Mussel Frequently Asked Questions
FAQ: Quagga Mussel Update for Lake Powell 5/23/2014
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1. What is the status of quagga mussels in Lake Powell?
A reproducing population of quagga mussels exists in the southern portion of Lake Powell. Adult mussels in the area are sparse near the surface, but their numbers are expected to increase at a high rate and the population is expected to expand throughout the lake. Two adult quagga mussels have been found near Bullfrog and could indicate reproduction; however, no other indications of an infestation have been found near Bullfrog area.
2. Are quagga mussels in the river below the dam?
As the quagga mussel population in Lake Powell increases over time, veligers (mussel larvae) are expected to pass through the dam. Veligers that reach the river will seek to attach to hard surfaces in low flow areas. They are not expected to reach high numbers due to the speed of the current and the muddy water. Canals of the Central Arizona Project have not yet developed large populations of mussels despite veligers being delivered from the Lower Colorado River.
3. Can the NPS eliminate or stop the spread of mussels within Lake Powell?
There are no current technologies or treatments that would allow for eradication of the initial population in an open water environment the size of Lake Powell. Options to slow the spread of mussels within Lake Powell, such as restrictions on boat movements, were considered. However, due to questionable efficacy, significant disruption to visitors and lake operations, and the difficulty of enforcing restrictions, these options will not be implemented. Veligers are also dispersed upstream by wind-generated currents and are expected to colonize the entire reservoir.
4. What changes will occur for boaters now that mussels exist at Lake Powell?
The Aquatic Invasive Species (AIS) Program at Glen Canyon National Recreation Area will transition from a focus on prevention of mussels being introduced into the lake, to a focus on containing the spread of quagga mussels from Lake Powell to other bodies of water.
5. Will different types of boats be treated differently?
The NPS identified and ranked the relative risks of different pathways for both the introduction of aquatic invasive species to Lake Powell and the potential spread of quagga mussels from Lake Powell. For spread of adult mussels, long-term slipped and moored watercraft were identified as a high risk vector. Short-term come-and-go watercraft were identified as a relatively low risk for spreading adult mussels; however, they can still potentially spread veligers.
ALL VESSELS AND EQUIPMENT BEFORE LAUNCHING: Required self-decontamination (Clean, Drain, and Dry). If visible mussels or other invasive species are identified the vessel will be prevented from launching until the threat can be removed.
ALL VESSELS AND EQUIPMENT BEFORE LEAVING: Required self-decontamination—Clean and Drain before leaving the area; Dry before re-launch. Professional decontamination will be required if the boat is going to be launched without adequate dry time. (See state laws for specifics).
SLIPPED AND MOORED VESSELS: Required to be inspected and if necessary, professionally decontaminated in accordance with Arizona and Utah state laws.
COMMERCIAL ACTIVITY (permit holders, commercial businesses that operate in the park, contractors): Required to be inspected and if necessary, professionally decontaminated in accordance with Arizona and Utah state laws. This requirement will apply to agency controlled watercraft upon exit from Lake Powell for transport to other waters. This will be managed as a concessioner, contractor, and permittee responsibility as law and policy allow.
6. Where can boats get a hot wash or decontamination?
For the 2014 boating season, Glen Canyon will offer decontamination services for any non-agency-controlled vessel (other than concessioner, contractor, permittee) observed entering or exiting the park with confirmed visible (or detectable) attached quagga mussels. Glen Canyon National Recreation Area does not have the infrastructure or the resources to use the few existing NPS decontamination stations for the hundreds of thousands of watercraft using Lake Powell.
The NPS will work with local entities to increase inspection and decontamination capability to serve Lake Powell boaters. If self-decontamination will not work for a visiting boater, professional decontamination is available from several private businesses near Lake Powell as well as state operated facilities in Utah. NPS employees as well as staff from the states of Utah (http://wildlife.utah.gov/mussels/decon_units.php) and Arizona (http://www.azgfd.gov/ais) can provide information on professional decontamination services, when necessary.
7. What is the NPS doing to stop the spread of mussels to other lakes and rivers?
The invasive species education program will be expanded to include additional information on the procedures required by both Utah and Arizona state laws concerning mussels and other invasive species.
8. What has the NPS done to slow the introduction of mussels into Lake Powell?
The NPS has operated a mussel prevention program at Lake Powell since 2000. To date, the approximate cost of the program has been over $7.5 million dollars.
9. What impacts could occur from mussels in Lake Powell?
Impacts from an invasive species in a new environment cannot be predicted with precision; however, mussel impacts are well documented and Lake Mead provides a relatively similar system to Lake Powell that can be used to anticipate impacts. Expected quagga mussel impacts include:
10. Are there other Aquatic Invasive Species (AIS) of concern for Lake Powell?
Even with quagga mussels already in Lake Powell, potential invasion by other aquatic invasive species are of concern. Zebra mussels (a close relative of quagga mussels) remain a threat to Lake Powell, as do a virtually unlimited number of other aquatic species that could be spread to the Lake. Any aquatic species that is transported to new waters can become a problem.
11. Are other agencies/partners helping to control the spread of mussels?
Preventing the spread of mussels is everyone's responsibility. Glen Canyon National Recreation Area participates in meetings with approximately twenty partner organizations representing local, state, and federal entities and businesses to coordinate mussel prevention and containment efforts at Lake Powell. The states of Utah and Arizona have established laws and regulations to prevent the spread of mussels; begun development of inspection and decontamination capability across the states; and mounted aggressive education campaigns. Other Department of Interior agencies, such as the Bureau of Reclamation and the U.S. Fish and Wildlife Service are very active with research to control mussels, educate boaters, and fund efforts to stop the spread.
12. What can the public do to help? How can boaters find information on the new state regulations?
Did You Know?
Personal watercraft are vessels. In Utah, you must be 18 years old to operate a personal watercraft alone (unless you comply with Utah personal watercraft operator conditions); in Arizona, you must be at least 12.