USDA Forest Service

Pacific Southwest Research Station

Pacific Southwest
Research Station

800 Buchanan Street
Albany, CA 94710-0011
(510) 883-8830
United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Development of a risk model to determine the expansion and potential environmental impacts of Asian clams in Lake Tahoe

Principal Investigators:
Sudeep Chandra, University of Nevada-Reno
Marion Wittmann, University of Notre Dame
Geoff Schladow, University of California-Davis
John Reuter, University of California-Davis

Proposal [pdf]

Final Report [pdf]

Please contact Dr. Sudeep Chandra with questions regarding the final report.

Project Summary

In the last 40 years many private and public resources have been expended to restore Lake Tahoe’s fragile ecosystem and water clarity. Recently, the expansion of an invasive species, the Asian clam, was documented in the southeastern part of the lake. The rapid expansion of Asian clam in one year, combined with the demonstrated potential to alter the ecology of the lake via unprecedented levels of algal biomass in the nearshore, represents a major new threat to Lake Tahoe.

This proposal was motivated by concerns of agency staff requests for assistance in developing control methods, predicting likely future locations for clam colonization, and assessing the impact of clams on both a local and entire-lake scale. The invasion of Asian clam in a high elevation, oligotrophic, coldwater lake is unique; most introduced species in Lake Tahoe show various life history adjustments and/or phenotypic plasticities compared to other populations in North America. The early detection of this common invader in Lake Tahoe allows for critical research at the beginning stages of an invasion in a rare environment.

The primary goal of this project was to develop a risk analysis of Asian clam distribution and its environmental impact by examining the structure, transport, life history, and energetics of existing populations discovered in the lake.