TRPA, according to its website "is charged with protecting this national treasure for the benefit of current and future generations. Our vision is to have a lake and environment that is clean, healthy and sustainable for the community and future generations." This job made more difficult, as I discussed in my last column by the "Tragedy of the Commons" phenomenon, whereby people who share a common resource tend, unless they are careful, to treat that resource as if it were theirs to do with as they wish. A case in point is the problem of invasive species.
During the last 130 years numerous non-native fish, invertebrate, and plant species have been introduced intentionally and unintentionally to Lake Tahoe. Each of these non-native species have had an effect on the environment of the lake. Those that were introduced by game and fish managers – trout, for example, have done well. Those introduced by what the professionals call "bucket biologists" – notably bass, bluegill, and other warm water species, have decimated certain native populations. It's the species introduced unintentionally or unintelligently that cause the problems. Eurasian water milfoil and Curly leaf pondweed took hold in Tahoe Keys and continue to proliferate there and in other areas such as Emerald Bay and need to be cut back. Currently Quagga and Zebra mussels pose a threat, and Asian Clams are established in the lake. The latter, while not as harmful as the mussels, provide a source of calcium which the mussels need to thrive and have been linked to algae blooms, etc. for example in Marla Bay.
Like the invasive plant species, the mussels are brought to the lake from other bodies of water. Lake Mead and Lake Havasu, for example, already host them. The only way they can get into Lake Tahoe is to be brought in by people – on powerboats, sailboats, jet skis, kayaks, canoes, etc., that have been in water where the mussels live. These species are famous for their ability to latch onto anything in the water, and they are then carried dormant for long periods – weeks in cold weather - unless they are taken off.
TRPA has launched a major effort in this regard. All the boat launching sites around the lake have inspectors and no craft can launch without being inspected and, if necessary, cleaned. But these inspections only cover boats that launch from trailers or are put into the water at marinas. What about the rest – the kayaks, canoes, and other craft that can launch from any lake access?
The key to all this, of course, is an educated public. Consideration has been given to creating education/inspection stations at the seven entrances to the Basin, but neither TRPA nor the conservation districts have the power to require cars to stop, so instead the agencies will work with the Forest Service to distribute literature and educate people at the launch sites, by material at the kiosks and information stations, etc. Ultimately, though, it will depend on people acting in the long-term interests of all rather than their own short-term convenience.
I mentioned in my last column one boater who went to several launch sites hoping to evade inspection. Why would someone do that? All the inspection does is protect the lake, and if they had to clean mussels from his boat, it would have taken less time and gas than going from launch site to launch site cost him. But nobody was going to make him submit to inspection! He had, in his mind, a right to use this shared resource, even if his use was to the detriment of the resource.
Last year only one boat was found to be contaminated with adult mussels at the inspection sites and one at the Ag station in Meyers. Twenty-five vessels that may have carried mussels were decontaminated as well. So far as we know, TRPA and other organizations have been successful in keeping the mussels out of the lake, but that won't continue as long as we who use the lake treat this like someone else's problem. Get the word out, support the education efforts, if you have visitors who bring kayaks or canoes have them check them carefully, and remember, the lake you save may be your own.