Tahoe’s response to the rising problem of aquatic invasive species is a program aimed at reducing risk of new species establishment and controlling invasive species already present.
There are twenty known non-native aquatic species in the Tahoe region. More than half are considered invasive. An invasive species is one that is “non-native to the ecosystem and whose introduction causes, or is likely to cause, economic or environmental harm or harm to human health” (National Invasive Species Council [NISC] 2008). 1 How did these non-native species get to Tahoe? Some were introduced intentionally; for example, to create fisheries. Other invasive species were introduced unintentionally through recreational activities and the dumping of household aquarium water. The bottom line is that the interconnection of modern global society brings with it the unprecedented movement and establishment of species around the world. Tahoe is in company with the rest of the world in facing the problems posed by aquatic invasive species.
Non-native species have been in Lake Tahoe Basin waters for over a century but the stakes are rising at present because both circumstance and public understanding are rapidly changing. Non-native fish and crayfish have resided in Tahoe for decades. The weeds Curlyleaf pondweed and Eurasian watermilfoil were first observed in the Lake less than twenty years ago. Asian clams were first observed in the Lake in 2007. Though invasive species have been present in Basin waters for some time, the rate of introduction has increased. At the same time, long-time non-native resident populations are, in combination with other factors, associated with changes heretofore unseen, most of these in Tahoe’s nearshore. In the most-recent decade awareness has grown of these species’ potential ability to bring about harmful change to ecosystems, biodiversity, health, economics or other aspects of human welfare. Public awareness has also increased regarding the threat of introduction of aquatic invasive species that are known to wreak havoc on ecosystems—such as quagga and zebra mussels.
Tahoe is responding to the rising threat of introduction of new aquatic invasive species and the problem of existing aquatic invasive species with the Lake Tahoe Basin Aquatic Invasive Species Program. This is an interagency effort deploying the resources and expertise of the private sector and local, state and federal agencies in a threefold effort. First, the Program aims to reduce the risk of new species introduction; Second to reduce the amount and impact of aquatic invasive species already in Basin waters; Third, to collect data and build knowledge about the changes aquatic invasive species may be instigating and what effect, if any, our efforts to stop them may be having. Though the Program, now in its fourth year, is lauded as a success, the question persists; Is it sufficient to prevent and combat aquatic invasive species effectively?
USACE. 2009. Lake Tahoe Aquatic Invasive Species Management Plan, California and Nevada. 120pp.
Global Invasive Species Programme (GISP). McNeely, Mooney, Neville, Schei and Waage. 2000. Global Strategy on Invasive Alien Species. 58pp.
Protect Your Waters
Tahoe Resource Conservation District
Aquatic Nuisance Species Task Force
California Department of Fish and Game, Invasive Species Program