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Methylmercury enters an aquatic food web through acidophilic microbial mats in Yellowstone National Park, Wyoming
Author(s) -
Boyd Eric S.,
King Susan,
Tomberlin Jeffery K.,
Nordstrom D. Kirk,
Krabbenhoft David P.,
Barkay Tamar,
Geesey Gill G.
Publication year - 2009
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2008.01820.x
Subject(s) - food web , trophic level , biology , biomagnification , microbial loop , ecology , primary producers , microbial mat , methylmercury , biomass (ecology) , microbial food web , phototroph , aquatic ecosystem , environmental chemistry , botany , cyanobacteria , bioaccumulation , photosynthesis , phytoplankton , nutrient , bacteria , chemistry , genetics
Summary Microbial mats are a visible and abundant life form inhabiting the extreme environments in Yellowstone National Park (YNP), WY, USA. Little is known of their role in food webs that exist in the Park's geothermal habitats. Eukaryotic green algae associated with a phototrophic green/purple Zygogonium microbial mat community that inhabits low‐temperature regions of acidic (pH ∼ 3.0) thermal springs were found to serve as a food source for stratiomyid (Diptera: Stratiomyidae) larvae. Mercury in spring source water was taken up and concentrated by the mat biomass. Monomethylmercury compounds (MeHg + ), while undetectable or near the detection limit (0.025 ng l −1 ) in the source water of the springs, was present at concentrations of 4–7 ng g −1 dry weight of mat biomass. Detection of MeHg + in tracheal tissue of larvae grazing the mat suggests that MeHg + enters this geothermal food web through the phototrophic microbial mat community. The concentration of MeHg + was two to five times higher in larval tissue than mat biomass indicating MeHg + biomagnification occurred between primary producer and primary consumer trophic levels. The Zygogonium mat community and stratiomyid larvae may also play a role in the transfer of MeHg + to species in the food web whose range extends beyond a particular geothermal feature of YNP.