"Everyone needs to take this as a warning to continue to clean, drain, and dry your boat and equipment after every use," Anderson said.
The first sign of a quagga mussel at Lake Powell showed up in a water sample in the summer of 2007. A series of tests after the discovery led to negative results of the species in the reservoir.
Several boats have been stopped at the boat launching ramps at Lake Powell in recent years with live mussels attached. All boats launching at Powell must undergo an inspection and possibly a decontamination before entering the water at the recreation area or face a fine.
The National Park Service thanked an observant marine service business worker for noticing the first four mussels on a boat that had been pulled up for maintenance. A dive team will continue to inspect boats, docks and cables for mussels in the Wahweap area.
The mussels have caused extensive damage across the country since landing in the Great Lakes decades ago. State officials estimate that an infestation in Utah could cost more than $15 million annually if the 6,000 miles of pipes and canals and numerous dams become coated with the creatures.
The mussels can also severely impact fisheries and aquatic life and tourism as a result of sharp shells lining the beaches of popular recreation areas.
Sand Hollow Reservoir in Washington County is the only other water in Utah listed as infested. That is due to the discovery of an adult quagga mussel found on a boat dock in May 2010. No evidence of other mussels has been found since.
How to decontaminate your boat from possible mussel contamination
Decontamination is the only way to stop the spread of these horrible mussels. It does not harm your boat. It can actually prevent damage to your boat by removing mussels that would clog pumps and hoses. There are two ways to decontaminate your boat after pulling it out of the water:
Clean, drain dry • Clean mud, plants, animals or other debris from your boat and equipment. Drain the ballast tanks, bilge, livewells and motor. Dry it out (seven days summer, 18 days spring/fall and 30 days in the winter) or freeze (three days).
Professional decontamination • An alternative method (generally a free service) available at many Utah waters. Certified personnel will wash your trailer and boat inside and out flushing your ballast tanks, bilge, livewells and motor with high-pressure, scalding (140° F) water. This method is effective and does not harm your boat.
Boaters in Utah are required to complete decontamination forms at reservoirs and can speed up the process by taking a Mussel-Aware Boater Program.