@article{fdi:010074892,
  title = {{A}lgal bloom exacerbates hydrogen sulfide and methylmercury contamination in the emblematic high-altitude lake {T}iticaca},
  author = {{A}cha, {D}. and {G}u{\'e}dron, {S}t{\'e}phane and {A}mouroux, {D}. and {P}oint, {D}avid and {L}azzaro, {X}avier and {F}ernandez, {P}. {E}. and {S}arret, {G}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A}lgal blooms occurrence is increasing around the globe. {H}owever, algal blooms are uncommon in dominantly oligotrophic high-altitude lakes. {L}ake {T}iticaca, the largest freshwater lake in {S}outh {A}merica, located at 3809 m above the sea level, experienced its first recorded algal bloom covering a large fraction of its southern shallow basin in {M}arch-{A}pril 2015. {T}he dominant algae involved in the bloom was {C}arteria sp. {W}ater geochemistry changed during the bloom with a simultaneous alkalinization in heterotrophic parts of the lake and acidification in eutrophic shallow areas. {A} decrease in oxygen saturation (from 105 to 51%), and a dramatic increase in hydrogen sulfide ({H}2{S}) concentrations (from <0.02 to up to 155 mu g.{L}-1) resulted in the massive death of pelagic organisms. {S}uch changes were brought by the exacerbated activity of sulfate-reducing bacteria ({SRB}) in this sulfate-rich lake. {A}lthough levels in total mercury remained stable during the event, {MMH}g% rose, highlighting higher conservation of produced {MMH}g in the water. {S}uch an increase on {MMH}g% has the potential to produce exponential changes on {MMH}g concentrations at the end food web due to the biomagnification process. {O}ur physicochemical and climatological data suggest that unusually intense rain events released large amounts of nutrients from the watershed and triggered the bloom. {T}he observed bloom offers a hint for possible scenarios for the lake if pollution and climate change continue to follow the same trend. {S}uch a scenario may have significant impacts on the most valuable fish source in the {A}ndean region and the largest freshwater {L}ake in {S}outh {A}merica. {F}urthermore, the event illustrates a possible fate of high altitude environments subjected to eutrophication.},
  keywords = {eutrophication ; climate change ; sulfate reduction ; extreme rain ; mercury ; nutrient enrichment ; {PEROU} ; {BOLIVIE} ; {ANDES} ; {TITICACA} {LAC}},
  booktitle = {},
  journal = {{G}eosciences},
  volume = {8},
  numero = {12},
  pages = {art. 438 [18 p.]},
  ISSN = {2076-3263},
  year = {2018},
  DOI = {10.3390/geosciences8120438},
  URL = {https://www.documentation.ird.fr/hor/fdi:010074892},
}