Impact of Corbicula fluminae (Asian clam) on particulate matter transport in an urban stream.

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

Abstract: Wastewater treatment plant (WWTP) effluent is a significant source of anthropogenic N loading to urban streams and has been shown to impact the ability of streams to provide ecosystem services of nutrient retention and denitrification. If a stream is unable to provide these services, then the downstream systems will receive higher N loads potentially causing eutrophication and reduction of biodiversity. Corbicula fluminae (Asian clam) is an invasive species that has been shown to filter feed at a very high rate. I hypothesized that Corbicula functions to remove anthropogenic N at a sufficient rate to impact suspended particulate matter (seston) dynamics in a stream receiving treated urban wastewater. Stable isotope analysis was used as a tool to evaluate trophic relationships between seston and Corbicula. Fieldwork was conducted on North Buffalo Creek , NC, USA. Two laboratory experiments were performed to evaluate Corbicula filtering rate both in the presence and absence of stream sediment. Ash free dry mass (AFDM), ä15N, ä13C, C/N ratio, and chlorophyll a were measured over the course of 12 h in order to determine Corbicula impact on these seston variables over time. Field and experimental results showed that Corbicula in North Buffalo Creek was not filtering as has been described previously. My results indicate that Corbicula pedal feeds in the sediment. Therefore, instead of providing an ecosystem service of removing sewage-derived N from the water column, Corbicula returns sediment bound nutrients to the water column, thereby contributing further to downstream eutrophication.

Additional Information

Publication
Thesis
Language: English
Date: 2010
Keywords
Filter feeding, Nitrogen, Stable isotope, Urban streams
Subjects
Corbicula fluminea.
Stream ecology.
Urban ecology (Biology)