Dear Sierra Club members and friends of Lake Tahoe:


We have written multiple messages to you before expressing the need to protect Lake Tahoe from a variety of impacts, most often tied to development or land management strategies.  However, there is yet another threat to Lake Tahoe, and her surrounding sister lakes, that requires our immediate and full attention:  “Aquatic Invasive Species.”  In other words, there are plants and aquatic species that live in lakes and water bodies that are not native to the Basin but can be brought here and if this happens, it will no doubt cause extensive harm.  According to the CA Fish & Game[1],

QuaggaQuagga mussel infestation can potentially lead to the closure of boating in affected waterways. They also wreak havoc with the environment, disrupting the natural food chain and releasing toxins that affect other species. Spread of the Quagga could result in millions of dollars in damage to water transport facilities.                                 



Text Box: Top: Zebra Mussel, Bottom: Quagga Mussel.  Left

The Problem:

You may have heard of Invasive “Mussels.”  In fact, you may have seen billboards, commercials and other educational materials this year talking about boat inspections, with references to preventing ‘hitchhikers’ from entering Lake Tahoe.  These are all part of an extensive multi-agency and organization campaign aimed at preventing the introduction of these invasive mussels (Quagga and Zebra Mussels) to Lake Tahoe and her Zebra Musselssurrounding water bodies.


The Consequences:

Environment & Economy:

Invasive mussels cause extensive resource and economic damage to our environment and economy (and our watercraft – read more below).  Environmentally, mussels compete with native species (and over time, they “win”) thus forever changing the native aquatic ecosystems in our Lakes.  They attach to just about anything – including each other (they can form 1 foot ‘clumps’).  In fact, mussel densities of over 1 million per square meter have been recorded in parts of Lake Erie.[2]  In terms of our beaches, mussel invasions can result in beaches made unusable due to razor sharp shells and a horrible stench.  


Examples of major resource damage and the costs involved with mitigating the impacts include:

-          In 1989 the town of Monroe, Michigan lost its water supply for three days due to massive numbers of zebra mussels clogging the city’s water-intake pipeline.

-          Swimming areas in Lake Erie have had increased costs associated with removing tons of mussel shell that wash up on beaches during storms.

-          Maintenance of pipes clogged with zebra mussels costs the power industry up to $60 million per year and temporary shutdowns due to insufficient water flow can cost over $5,000 per hour.

-          The U.S. Fish and Wildlife Service estimates the potential economic impact at $5 billion from 2000 to 2010 to U.S. and Canadian water users within the Great Lakes region alone.

-          U.S. Congressional researchers estimated that an infestation of the closely-related zebra mussel in the Great Lakes area…[creates an] economic impact to industries, businesses, and communities of more than $5 billion.

-          California could spend hundreds of millions of dollars protecting the state’s water system from a quagga/zebra infestation[3]. 

Beach covered with Mussels.



In addition to significant and irreversible environmental damage, imagine the economic costs if this happened in the Tahoe Basin.  We’d start with potentially millions of dollars related to infrastructure needs.  But further, if tourists can’t enjoy Tahoe’s shoreline because it’s covered with millions of shells, how will that affect an economy that depends on millions of visitors per year?  The environmental and economic impacts to the Basin would be devastating.


Why There’s No Going Back…

Once even ONE watercraft (or any water equipment) brings these mussels into our Lake, it’s too late.  There is no way to eradicate them.  They multiple, feeding off of native species, destroying the natural aquatic systems that are necessary for our Lake to thrive, and clogging up our beaches, water lines, boats and basically anything that touches Lake Tahoe or her shoreline.  There is no way to eradicate them with today’s technology.  Some have attempted chemical eradication, but because of their high tolerance, the chemicals that might work would poison everything in the water body.  Those managing other water bodies dealing with these invasives find themselves spending millions of dollars a year just to try to mitigate some of the impacts of these invasives – that’s all they can do, since there’s no way to reverse their introduction to an area.  This is why we must be extremely careful in our use and enjoyment of Lake Tahoe and her sister lakes (e.g. Fallen Leaf Lake). 


Using boats and equipment in areas that are infested, then using them in other lakes/water bodies is how these spread west in the first place.  Not only have the mussels made their way to California, but last summer there were 4 infested boats found at the agricultural inspection station in Truckee, CAone of those boats was headed for Lake Tahoe.



Text Box: Zebra Mussels Impacting Water Intake (USGS)



It’s not just about motorboats or boat launch inspections:

While it may be common to assume that larger boats – basically those that require boat launches to enter the Lake – are the potential problem, this is not true.  These mussels can reside on anything that touches a water body: kayaks, canoes, rafts, tubes, etc., including things we wear, such as scuba-diving gear or beach shoes (even our pets).  However, using these other types of recreational equipment may not require a boat launch, and therefore, equipment will not be subject to inspections prior to entering Lake Tahoe nor will users have the ability to talk to inspectors prior to launching. 


The ONLY way we can protect Lake Tahoe from these invasives is to

help prevent their introduction by taking action ourselves and

getting other recreationalists to do the same.




***** Read below to learn HOW you can help ****


If you own a recreational boat, kayak or canoe*:

Mussels damage boats and equipment.  According to the CA Fish and Game1, Quagga mussels affect boaters Go to fullsize imagenegatively because they:

·         Ruin your engine by blocking the cooling system - causing overheating.

·         Increase drag on the bottom of your boat, reducing speed and wasting fuel.

·         Jam steering equipment on boats.

·         Require scraping and repainting of boat bottoms.

·         Colonize all underwater substrates such as boat ramps, docks, lines and other underwater surfaces requiring constant cleaning.


What you can do:

1.         First and foremost, the best thing you can do is only use your boat in Lake Tahoe.

2.         Another lake-saving option is to save the fuel, launching and other costs of bringing your boat to the Basin and instead, rent a boat from local retailers.

                        3.         If these are not feasible options, then at a minimum, do the following: 

                              * Kayakers, canoers, etc.  use those steps below which apply to your vessel.

  • Inspect all exposed surfaces - small mussels feel like sandpaper to the touch.
  • Wash the hull of each watercraft thoroughly, preferably with high pressure/hot water. (140o F water is advised in most literature)
  • Remove all plants and animal material.
  • Drain all water and dry all areas.
  • Drain and dry the lower outboard unit.
  • Clean and dry all live-wells.
  • Empty and dry any buckets.
  • Dispose of all bait in the trash.
  • Inspecting a Boat.  CA Fish & Game3

    Wait (see below for how long) and keep watercraft dry between launches into different fresh waters.



One of the most detailed list of instructions we found for boat owners is at:


An Inspiration rebreather seen from the frontIf you own a raft, tube, scuba gear, etc.:

1.         As with boats, the best option is to only use your equipment in Lake Tahoe. 

2.         Another lake-saving option is to rent your rafting, tubing, scuba-diving and other water gear from local Basin


3.         Otherwise, see these procedures recommended by the CA Fish & Game:[4]

Quagga Mussel Diver Decontamination Protocols*

Diving Equipment:

1.             Check all gear that could potentially hide any veligers[5] (include regulators, BCDs, wetsuits, masks, snorkels and any other dive gear),

2.             Thoroughly clean all regulators, BCDs, wetsuits, masks, snorkels and any other dive gear, making sure to clean both the inside and outside of the BCD

to ensure that no mud or organic matter is present – use a brush if necessary.

3.             After cleaning, rinse your suit, equipment and inside of BCD with hot (<40° C or 104°F) or salt (1/2 cup salt/gallon) water. Note, if you use the salt-water

solution, it is very important to thoroughly rinse the equipment in freshwater after your cleaning because the salt crystals can harm your equipment.

4.             Allow gear, suit and other equipment to dry before diving in different waters. Veligers can survive for a period of time on wet scuba gear;

5.             Consider using two sets of gear if applicable, alternating between set every other day.

6.             If feasible, consider freezing your equipment overnight to kill any veligers.


Sampling equipment (nets, waders, boots, buckets, etc.):

1.             All field equipment needs to be visually inspected and all visible mussels removed and killed.

2.             All field equipment must be cleaned by soaking, dipping in, or scrubbing with a salt water solution. If one of these approaches is not possible, the

equipment should ideally be pressure-washed or at least rinsed with water (hot and/or high pressure if possible) and allowed to dry completely before

next use.

3.             Particular attention should be given to places where the mussels could be accidentally trapped, such as the treads of boots and waders, hinges of

benthic grabs, etc.

4.             If feasible, consider freezing your equipment overnight to kill any veligers.Make sure rafts and other materials are dry before rolling them up. 


* These are instructions for divers researching mussels but the same concepts apply to all equipment and clothing used in lakes.



People and Pets:

Additionally, although the risk is low, people and pets can possibly transport larvae. It’s a good idea to clean personal belongings and clothes that have been in contact with the water. It’s also a good idea to wash dogs and other pets that have been in the water. Brush their coats and dry them.


How long you should wait in between using your boat/equipment in other Lakes before entering Lake Tahoe: 

If a boat moved from a zebra-mussel infested area will be launched in waters that are not infested with zebra mussels, the general recommendation is to keep the boat out of water and let it dry for a minimum of 30 days after cleaning all equipment and draining all possible sources of standing water. However, such "quarantine" times may be reduced depending on local temperatures and relative humidities (this may explain the range of suggested “dry-out” periods found throughout the literature, however, 30 days is the longest and thus safest time period). 

-          To see the recommendations for the area you’ve used your boat in, visit this website and plug in the month and location:


We recommend you watch this video (“Don’t Move a Mussel: Part 1”):


For additional information, visit:



SPREAD THE WORD, NOT THE MUSSELS!!!  We have a lake to save.  And a way of life.


Thank you.


The Tahoe Area Sierra Club Group


[4]  (Click on “Diver Decontamination Protocols”)

[5] A Veliger is a juvenile (larvae) form of quagga mussels that is extremely small (smaller than the diameter of a human hair) and ‘floats’ in water.