Differentiation between littoral and pelagic food webs in lakes using stable carbon isotopes

Abstract

As a result of exposure to low water turbulence, periphyton are enriched in 13 C compared to phytoplankton. Because of this, benthic consumers in marine coastal environments are also 13 C enriched relative to planktonic consumers. I analyzed the δ 13 C values for biota from four Canadian Shield lakes and similarly found 13 C enrichment in littoral compared to pelagic consumers. A compilation of literature data indicates that an uncoupling of carbon flows between benthic and planktonic food webs may be a characteristic feature of lakes worldwide.