Potential effects of the invasive bivalve, Corbicula fluminea, on methane cycle processes in an urban stream

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Robert S. Brown (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Anne Hershey

Abstract: Methanogenesis, subsequent methane oxidation and flux from sediments are subject to local biogeochemical conditions in streams. The invasive bivalve, Corbicula fluminea, has been shown to affect stream biogeochemistry and may have a density dependent effect on methane cycle processes via bioturbation and respiration. The response of methanogenesis rate, potential methane oxidation rate and net methane flux to Corbicula density was tested using laboratory microcosms. Potential methane oxidation decreased and net methane flux increased with increasing Corbicula density. This suggests that as Corbicula populations become denser, they have potential to increase methane flux from stream sediments by reducing methane oxidation. To test the response of sediment pore water methane concentration to Corbicula density, cage enclosures containing assigned Corbicula densities were installed in 3 blocks along a 50m stream reach. Corbicula had a marginally significant positive effect on pore water methane concentration in the downstream reach, but no significant effect in middle or upstream reaches. Sediment organic matter was highest downstream, providing potential substrate for methanogenesis. Active channel width was highest in the middle block, due to the presence of a sandbar. Increased organic matter availability and changes in hyporheic flow beneath the sandbar may have impacted Corbicula’s relationship with in situ methane concentrations. Considering the heterogeneity of urban streams, these relationships are likely site specific and probably vary within North Buffalo Creek.

Additional Information

Language: English
Date: 2018
Biogeochemistry, Consumers, Corbicula, Ecosystems, Methane, Streams
Corbicula fluminea
Biotic communities
Freshwater ecology

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