Guest View: Let’s keep Tahoe a mussel-free zone
It should come as no surprise to people that a number of aquatic invasive species already exist in Lake Tahoe. Invasive plants such as the Eurasian watermilfoil and the curlyleaf pondweed have established themselves in some areas of the lake. Plants like these negatively affect the lake in many ways, including providing habitat for other invaders such as warm-water fish like blue gill and largemouth bass. These fish are voracious eaters that prey on native minnows and compete with native species for food. Milfoil in particular has taken hold in the Tahoe Keys, where ongoing efforts to control it cost hundreds of thousands of dollars per year.
Efforts to eradicate milfoil are under way in locations around the lake, using techniques such as hand pulling, suction dredging and bottom barriers. As eradication efforts in the near future shift to areas of greater infestation such as the Tahoe Keys, the use of new methods will need to be explored.
Recently, however, our focus has been on more than just eradication of the exotic pests already inhabiting the lake. We are equally concerned with preventing those that have not reached the lake from getting here. This includes such creatures as the New Zealand mud snail, which is present in the American River and Mono Basin. It also includes quagga and zebra mussels, which came from Asia to the Great Lakes in the late 1980s and have established themselves in waterways and waterworks across the United States, with disastrous results.
Quagga and zebra mussels are of grave concern. Their detection in the Mississippi River in 1995; at Lake Mead, Lake Havasu, Lake Mohave and the Hoover Dam in 2007; and most recently at San Justo Reservoir in San Benito County, about 250 miles from Lake Tahoe, have shown these invaders to be persistent, resilient and destructive. Since their detection in San Justo, officials have banned watercraft from using the reservoir. As they spread to warmer climates, they multiply at a faster rate and adapt quickly to life in different habitats. Hoover Dam officials fear the mussels ultimately will begin clogging hydroelectric pumps. Unable to eradicate them completely, they may ultimately have to settle for budgeting $1 million per year to keep them at bay enough that they won’t clog their pumps and water-delivery systems. The small freshwater shellfish can easily adhere to boats and boat trailers, then survive for days out of the water. Once a contaminated boat enters a new waterway, the mussels can break free and begin reproducing with astonishing efficiency. Colonies of these mussels are efficient filter feeders that remove plankton from the water, disrupting the food web and touching off ecological collapse.
The threat is real, and Lake Tahoe region agencies are taking it seriously. This is why beginning this season, boaters visiting Lake Tahoe can expect to encounter inspectors, mussel-sniffing dogs and surveyors asking questions about where their vessels have been and how much time has elapsed since they last were in the water. Boat-washing stations will be available for those vessels requiring decontamination. This month, the TRPA Governing Board will consider changes to the TRPA code to prohibit the introduction of aquatic invasive species and to require that watercraft be subject to inspection. Also expect to see media coverage, warning signs and radio and television commercials – whatever we have to do to alert the boating public – commencing in the coming days and weeks.
In addition to being aware and cooperating with inspectors at the boat launches, there are things boaters can do on their own to help this effort along. Clean, drain and dry are the three words to remember to prevent the introduction of aquatic invaders.
— Clean: Wash your vessel before coming to the boat ramp to remove any attached invaders. Plant parts found on boats and trailers should be removed and disposed of away from the water.
— Drain and dry: Before leaving a water body, drain livewells, cooling water, bilge water, ballast and transom wells – that’s where these aquatic hitchhikers can stow away for your next boating day. Bait buckets also should be emptied on land, away from the water, and waders should be cleaned of mud and thoroughly dried.
We want to prevent quagga/zebra mussels and other invaders from hitching a ride to Lake Tahoe on your boat and trailer, and prevent those species that are in Lake Tahoe, such as milfoil, from spreading to other lakes. While the preventative measures we have to take to accomplish this may mean a few moments of inconvenience, we know the boating public will understand. Boaters come to Lake Tahoe because it is a special place, and they, like us, want to keep it that way. With cooperation and understanding, we know we will succeed.
– John Singlaub is executive director of the Tahoe Regional Planning Agency. For more information, visit http://www.trpa.org.