Although small in size, quagga mussels are causing big problems.
No larger than a quarter when full grown, the mussels are invading Lake Mead at an alarming rate. Trillions of the tiny invaders are now clogging water pipelines, attaching to boats and lake structures, and changing the lake's ecosystem at a cost of millions each year. And the invasion has been swift; the first mussels were discovered in the lake just two years ago.
Help for Water Managers
UNLV researchers, working with the National Park Service and its partners, have assembled the first standardized monitoring plan to track mussel size, abundance, and distribution at more than 50 sampling sites throughout the lake. Strategic monitoring will help lake managers understand how the mussels are changing the lake's ecosystem and affecting resources, such as Southern Nevada's drinking water supply.
"In a large natural ecosystem like Lake Mead, it's impossible to fully eradicate quagga mussels," said David Wong, UNLV professor and the project's lead investigator. "Once we identify how mussels behave given the lake's unique temperature, food sources, and existing biodiversity, we can develop appropriate ways to minimize their substantial environmental and monetary impact."
Impact on Drinking Water Supply
The mussels may be squeezing out the primary food source for top game fish. Also, their affect on the lake's biodiversity could potentially lead to the production of harmful toxins that impact drinking water supplies.
The quagga mussels were discovered in Lake Mead in January 2007, although it is unsure how the were initially brought to the lake. It was the first known occurrence of the species in the western United States. The invasive species' hold on Lake Mead is more alarming to researchers than their discovery in the Great Lakes in the late 1980s. Warmer water temperatures here allow for rapid, year-round reproduction.
Mussel sampling sites, which will be collected and analyzed at three-month intervals and logged into a tracking database, will be located on the lake floor's rocky, sandy, and muddy surfaces. The database will provide a clearer estimation of the Lake Mead invasion and can also be used by water managers throughout the West facing similar situations. The plan, which formally goes into effect later this summer, also incorporates tracking strategies for quagga mussel larvae, known as veligers.
"My hope is that the quagga mussel population reaches a threshold that finally limits their capacity in Lake Mead," said Wong. "Be it space, food, disease, or chemical factors, there must be some factor that limits their growth - and we intend to find it."
In addition to Wong, UNLV researchers include:
- Shawn Gerstenberger, professor of environmental and occupational health
- Craig Palmer, research professor for the Harry Reid Center
- Jennell Miller, program coordinator for the UNLV Public Lands Institute
- Graduate research assistants Sarah Mueting and Eric Loomis
Agencies involved in the creation and implementation of the monitoring plan include:
- National Park Service (Lake Mead National Recreation Area)
- Bureau of Reclamation
- Southern Nevada Water Authority
- Nevada Department of Wildlife
- Clean Water Coalition
- U.S. Geological Survey
- U.S. Fish and Wildlife Service