Reclamation Information Sharing Environment (RISE)

Invasive quagga mussels have been present in the Lake Havasu ecosystem since at least 2007. Mussels are known to impact plankton communities, nutrient loads, macrophyte coverage, and higher organisms. This study was initiated to evaluate existing data related to ecological impacts of mussels at Lake Havasu. Data included water quality measurements and plankton survey data. No large trends were observed in the available data. Plankton communities have changed slightly, with rotifers becoming a larger percentage of the biomass. Soluble phosphorus may be shifting to deeper water, while nitrate-nitrogen and chlorophyll concentrations appear to have increased. Developing a full picture of the ecological impacts at Lake Havasu will require a standardized, long-term monitoring program that includes water quality and plankton, as well as higher organisms like fish and macroinvertebrates.