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

As a result of exposure to low water turbulence, periphyton are enriched in C-13 compared to phytoplankton. Because of this, benthic consumers in marine coastal environments are also C-13 enriched relative to planktonic consumers. I analyzed the delta(13)C values for biota from four Canadian Shield lakes and similarly found C-13 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.