Aquatic Invasive Species Abundance
This indicator measures the abundance of aquatic invasive species (AIS) in Lake Tahoe. AIS are non-native organisms that threaten the abundance and diversity of native organisms in Lake Tahoe. Non-native species have been intentionally and unintentionally introduced to the Tahoe Basin over the last 150 years. This includes fish such as Lake Trout, mollusks such as Asian Clams, and plants such as Eurasian watermilfoil and curly-leaf pondweed. The presence of these species continues to threaten native taxa of the lake and is a nuisance to users of the lake. The presence of AIS also results in economic impacts for the Tahoe Region with potential costs to tourism, property owners, boaters, and maintenance. Watercraft inspection stations around the Region operate to prevent the introduction of new aquatic invasive species to Lake Tahoe, and there are numerous projects to remove existing AIS infestations. AIS abundance is monitored by TRPA and Environmental Improvement Program partners.
Status
Evaluation Map
Distribution of subsurface aquatic plants. Note that this includes both native and non-native subsurface aquatic plants.
2019 Evaluation
- Status
- Insufficient Data to Determine Status or No Target Established
- Trend
- Insufficient Data to Determine Trend
- Confidence
- High
Applicable Standard
WQ9: Reduce the abundance of known aquatic invasive species.
Key Points
- The first basin-wide survey of the extent of native and invasive aquatic plants was completed in 2020. Excluding the Tahoe Keys lagoons, the survey documented lakewide nearly 30 acres of Eurasian watermilfoil infestation and 8.8 acres of curly-leaf pondweed infestation.
- Invasive plants infest nearly 90 percent of the 170 acres of the Tahoe Keys lagoon channels.
- The treatment of 47 acres of AIS between 2016 to 2019 reduced the abundance of AIS lakewide. No trend determination is made because the 2020 survey is the first established baseline.
- Treatment plans are being developed for nearly every identified AIS infestation in Lake Tahoe.
Delivering and Measuring Success
Example EIP Projects
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Tahoe Keys Aquatic Invasive Plant Enhanced Fragment Control Pilot
This project at the west channel entrance works to prevent AIS plant fragments from spreading into Lake Tahoe. This includes skimming and collecting, boat back-up station, and a bubble curtain.
Local and Regional Plans
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Aquatic Invasive Species Action Agenda 2021-2030
The AIS Action Agenda identifies priority projects and establishes treatment goals for the next 10 years.