The recent discovery of 14 adult quagga mussels at Lake Powell is a crucial reminder to boaters to clean, drain and dry their boats after every use to help prevent the spread of these destructive invasive species.
According to a March 27 National Park Service (NPS) mussel monitoring update, the NPS identified 14 adult quagga mussels attached to moored vessels and dock structures at the Wahweap Marina in Lake Powell over the last week. None of the adult mussels were close enough together to mate for successful reproduction. All of the mussels were physically removed from the lake.
“At this point, these monitoring results aren’t evidence of an established, reproducing population of mussels,” says Tom McMahon, invasive species program coordinator for the Arizona Game and Fish Department. “NPS dive teams are continuing to check boats, docks and cables, and biologists are continuing to gather and assess information. In the meantime, boaters need to remember to clean, drain and dry their boat and equipment after every use.”
According to the NPS mussel monitoring update, the first four mussels were found when a local marine service business noticed the small shells on a boat that had been pulled for maintenance and then notified the NPS.
“We really appreciate the report of this finding since it will help in the removal of the adult mussels before they can reproduce,” said Mark Anderson, Glen Canyon ecologist, in the news release. “It’s likely that the mussels were introduced via ballast or bilge water from a boat(s) that was not cleaned, drained, or dried.”
Additional monitoring information and updates are posted on the Glen Canyon National Recreation Area webpage at www.nps.gov/glca.
McMahon emphasized that, under Arizona law, boaters who take their boats out of waters designated as having aquatic invasive species (this includes Lake Pleasant, Lake Mead, Lake Mohave and Lake Havasu) must take the following steps when leaving:
- CLEAN. Clean/remove any clinging material such as plants, animals and mud from the anchor, boat, motor, and trailer.
- DRAIN. Remove the plug and drain the water from the bilge, live-well and any other compartments that could hold water. Drain the water from the engine and engine cooling system(s).
- DRY. Ensure the watercraft, vehicle, equipment, or conveyance are allowed to dry completely.
- If you are using your boat again in less than five days from the previous use, replace the bilge drain plug and disinfect the bilge by pouring in not less than one gallon of vinegar; the vinegar can be drained from the bilge upon arrival at home (vinegar can be reused several times).
- If you’re taking your boat out of a lake where it has been moored more than five days, refer to the boat cleaning protocols for long-term users (view boat cleaning protocols in Director’s Order #3).
Quagga mussels colonize rapidly on hard surfaces and can ruin boat motors and clog water intake structures, such as pipes and screens, thereby impacting pumping capabilities for power and water treatment plants.
For more information on quagga mussels and other aquatic invasive species, including links to the Director’s Orders that list the species, the Arizona waters that have them, and the boat transport protocols from those waters, visit www.azgfd.gov/ais.
Image courtesy Arizona Game and Fish Department