Battle To Keep Lake Powell Free of Quagga Mussels Continues At Glen Canyon National Recreation Area

The four-day dive blitz included divers and support staff from a number of agencies. NPS photo.

The battle to prevent quagga mussels from establishing a reproducing population in Lake Powell continued earlier this month with an intensive four-day search and destroy dive operation at the two major marinas on the lower end of the lake. Based on the results, officials at Glen Canyon National Recreation Area are optimistic the huge lake can still be kept free of an infestation.

If you're not sure why some tiny mollusks are causing such a stir, you'll find some answers in previous stories on the Traveler and on this site. Suffice it to say, efforts to keep them from spreading to new waterways are worth it.

The recent "dive blitz" at Lake Powell was prompted by news back in March that 14 adult mussels had been found at the Wahweap Marina, a major hub for boaters on the lake. Between June 10 and 14, federal, state and local agencies and other partners joined forces to conduct the intensive underwater sweep of the major marinas on lower Lake Powell.

A Major Multi-Agency Effort

A total of 36 divers and 73 support staff participated in the project, which had two main goals: assess the extent of quagga mussels in lower Lake Powell, and remove all existing mussels. The outcome could be described as a classic case of both good news and bad.

On day one, June 10, divers found and removed 138 mussels at Antelope Point Marina. The second day yielded 63 mussels at Wahwep Marina, with an additional 22 of the creatures on June 12. On the final day, a dozen additional quagga were removed. The grand total for four days: 235 mussels.

According to a park spokesperson, 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.

Presence of Individual Mussels Rather Than Groups Was Good News

Although the presence of any quagga in the lake wasn't encouraging, there was some good news from the project. The vast majority of mussels found were individuals, although there were three instances of small groups of two to three mussels at Wahweap Marina.

That information is important, because infestations typically consist of thousands of individuals in close proximity; individual mussels can't reproduce, and even a few clusters of two or three individuals are unlikely to multiply.

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.

“We really appreciate everyone’s contributions to this operation. Fellow agencies, local businesses, and our visitors have all been supportive of the removal efforts,” said Superintendent Todd Brindle. “We could not have done this safely and efficiently without the cooperation of boaters. Everyone was patient with short delays and respectful of divers in the water.”

Boat Inspections and Certifications To Continue

Boat certifications and inspections will continue at Lake Powell, as well as underwater surveys and removal. 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.

The cooperation of boaters in preventing the introduction of quagga mussels into the lake continues to be the key part of the effort. If you're a boater and are planning a visit to the area, click here for details about the mandatory inspection program.

You'll also find more information about the quagga prevention program at Glen Canyon National Recreation Area at this link.