Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Experimental d13C evidence for a contribution of methane to pelagic food webs in lakes
AU - Kankaala, Paula
AU - Taipale, Sami
AU - Grey, Jonathan
AU - Sonninen, Eloni
AU - Arvola, L.
AU - Jones, Roger
PY - 2006/11
Y1 - 2006/11
N2 - We tested the hypothesis that low stable carbon isotope (δ13C) values commonly observed for zooplankton in humic lakes are due to their feeding on isotopically light methane-oxidizing microbes, and thus that methane-derived carbon is important in the food webs of these lakes. In replicate laboratory cultures, Daphnia longispina, a common crustacean zooplankter in humic lakes, were fed microbial suspensions with or without enrichment by biogenic methane. The δ13C values of Daphnia indicated consumption of 13C-depleted methanotrophic bacteria, while growth rates, survival, and reproduction of Daphnia in cultures enriched with methane were equal to or greater than those in nonenriched cultures. Results from lake enclosures during the autumn overturn period revealed a decrease in δ13C of adult Daphnia from -40.5% to -50.3%, reflecting extensive consumption of 13C-depleted methanotrophic bacteria. Methane-derived carbon is a more important contribution to carbon flux through lake pelagic food webs than has previously been suspected.
AB - We tested the hypothesis that low stable carbon isotope (δ13C) values commonly observed for zooplankton in humic lakes are due to their feeding on isotopically light methane-oxidizing microbes, and thus that methane-derived carbon is important in the food webs of these lakes. In replicate laboratory cultures, Daphnia longispina, a common crustacean zooplankter in humic lakes, were fed microbial suspensions with or without enrichment by biogenic methane. The δ13C values of Daphnia indicated consumption of 13C-depleted methanotrophic bacteria, while growth rates, survival, and reproduction of Daphnia in cultures enriched with methane were equal to or greater than those in nonenriched cultures. Results from lake enclosures during the autumn overturn period revealed a decrease in δ13C of adult Daphnia from -40.5% to -50.3%, reflecting extensive consumption of 13C-depleted methanotrophic bacteria. Methane-derived carbon is a more important contribution to carbon flux through lake pelagic food webs than has previously been suspected.
U2 - 10.4319/lo.2006.51.6.2821
DO - 10.4319/lo.2006.51.6.2821
M3 - Journal article
VL - 51
SP - 2821
EP - 2827
JO - Limnology and Oceanography
JF - Limnology and Oceanography
SN - 0024-3590
IS - 6
ER -