May 2007

National Park Service Specialists Target Exotic Mussels

DENVER — An NPS All Risk Incident Command Team has met in Fort Collins, Colo., to develop a plan to prevent the infestation of non-native quagga or zebra mussels at national park sites throughout the western United States.

Quagga mussels were first discovered in Lake Mead in January 2007. Lake Mead National Recreation Area has had an aquatic species prevention program in place since 2002. As part of that program, park and concession employees were trained in identification methods.

This allowed quick identification of the mussel and notification of other agencies, parks and states in the region. Quagga mussels have also been found in Lake Mohave and Lake Havasu.

The mussels are spread to other waters primarily by attaching to boats that have been launched in infested waters.

In response to the infestation at Lake Mead National Recreation Area, the park promptly implemented an initial-response plan to assess the extent of contamination, contain the existing infestation by requiring mandatory cleaning of slipped and moored boats, instituted new requirements for boat-hauling permittees, increased the availability of boat-washing facilities, and raised public awareness of how to avoid spreading quagga mussels into other waters by increasing signage in the park, and distributing thousands of information flyers to hundreds of regional marine businesses.

Glen Canyon National Recreation Area, located in southern Utah and northern Arizona, has had a zebra and quagga mussel prevention program in place since 1999 to prevent the exotic mussels from becoming established in Lake Powell. Given the recent discovery of quagga mussels in Lake Mead, Glen Canyon has expanded its prevention program.

The park is building additional decontamination facilities, staffing entrance stations for extended hours, and requiring boaters to certify that their vessels are free of mussels.

Both quagga and zebra mussels reproduce at incredible rates. Because they are microscopic as juveniles, they can be difficult to detect. Both quagga and zebra mussels filter large quantities of water, removing important food sources for other aquatic species.

They can destroy boat motors and clog water-intake pipes in reservoirs. In addition, beaches may become littered with rotting piles of dead mussels and the resulting shell debris. Neither species has a natural predator.

The discovery of quagga mussels at Lake Mead is the first known appearance of the invasive species in the western United States. Until the discovery at Lake Mead, zebra and quagga mussels were a problem primarily in Midwestern and eastern states.

The NPS Incident Management team that met in Fort Collins focused on preventing the spread of quagga mussels from Lake Mead. The best management practices employed for controlling quagga mussels will also prevent the spread of other aquatic invasives, preserving valuable water resources and recreational opportunities.

The National Park Service’s incident-management team will produce a plan for western national parks to prevent, promptly detect and rapidly respond to any appearance of quagga mussels and to prevent the damage to property and ecosystems that the mussels and other aquatic invasives can produce.

The contingency plan is expected to be completed by May 10. For further information contact Kevin Schneider, management assistant at Glen Canyon NRA, at (928) 608-6208.