Quagga Mussels in Lake Tahoe

Affiliation(s) PI Project period Funded by
DHS Acharya, Kumud 04/13/2012 - 12/31/2014 University of Nevada, Reno

Project Description

Quagga and zebra mussels are establishing in western waterways with large densities in the Colorado Aqueduct system and established populations in North Central Califomia. This invasion is already having profound ecological and economic impacts in these ecosystems. There is a debate amongst scientists and managers on whether the current models that predict the distribution of Dreissenid mussels are accurate. Recently for example veligers have been detected in Colorado lakes some of which have low calcium levels. Furthermore, a study in Lake George (NY) suggests that adult mussels are able to grow under low calcium conditions. However, the veliger recruitment determined from settlement bioassays is likely limiting. Thus, what will determine a source versus sink population may not be entirely clear and deserves some attention for Westem waters. A previous study using Lake Tahoe water by the PI suggests that adult quagga mussel fed low calcium, low algal biomass water may survive for greater than 50 days. Reproductive analysis showed that there was some evidence of gamete development in these mussels, but !indings were inconclusive as to whether mussel populations can maintain themselves in Lake Tahoe conditions. Survival ti?om the veliger stage to adult stage is key in the establishment of dreissenid mussels in any water body--this indicates the ability for species establishment after introduction. Current knowledge suggests that Lake Tahoe can support adult mussels for a short period of time however, whether juveniles, and thus a reproducing population can sustain is currently unknown. The proposed research will directly assess the habitat suitability of Lake Tahoe and its watershed to support the establishment of quagga mussel by testing the survivability of veliger to sub-adult stage using Lake Tahoe \Vater. This information will be important for supporting the current efforts related to inspection and washing of boats entering Lake Tahoe.