Asian clam (Corbicula fluminea) shells, Truckee River at McCarran Ranch. March 10, 2015. Photo: K.McCutcheon.
These tiny filter-feeding clams were introduced to the United States from Southeast Asia, and first observed in the Columbia River in 1938. Since then, Asian clams have spread across the country and can now be found in many of the waterways of the western, southern and eastern US (Voshell 2002). Asian clams were discovered in Lake Tahoe in 2002, and have since been found in densities of up to 8,000 clams per square meter (Wittman et al. 2011). Asian clams have also been observed on the Lower Truckee River near Clark, NV (Lawrence & Seiler 2002) and in Donner Lake (MAP 2013). If you find Asian clams in other places, please record an observation!
The Asian Clam (Corbicula sp.) was the only type of clam found in the Truckee River during a 1993-1997 survey of aquatic invertebrates (Lawrence & Seiler 2002). In Lake Tahoe, the Asian clam is considered a threat to the health of the lake, because clams excrete nutrients and stimulate the growth of algae, causing water clarity to decline. Researchers from University of Nevada, Reno and UC Davis and other organizations are currently investigating ways to control or remove clams from Lake Tahoe using rubber barriers. For more information, visit the website of University of Nevada, Reno’s Aquatic Ecosystems Analysis Laboratory.
Lawrence, S. J. and Seiler, R.L. 2002. Aquatic Invertebrates, and Fish from Selected Reaches on the Carson and Truckee Rivers, Nevada and California, 1993 – 97. United States Geological Survey, Open-File Report 02-012.
Mountain Area Preservation. 2013. Donner Lake: Boat Inspections and Aquatic Invasive Species. Blog post: June 12, 2013. Available online at http://www.mapf.org/2013/06/12/
Wittmann, M.E., Gamble, A.E., Allen, B.C., Webb, K., Reuter, J.E., Chandra, S., and S.G. Schladow. 2011. The Control of Asian clam (Corbicula fluminea) in Lake Tahoe with Benthic Barriers: The Influence of Water Temperature on Mortality. Final report. Available online at http://terc.ucdavis.edu/publications/documents/marlabayfinalreport.pdf
Voshell, J. Reese., and Amy Bartlett. Wright. 2002. A Guide to Common Freshwater Invertebrates of North America. Blacksburg, VA: McDonald & Woodward Pub.
USGS. 2014. Asian Clam. Nonindigenous Aquatic Species Database. U.S. Geological Survey. Gainesville, Florida. Accessed 12/4/2014.