Fear of little mussel closes Crowley Lake spur

A spur access point in Mono County to Crowley Lake will close starting Friday to prevent watercraft potentially carrying Quagga (zebra) mussels from entering the lake.

The access will remain closed through Halloween, according to the Bureau of Land Management's Bishop Field Office.

To help prevent the spread of the invasive mussels that can impact fish and damage water systems, all boats entering Crowley Lake will be thoroughly inspected. Boats showing signs of contamination, or found to contain any water or debris that could harbor mussels, will not be allowed to launch into Crowley Lake. Boats that pass the inspection will be issued an inspection certification and allowed to launch, according to Anne Halford, BLM Bishop Field Office botanist.

For the convenience of eastern Sierra residents and visitors who want to boat on Crowley Lake during the opening of fishing season, the Los Angeles Department of Water and Power will operate pre-inspection stations during daylight hours beginning Thursday at the Vons/Kmart shopping center in Bishop, and at Crowley Lake South Landing.

Boat launching will only be permitted through the main gate at the South Landing. Boats will not be allowed to launch, and trailers will not be allowed to park at the North Landing, Wild Willie's Springs and Layton Springs areas. Once a boat has passed inspection, frequent users can make arrangements to store their boat on-site and will not be required to have it re-inspected unless it leaves the property.

"The Quagga mussel poses a significant threat to the fisheries of the eastern Sierra as well as to hydrologic infrastructures," said Halford. "The mussels are prodigious water filterers, removing substantial amounts of phytoplankton and suspended particulates from the water. By removing the phytoplankton, Quagga mussels in turn decrease the food source for zooplankton, therefore altering the food web," she explained.

In addition, the mussels accumulate organic pollutants within their tissues to levels more than 300,000 times greater than concentrations in the environment. These pollutants pass up the food chain and increase wildlife exposure to organic pollutants. The Quagga mussel's ability to rapidly colonize hard surfaces also causes serious economic problems. These organisms can clog water intake structures, such as pipes and screens, reducing pumping capabilities for power and water treatment plants. Recreation-based industries and activities can also be impacted, Halford said.

Under the closure, motor vehicles are prohibited in the area except for emergency and law enforcement personnel, and BLM and LADWP employees in the performance of an official duty.

For more information, contact Halford at (760) 872-5022.