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MERCURY INHIBITION ON PRIMARY PRODUCTIVITY USING LARGE VOLUME PLASTIC CHAMBERS IN SITU 1
Author(s) -
Blinn Dean W.,
Tompkins Terrill,
Zaleski Larry
Publication year - 1977
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/j.1529-8817.1977.tb02887.x
Subject(s) - phytoplankton , mercury (programming language) , diatom , water column , incubation , environmental chemistry , algae , biology , photosynthesis , in situ , zoology , nutrient , ecology , botany , chemistry , biochemistry , computer science , programming language , organic chemistry
Approximately 6000 l of lake water was suspended in large, clear plastic chambers in Lake Powell, Arizona. The chambers were monitored during 24 h incubation periods in the spring and summer 1974 and 1975. Physico‐chemical differences between the natural lake system and within the experimental chambers were negligible. Experimental mercury concentrations ranging from < 0.02 to 1.25 ppm were added to the chambers to determine the effect of elevated Hg concentrations on in situ primary production. Mercury concentrations were monitored in the water column of each chamber during each 24 h incubation period to determine absolute concentrations following reduction through adsorption, absorption and vaporization. At least a 40% reduction in photosynthetic activity occurred at Hg concentrations as low as 0.06 ppm. A toxic Hg threshold concentration of 0.06 ppm was demonstrated for the summer phytoplankton assemblage, but a distinct threshold concentration was absent for the spring diatom assemblage. Differences in spring and summer phytoplankton populations may suggest subtle differences in Hg sensitivity between phytoplankton assemblages in combination with temperature acting on total community metabolism.