.11787-11796, 2016.

P. Lei, L. M. Nunes, Y. Liu, H. Zhong, and K. Pan, Mechanisms of algal biomass input enhanced microbial Hg methylation in lake sediments, Environment International, vol.126, pp.279-288, 2019.

K. H. Knorr, DOC-dynamics in a small headwater catchment as driven by redox fluctuations and hydrological flow paths ? are DOC exports mediated by iron reduction/oxidation cycles?, Biogeosciences, vol.10, issue.2, pp.891-904, 2013.

S. P. Feyte, C. Gobeil, A. Tessier, and D. Cossa, Mercury dynamics in lake sediments, Geochimica et Cosmochimica Acta, vol.82, pp.92-112, 2012.

J. Hellal, S. Guédron, L. Huguet, J. Schäfer, V. Laperche et al., Mercury mobilization and speciation linked to bacterial iron oxide and sulfate reduction: A column study to mimic reactive transfer in an anoxic aquifer, Journal of Contaminant Hydrology, vol.180, pp.56-68, 2015.
URL : https://hal.archives-ouvertes.fr/hal-01399012

J. M. Benoit, C. C. Gilmour, and R. P. Mason, Aspects of Bioavailability of Mercury for Methylation in Pure Cultures of Desulfobulbus propionicus (1pr3), Applied and Environmental Microbiology, vol.67, issue.1, pp.51-58, 2001.

G. A. Gill, N. S. Bloom, S. Cappellino, C. T. Driscoll, C. Dobbs et al., Sediment?Water Fluxes of Mercury in Lavaca Bay, Texas, Environmental Science & Technology, vol.33, issue.5, pp.663-669, 1999.

P. C. Pickhardt and N. S. Fisher, Accumulation of Inorganic and Methylmercury by Freshwater Phytoplankton in Two Contrasting Water Bodies, Environmental Science & Technology, vol.41, issue.1, pp.125-131, 2007.

R. Quiroga-flores, S. Guédron, and D. Achá, High methylmercury uptake by green algae in Lake Titicaca: Potential implications for remediation, Ecotoxicology and Environmental Safety, vol.207, p.111256, 2021.

D. Point, G. Bareille, H. Pinaly, C. Belin, and O. F. Donard, Multielemental speciation of trace elements in estuarine waters with automated on-site UV photolysis and resin chelation coupled to inductively coupled plasma mass spectrometry, Talanta, vol.72, issue.3, pp.1207-1216, 2007.
URL : https://hal.archives-ouvertes.fr/hal-01557341

D. Achá, C. A. Pabón, and H. Hintelmann, Mercury methylation and hydrogen sulfide production among unexpected strains isolated from periphyton of two macrophytes of the Amazon, FEMS Microbiology Ecology, vol.80, issue.3, pp.637-645, 2012.

E. Gascón-díez, J. Loizeau, C. Cosio, S. Bouchet, T. Adatte et al., Role of Settling Particles on Mercury Methylation in the Oxic Water Column of Freshwater Systems, Environmental Science & Technology, vol.50, issue.21, pp.11672-11679, 2016.

S. Audry, G. Blanc, J. Schäfer, G. N. Chaillou, and S. B. Robert, Early diagenesis of trace metals (Cd, Cu, Co, Ni, U, Mo, and V) in the freshwater reaches of a macrotidal estuary, Geochimica et Cosmochimica Acta, vol.70, issue.9, pp.2264-2282, 2006.
URL : https://hal.archives-ouvertes.fr/hal-00324600

R. B. Wanty and M. B. Goldhaber, Thermodynamics and kinetics of reactions involving vanadium in natural systems: Accumulation of vanadium in sedimentary rocks, Geochimica et Cosmochimica Acta, vol.56, issue.4, pp.1471-1483, 1992.

A. M. Graham, K. T. Cameron-burr, H. A. Hajic, C. Lee, D. Msekela et al., Sulfurization of Dissolved Organic Matter Increases Hg?Sulfide?Dissolved Organic Matter Bioavailability to a Hg-Methylating Bacterium, Environmental Science & Technology, vol.51, issue.16, pp.9080-9088, 2017.

E. Von-wachenfeldt and L. J. Tranvik, Sedimentation in Boreal Lakes?The Role of Flocculation of Allochthonous Dissolved Organic Matter in the Water Column, Ecosystems, vol.11, issue.5, pp.803-814, 2008.

J. Yan, V. Lazouskaya, and Y. Jin, Soil Colloid Release Affected by Dissolved Organic Matter and Redox Conditions, Vadose Zone Journal, vol.15, issue.3, p.vzj2015.02.0026, 2016.

W. G. Lanza, D. Achá, D. Point, J. Masbou, L. Alanoca et al., Association of a Specific Algal Group with Methylmercury Accumulation in Periphyton of a Tropical High-Altitude Andean Lake, Archives of Environmental Contamination and Toxicology, vol.72, issue.1, pp.1-10, 2016.
URL : https://hal.archives-ouvertes.fr/hal-01499137

H. A. Moye, C. J. Miles, E. J. Phlips, B. Sargent, and K. K. Merritt, Kinetics and Uptake Mechanisms for Monomethylmercury between Freshwater Algae and Water, Environmental Science & Technology, vol.36, issue.16, pp.3550-3555, 2002.

L. Deng, D. Fu, and N. Deng, Photo-induced transformations of mercury(II) species in the presence of algae, Chlorella vulgaris, Journal of Hazardous Materials, vol.164, issue.2-3, pp.798-805, 2009.

M. Andrade, R. Forno, E. Palenque, and F. Zaratti, Estudio preliminar del efecto de altura sobre la radiación solar ultravioleta B, Rev. Bol. Fis, 1998.

M. Blumthaler, W. Ambach, and W. Rehwald, Solar UV-A and UV-B radiation fluxes at two alpine stations at different altitudes, Theor. Appl. Climatol, vol.46, pp.39-44, 1992.

V. E. Villafae, M. Andrade, V. Lairana, F. Zaratti, and E. W. Helbling, Inhibition of phytoplankton photosynthesis by solar ultraviolet radiation: studies in Lake Titicaca, Bolivia, Freshwater Biology, vol.42, issue.2, pp.215-224, 1999.

S. J. Klapstein and N. J. O?driscoll, Methylmercury Biogeochemistry in Freshwater Ecosystems: A Review Focusing on DOM and Photodemethylation, Bulletin of Environmental Contamination and Toxicology, vol.100, issue.1, pp.14-25, 2017.

R. S. Oremland, C. W. Culbertson, and M. R. Winfrey, Methylmercury Decomposition in Sediments and Bacterial Cultures: Involvement of Methanogens and Sulfate Reducers in Oxidative Demethylation, Applied and Environmental Microbiology, vol.57, issue.1, pp.130-137, 1991.

S. J. Klapstein, S. E. Ziegler, and N. J. O'driscoll, Methylmercury photodemethylation is inhibited in lakes with high dissolved organic matter, Environmental Pollution, vol.232, pp.392-401, 2018.

S. J. Klapstein, S. E. Ziegler, D. A. Risk, and N. J. O'driscoll, Quantifying the effects of photoreactive dissolved organic matter on methylmercury photodemethylation rates in freshwaters, Environmental Toxicology and Chemistry, vol.36, issue.6, pp.1493-1502, 2016.

J. D. Jeremiason, J. C. Portner, G. R. Aiken, A. J. Hiranaka, M. T. Dvorak et al., Photoreduction of Hg(ii) and photodemethylation of methylmercury: the key role of thiol sites on dissolved organic matter, Environmental Science: Processes & Impacts, vol.17, issue.11, pp.1892-1903, 2015.

B. Ni, J. R. Kramer, R. A. Bell, and N. H. Werstiuk, Protonolysis of the Hg?C Bond of Chloromethylmercury and Dimethylmercury. A DFT and QTAIM Study, The Journal of Physical Chemistry A, vol.110, issue.30, pp.9451-9458, 2006.

D. Zhang, Y. Yin, Y. Li, Y. Cai, and J. Liu, Critical role of natural organic matter in photodegradation of methylmercury in water: Molecular weight and interactive effects with other environmental factors, Science of The Total Environment, vol.578, pp.535-541, 2017.

B. Senamhi, Servicio Nacional de Meteorología de Hidrología. La PazBoliv, 2020.