Stable isotope analysis of benthic fauna and their food sources in boreal lakes
2010 (English)In: Journal of The North American Benthological Society, ISSN 0887-3593, E-ISSN 1937-237X, Vol. 29, no 4, 1339-1348 p.Article in journal (Refereed) Published
The origin of organic C supporting zoobenthic communities in 8 boreal lakes with different concentrations of dissolved organic C (DOC) was assessed by stable-isotope analysis. Profundal zoobenthos was depleted in C-13 compared to littoral zoobenthos, and this difference increased with decreasing DOC concentration. The delta C-13 of littoral zoobenthos suggested reliance on benthic algae, whereas depleted C-13 of profundal zoobenthos could be explained by contributions from allochthonous and autochthonous C sources. In deeper lakes, profundal zoobenthos diets also included C processed by methanotrophic bacteria. Littoral zoobenthos delta C-13 decreased with increasing DOC concentration in the lake water. Our results suggest that littoral benthic fauna are mainly supported by benthic algae in low-DOC lakes and by phytoplankton and allochthonous organic C in high-DOC lakes and that this difference is a result of light absorbance and energy supply by allochthonous organic C. Increasing allochthonous DOC inputs, as expected in a warmer and wetter climate, might reduce benthic algal production and alter the organic C base for benthic food webs in lake ecosystems.
Place, publisher, year, edition, pages
2010. Vol. 29, no 4, 1339-1348 p.
autochthonous, allochthonous, dissolved organic C, stable isotopes, boreal lakes
IdentifiersURN: urn:nbn:se:uu:diva-135091DOI: 10.1899/10-002.1ISI: 000283891800012OAI: oai:DiVA.org:uu-135091DiVA: diva2:374745