Lake Tahoe EIP

New Zealand Mudsnail Rapid Response

Project Number
01.03.01.0042
Action Priority
Prevent, Control, or Eradicate Aquatic Invasive Species
Implementers
Tahoe Regional Planning Agency, California Department of Fish and Wildlife, California Lahontan Regional Water Quality Control Board, Nevada Division of Environmental Protection, Nevada Tahoe Resource Team – Nevada Department of Wildlife, Tahoe Resource Conservation District, Tahoe Water Suppliers Association, U.S. Forest Service - Lake Tahoe Basin Management Unit, UC Davis Tahoe Environmental Research Center
Supporting Agencies
Tahoe Regional Planning Agency, U.S. Fish and Wildlife Service
Primary Contact
Emily Justice (ejustice@trpa.gov)

Stage
Implementation
Duration
2023 - 2025
Total Project Cost
$550,000
Funding Request
$0
Aquatic Invasive Species Program Prevent, Control, or Eradicate Aquatic Invasive Species
On 9/6/2023, invasive New Zealand mudsnails (NZMS) were discovered in areas off the South Shore by divers conducting aquatic invasive plant monitoring. Following rapid response protocols under the federally approved Lake Tahoe Aquatic Invasive Species Management Plan, TRPA convened an incident team comprised of staff from TRPA, Tahoe RCD, and partner experts and began rapid response actions: delineation, tracking spread, updating prevention procedures, expanded outreach and education, and researching management options. A technical advisory committee was formed to provide expertise. Actions to track and prevent spread have been incorporated into AIS program protocols.

Targeted Performance Measures

  • Acres of Invasive Species Inventoried
  • New Invasive Species Locations Detected
  • Watercraft Inspections for Invasive Species

Threshold Categories

  • Fisheries
  • Water Quality
Invasive New Zealand mudsnails on algae in Lake Tahoe. 
(Timing: During) (~1,363 KB)
Credit: Marine Taxonomic Services Invasive New Zealand mudsnails on algae in Lake Tahoe.

Location

Targeted Funding

Secured Funding: Lake Tahoe Restoration Act (TRPA), $150,000

Secured Funding: U.S. Fish and Wildlife Servi... (USFWS), $100,000

No Funding Source Identified

Photos

During
2024 Grid survey for New Zealand mudsnail.
(Timing: During) (~863 KB)
Credit: Tahoe Resource Conservation District
2024 Grid survey for New Zealand mudsnail.
2023 Grid Survey for New Zealand mudsnail.
(Timing: During) (~868 KB)
Credit: Tahoe Resource Conservation District
2023 Grid Survey for New Zealand mudsnail.
Roving Inspector educating beach goers and paddlers.
(Timing: During) (~3,821 KB)
Credit: Tahoe Regional Planning Agency
Roving Inspector educating beach goers and paddlers.
eDNA collection
(Timing: During) (~579 KB)
Credit: Nevada Division of Environmental Protection
eDNA collection
Invasive New Zealand mudsnails from Lake Tahoe under a microscope.
(Timing: During) (~534 KB)
Credit: Marine Taxonomic Services
Invasive New Zealand mudsnails from Lake Tahoe under a microscope.
New Zealand mudsnail size is about the size of a grain of rice.
(Timing: During) (~658 KB)
Credit: Marine Taxonomic Services
New Zealand mudsnail size is about the size of a grain of rice.

Project Fact Sheet Data as of 06/12/2025