Mussel-Infested Boat Quarantined at Glen Canyon Launch Area

Saturday, April 09 2011 10:29   Arizona
A vessel infested with live adult quagga mussels was prevented from launching on Lake Powell in Glen Canyon National Recreation Area on March 24 before the invasives could contaminate lake waters.

The mussels were discovered by an employee at Antelope Point Marina during a routine inspection. Park staff decontaminated the vessel and placed it in quarantine for 30 days to ensure that all associated mussels will die before it is launched.
glca_quaggasIn addition to the adult mussels found attached in small crevices on the hull and outdrives, numerous quagga mussel larvae (veligers) were detected in water held in the engine and other systems of the boat.

Movement was evident in the microscopic body masses within the tiny veliger shells during laboratory examination indicating that the veligers were alive, rangers said.

"These microscopic veligers are a real threat to Lake Powell," said Chief of Resource Management Chris Hughes. "This example reinforces our sense of duty and provides clear evidence that even water, while seemingly harmless to the naked eye, can have a huge impact on park resources."

The vessel had been moored in a lower Colorado River reservoir that is infested with quagga mussels, a type of invasive mussel commonly referred to as zebra mussels. The infested boat had received a decontamination treatment prior to leaving the lower Colorado reservoir, but it is nearly impossible to find and remove all of the mussels, rangers said.

At Lake Powell, the vessel was treated again and placed in quarantine for 30 days, assuring that all associated mussels will die. While quarantine is undoubtedly inconvenient for park visitors, keeping Lake Powell mussel-free is essential to maintaining the economic and ecological vitality of the resource and surrounding communities and region, rangers said.

Glen Canyon began a proactive zebra mussel prevention program in 1999 and continues to be one of the leaders in zebra mussel prevention in the western United States.

Since 2003, the park has required all vessels identified as having a high risk of transporting zebra mussels to Lake Powell to receive a specialized boat and equipment wash before launching in Lake Powell. This service is provided at the park for free.

Glen Canyon's program has been successful through these efforts combined with the cooperation of visitors, partner agencies and park concessioners.

"Hopefully this finding will help all boaters understand how important it is to clean, drain, and dry their vessels," said Chief of Aquatic Resources Mark Anderson.

Boaters are reminded to make sure that any vessels being moved from infested waters to non-infested waters are properly decontaminated prior to launching.

For additional information on Glen Canyon's efforts to keep Lake Powell mussel-free, visit Information on the impact of invasive mussels can be found at and