Glen Canyon Natiinal Recreation Area conducted an intensive four-day dive operation from June 10th to June 14th to assess the extent of quagga mussels in lower Lake Powell and to remove all existing mussels. A total of 36 divers and 73 support staff destroyed 235 mussels.
Microscopic veligers (larvae) were identified last November during routine water testing in the southern portion of the lake near Antelope Point Marina and Glen Canyon Dam. In March, employees of a local marine service business found four individual adult mussels on a boat that was pulled for maintenance at Wahweap Marina. The park dive team began a systematic search of both marinas and found 170 additional adult mussels.
Glen Canyon officials scheduled the multi-agency dive operation in June to do a focused search and removal of adult mussels, thereby decreasing their ability to reproduce.
"We really appreciate everyone’s contributions to this operation," said Superintendent Todd Brindle. “With cooperation from other National Park Service units as well as other agencies, we were able to concentrate our efforts and mitigate this situation as soon as possible.”
Divers located mussels on moored boats, docks, and breakwaters dispersed throughout both marinas, but did not find any large colonies of mussels. The mussels varied from the size of a pea to the size of a quarter, which suggests a range of different ages. The vast majority of mussels found were individuals. There were three instances of small groups of two to three mussels at Wahweap Marina.
Mussel infestations typically consist of thousands of individuals in close proximity. With no current indications of veligers (larvae), and with the removal of the adult mussels, park officials remain optimistic that the focused effort eliminated the possibility of a reproducing population.
The park will continue intense monitoring efforts with periodic dive operations by park staff throughout the year. Although inspections are currently focused on the southern end of the lake, other marinas and docks will be assessed in the future.
Superintendent Brindle wishes to thank Carlsbad Caverns National Park, Curecanti National Recreation Area, Death Valley National Park, Delaware Water Gap National Recreation Area, Grand Canyon National Park, Grand Teton National Park, Lake Mead National Recreation Area, and Lake Meredith National Recreation Area for contributing divers and support staff. Other participating agencies and partners included the following:
Bureau of Reclamation
US Coast Guard Auxiliary
US Fish and Wildlife Service
Arizona Game and Fish Department
Utah Division of Wildlife Resources
Utah Highway Patrol
Antelope Point Marina
Lake Powell Resorts and Marinas (Aramark)
Big Water Fire & Rescue
Coconino County Sheriff’s Office
Grand Staircase Escalante Partners
Additional information about the Quagga Mussel Blitz and mussel monitoring at Glen Canyon National Recreation Area is available at the "More Information" link below.