Lake Tahoe is not just a breathtaking destination; it is a vital ecosystem that sustains recreation, fuels tourism, and supports a diverse array of wildlife. However, its clarity and health are at risk from aquatic invasive species (AIS) – plants or animals that did not evolve naturally in Tahoe and lack native predators to keep their populations in check. Aquatic invasive plants like Eurasian watermilfoil and curlyleaf pondweed are already present in the Lake and can spread rapidly, choking waterways, degrading water quality, and threatening the Lake’s delicate balance. 

Once these invaders take hold, removing them becomes nearly impossible. That’s why early detection is critical, and it starts with the people who know and love Tahoe best: its residents, visitors, and local businesses. Through the Eyes on the Lake (EOL) program, community members can become citizen scientists, identifying and reporting AIS before infestations grow out of control. 

The Eyes on the Lake Program: A Community Effort 

Eyes on theLakeis a volunteer-fueled program run by Keep Tahoe Blue that provides free training to locals, visitors, and businesses. Participants learn how to spot and report invasive species, serving as Tahoe’s first line of defense against AIS. 

The program works because of strong community involvement. The League partners with other agencies, all major marinas, and many businesses operating on the water, helping ensure that staff, boaters, paddlers, and recreators know what to look for and how to report potential threats. 

Here are a few AIS “Most Wanted” that the Eyes on the Lake program wants to prevent from getting into, or spreading further in Lake Tahoe:  

• 🔹 Eurasian watermilfoil & curlyleaf pondweed – Currently the most prolific plant invaders in Tahoe. 
• 🔸 Zebra, quagga & golden mussels – Not yet in Tahoe but dangerously close, having been recently discovered in California’s Sacramento – San Joaquin Delta and therefore too close for comfort.

Why AIS Prevention Matters Now More Than Ever 

Invasive species don’t just impact one part of the Lake. They spread fast. Right now, AIS are a growing challenge in the shallow areas of the Tahoe Keys, but without vigilant monitoring and action, they can reach every corner of Tahoe. 

Climate change is accelerating this problem. Warmer water and shifting precipitation patterns are making the Lake more hospitable for invasive species, allowing them to outcompete Tahoe’s native aquatic plants. 

Once AIS establish themselves, they: 

• Clog waterways, making recreation more difficult 
• Reduce habitat for native fish and wildlife 
• Threaten to turn Tahoe’s famously blue water to a murky green

The most effective way to protect Tahoe is early detection and rapid response, and that depends on the community stepping up to help. 

How Your Reports Make an Impact 

Keep Tahoe Blue’s scientists and other water quality managers can’t be everywhere simultaneously. Thankfully, trained volunteers enthusiastically fill the gap. Reports submitted by members of the public through the Citizen Science Tahoe App are reviewed by Keep Tahoe Blue and sent to proper environmental agencies like the Tahoe Regional Planning Agency (TRPA), Tahoe Resource Conservation District, California Department of Fish and Wildlife, and the U.S. Forest Service. These agencies use the data to track infestations, coordinate rapid response efforts, and prioritize future removal projects – ensuring that invasive species don’t take hold in new areas. 

What happens after you submit a report? 

• ✅ The League’s science team reviews and verifies the sighting. 
• ✅ If the report is in a new area or a previously managed site, it is escalated for action. 
• ✅ Data is added to the Citizen Science Tahoe live-updating map. 
• ✅ Data is shared with land managers and agency partners to prioritize removal and mitigation efforts. 

Every report contributes to a live-updating map used by scientists, agencies, and conservationists to monitor the spread of aquatic invasive species. You can explore real-time Eyes on the Lake data here: Citizen Science Tahoe Live Map. 

How to Get Involved & Make an Impact 

Join Eyes on the Lake and help protect Lake Tahoe’s waters. Whether you’re confirming the presence of invasive species or reporting an AIS-free area, every observation plays a crucial role in preserving the Lake’s clarity. Eyes on the Lake trainings are free and open to all ages and skill levels – anyone can make a difference in a few easy steps: 

1. Become a trained Eyes on the Lake volunteer – Free trainings teach how to spot and report AIS. 
2. Use the Citizen Science Tahoe web app – Submit reports in real-time; no downloads necessary. 
3. Spread the word – Encourage businesses, tour operators, and marinas to join the effort. 

• 📍 Eyes on the Lake trainings begin in June.  
  • View upcoming trainings 
• 🌐 Report AIS through the Citizen Science Tahoe web app 
  • Submit a sighting 
  • View Eyes on the Lake reports 

Businesses & Marinas: Join the Effort 

Businesses operating on the water play a key role in preventing the spread of invasive species. Tour operators, marinas, and rental companies interact with thousands of visitors each season and can help educate their customers. 

If you own or manage a business that operates on the water, email protect@ktb.org to get involved. The League provides free training and materials to ensure your staff can recognize and report AIS, helping keep Tahoe’s waters clean and clear. 

Snapshot Day: A Connected Effort to Protect Water Quality 

Eyes on the Lake is just one part of a broader citizen science movement working to protect Tahoe’s waters. Each May, volunteers gather for the annual Snapshot Day, Tahoe’s longest-running water quality monitoring event. 

During this free one-day event, participants collect samples from streams, lakes, and rivers, tracking pollution levels and providing valuable data to researchers. This data helps scientists understand how Tahoe’s water quality is changing and where intervention is needed. 

• Upcoming Snapshot Day: May 10, 2025 
• 📝 Sign Up for Snapshot Day 
• Check out the 2024 Snapshot Day Report & Interactive Web Map

Protecting Tahoe’s Future, Together 

Eyes on the Lake is successful because of you. By getting involved—whether by attending a training, reporting an AIS sighting, or encouraging your favorite Tahoe business to participate—you become part of the solution. 

The League’s Community Engagement Team also works with youth programs through the Blue Schools and the South Tahoe Environmental Education Coalition (STEEC) to train the next generation of Lake stewards. With every new volunteer, Tahoe gains another defender. 

Become a trained citizen scientist and help Keep Tahoe Blue.