Aquatic Invasive Species can irreversibly harm the Lake Tahoe watershed.

About Aquatic Invasive Species

Aquatic invasive species (AIS) pose a serious threat to the recreational and natural resources of the Lake Tahoe watershed. AIS compete with native species and can increase algae growth that contributes to the decline of Lake Tahoe’s famous water clarity. AIS damage boats and gear by building up on rudders, hulls and paddles.

The most serious threats to streams and lakes in the Lake Tahoe Region not currently present are zebra, quagga, and golden mussels and hydrilla. Each of these invaders is spread through the transport of water and/or debris that can collect in cockpits and hatches, cling to outer hulls, rudders, and paddles, and even hide out on your gear.

Once AIS are introduced and establish a local population, they are extremely costly to control and often impossible to eradicate. For example, the Lake Mead community spends over $20 million a year to combat their quagga mussel infestation. The prevention of new AIS infestations is more effective and more economical than the control or eradication of an existing infestation.

Protect Lake Tahoe! Golden mussels, an invasive species never before seen in North America, were recently discovered nearby in California—threatening Lake Tahoe. Protect the lake: Clean, Drain, Dry your watercraft. Click here to learn more.
Invasive Plants
Golden Mussels

Credit CDWR

Quagga Mussel
New Zealand mudsnails

Credit: USGS

Asian Clams
Quagga Mussel Veligers

Credit: NPS

New Zealand mudsnails
Quagga and Zebra Mussels

Lake Mead

Zebra Mussels

Threats to Tahoe

Zebra and quagga mussels are spreading rapidly throughout the United States. These species travel between counties and states by attaching to watercraft and gear, which are then transported great distances by car, truck, or trailer. The adults and juvenile mussels will attach to any watercraft stored in contaminated water, and their microscopic young (a.k.a veligers) can survive the journey between waterbodies if there is standing water throughout the trip. Adult mussels cause significant damage to water utilities, recreational facilities and watercraft where they use a cement-like adhesive to attach and accumulate in catastrophic densities. 

Golden mussels, an invasive species never before seen in North America, were discovered nearby in California in October, 2024. This is a close threat to Lake Tahoe.

The following aquatic invasive species of concern are NOT currently in Lake Tahoe:

AIS Present in Lake Tahoe

New Zealand mudsnails are tiny mollusks originating from New Zealand. In September 2023, the species was detected on the South Shore of Lake Tahoe for the first time. The adults are roughly the size of a grain of rice. One female can clone herself 230 times every year, resulting in 2.7 billion snails in just 4 years. These snails outcompete native species and can starve popular native and game fish species.

This animal is often transported via clumps of mud and plant fragments stuck to boots, watercraft, or other gear that comes in contact with the water. They can survive up to 7 days in dry conditions and 50 days in damp conditions. Click here for more information regarding the New Zealand mudsnail detection, and how you can prevent the spread.

Asian clams are a species of freshwater clam originating from the Asian continent. They are filter feeders that feed primarily on algae from the sandy bottom of water bodies. Asian clams are linked to algae blooms and the destruction of local clam species, and their shells litter the shores of lakes in which they inhabit.

First found in the waters of Lake Tahoe in 2002, populations of Asian clams have rapidly expanded since 2008. Populations of Asian clams are concentrated along the South Shore of Lake Tahoe. Current control methods include using suppression mats to block dissolved oxygen and food from reaching the clams under the lake bottom.

Curlyleaf pondweed is an aquatic invasive plant that has established in locations along the South Shore or Lake Tahoe. Curlyleaf pondweed reproduces via turions, a small seed-like pocket that can lie dormant for years. 

Unchecked curlyleaf pondweed contributes to the thick mats in near shore areas, creating unnatural habitat that allows other non-native species to establish. This damage Lake Tahoe’s famous clarity. Thick aquatic plant growth hinders navigation and can tangle on rudders, hulls and paddles.

Eurasian watermilfoil exists in Lake Tahoe and several of its tributary streams.

Invasive aquatic plants threaten the abundant recreational opportunities and natural wonders Lake Tahoe offers. Aquatic weeds grow unchecked to produce thick mats in near shore areas that alter ecosystems and damage Lake Tahoe’s famous clarity. Thick aquatic plant growth hinders navigation and can tangle on rudders, hulls and paddles. This thick aquatic vegetation also provides an unnatural habitat that allows other non-native species to establish.

The following aquatic invasive species are currently in Lake Tahoe:

For more information, visit these useful links:

Threats to Tahoe

Golden Mussels

Golden mussels, an invasive species never before seen in North America, were discovered nearby in California in October, 2024. This is a close threat to Lake Tahoe.

Zebra and Quagga Mussels

Adult New Zealand mudsnails are about the size of a grain of rice. One female can clone herself 230 times every year, resulting in 2.7 billion snails in just 4 years.  In September 2023, the species was detected on the South Shore of Lake Tahoe for the first time.

This animal is often transported via clumps of mud and plant fragments stuck to boots, watercraft, or other gear that comes in contact with the water. Clean, Drain, and Dry thoroughly at the haul-out site to reduce the risk of transporting mudsnails. Click here for more information regarding the New Zealand mudsnail detection, and how you can prevent the spread.

AIS Present in Lake Tahoe

New Zealand Mudsnail

New Zealand mudsnails are tiny mollusks originating from New Zealand. In September 2023, the species was detected on the South Shore of Lake Tahoe for the first time. The adults are roughly the size of a grain of rice. One female can clone herself 230 times every year, resulting in 2.7 billion snails in just 4 years. These snails outcompete native species and can starve popular native and game fish species.

This animal is often transported via clumps of mud and plant fragments stuck to boots, watercraft, or other gear that comes in contact with the water. They can survive up to 7 days in dry conditions and 50 days in damp conditions. Click here for more information regarding the New Zealand mudsnail detection, and how you can prevent the spread.

Aquatic Weeds (Eurasian watermilfoil and Curlyleaf pondweed)

Unfortunately, non-native Eurasian watermilfoil and curlyleaf pondweed exist in Lake Tahoe and several of its tributary streams. We need your help to ensure these non-native weeds are not transferred from Lake Tahoe into Fallen Leaf Lake. Echo Lake, Spooner Lake or our regional streams.

Invasive aquatic plants threaten the abundant recreational opportunities and natural wonders Lake Tahoe offers. Aquatic weeds grow unchecked to produce thick mats in near shore areas that alter ecosystems and damage Lake Tahoe’s famous clarity. Thick aquatic plant growth hinders navigation and can tangle on rudders, hulls and paddles. This thick aquatic vegetation also provides an unnatural habitat that allows other non-native species to establish.

Asian Clams

Asian clams are a species of freshwater clam originating from the Asian continent. They are filter feeders that feed primarily on algae from the sandy bottom of water bodies. Asian clams are linked to algae blooms and the destruction of local clam species, and their shells litter the shores of lakes in which they inhabit.

First found in the waters of Lake Tahoe in 2002, populations of Asian clams have rapidly expanded since 2008. Populations of Asian clams are concentrated along the South Shore of Lake Tahoe. Current control methods include using suppression mats to block dissolved oxygen and food from reaching the clams under the lake bottom.

AIS Present in Lake Tahoe:

Not Present in Lake Tahoe

Protect Lake Tahoe! Clean, Drain, Dry.

Just a few extra minutes can make the difference in protecting your recreation experience.
AIS can hide almost anywhere, and adult mussels can live up to 30 days out of water! Clean, Drain, and Dry your watercraft and gear before and after every launch, and properly Dispose of any plants or debris you find.
Motorized watercraft:
Plan for your mandatory inspection. Arriving Clean, Drain, Dry will save you time and money. Start here.
Non-motorized watercraft:
Learn how to Clean, Drain, Dry by watching the 5-minute training video. Become a certified Tahoe Keeper.

Protect the entire Tahoe Basin.

Fallen Leaf, Echo, Angora, and Spooner Lakes, as well as many other regional lakes and streams in the Lake Tahoe Basin, are free of invasive species. Help us keep it that way! Clean, Drain, and Dry between every launch.

Make Clean, Drain, Dry a habit.