New test results indicate the presence of an extremely small number of individual, larval Quagga or zebra mussels in Lake Powell. Two cooperative research and monitoring efforts, conducted on July 19 and 30 by the U.S. Geological Survey, the National Park Service, and the Utah Division of Wildlife Resources, detected three individual mussel larvae at the Wawheap marina and near the Glen Canyon Dam.
Dr. David Britton, an expert on Quagga and zebra mussels for the U.S. Fish and Wildlife Service, said, "While the test results indicate the presence of individual larval Quagga or zebra mussels in Lake Powell, much uncertainty remains. We do not know at this point if an established population is present. We also do not know for certain how Quagga or zebra mussels will affect Lake Powell."
Five water samples were collected from Lake Powell and analyzed by a Bureau of Reclamation laboratory in Denver. The samples were analyzed using two different methods - a microscopic technique and DNA fingerprint technology. Three of these samples did not indicate the presence of any Quagga or zebra mussels. Two of the samples, collected at the Wahweap Marina and near the Glen Canyon Dam, indicated the presence of three individual larval mussels when tested with the microscopic method and DNA fingerprint technology. The testing methods cannot distinguish whether or not these are Quagga mussels or zebra mussels, which are closely related.
"Additional samples have been collected from Lake Powell and are being analyzed for Quagga and zebra mussels. In the coming weeks, more samples will be collected from various locations around the lake to determine if mussels are present in other areas," said Kitty Roberts, superintendent of Glen Canyon National Recreation Area.
The National Park Service, Utah Division of Wildlife Resources, Arizona Game and Fish Department, Bureau of Reclamation, and U.S. Fish and Wildlife Service have been closely working with each other to closely monitor the spread of Quagga mussels since they were found in Lake Mead in January 2007.
The National Park Service's existing Quagga and zebra mussel prevention program will remain in place. Boats that have been in water bodies with known Quagga or zebra mussel infestations in the last 30 days will continue be required to be decontaminated before entering Lake Powell. High pressure, hot water decontamination stations are available at all marinas within Glen Canyon National Recreation Area, including Wahweap, Antelope Point, Bullfrog, and Halls Crossing marinas.
As a preventative measure, the National Park Service will also begin requiring any boats that are slipped in Lake Powell to receive a decontamination wash before they exit the park if they are being moved to a non-infested lake. In addition, people with boats in the marinas at Lake Powell are strongly encouraged to conduct a thorough inspection of their boat to look for Quagga or zebra mussels which may be attached.
To prevent Quagga mussels or any other aquatic nuisance species from being spread to other lakes, all visitors leaving