Lake Powell’s mussel infestation continues to worsen

ST. GEORGE – The quagga mussel infestation at Lake Powell has exploded, according to state officials who say they have stopped significantly more mussel-infested boats from entering Utah waters this year compared to previous years. Many of those boats came from Lake Powell.

Quagga mussels at the Wahweap Marina at Lake Powell, date unspecified | Photo courtesy of the Utah Division of Wildlife Resources, St. George News

“The quagga situation at Lake Powell has worsened. If you boat at Lake Powell it’s very likely your boat has quagga mussels on it,” Nathan Owens, the Aquatic Invasive Species program coordinator for the Utah Department of Natural Resources, said in a press release Tuesday.

If this is your first time reading about quagga mussels – sometimes referred to as the “STD of the Sea” – and you’re wondering what they are and why they’re a problem, consider the following from the Utah Division of Wildlife Resources:

  • Mussels can plug water lines, even lines that are large in diameter.
  • If mussels get into water pipes in Utah, it will cost millions of dollars to try to remove them, and you’ll likely pay higher utility bills as a result.
  • Mussels remove plankton from the water, the same plankton that support fish in Utah. The mussels could devastate fisheries in Utah.
  • Mussels can get into your boat’s engine cooling system. Once they do, they’ll foul the system and damage the engine.
  • When mussels die in large numbers, they stink. And their sharp shells can cut your feet as you walk along the beaches where the mussels died.

Contaminated boats can be seized and quarantined depending on the circumstances. So far this year over 100 boats have been quarantined compared to fewer than 10 in 2017.

Lake Powell’s quagga mussel population has spread rapidly within the last year. This increase, as well as the lake’s lower water levels, are seen as possible reasons for the increase in contaminated boats.

“With more mussels in the lake and lower water levels more boaters have mussels attached to their vessels than in past years,” Owens said. “Our techs are regularly finding them on and in boats that have only been in Lake Powell for a day or two — something we haven’t experienced in the past.”

A Utah DWR AIS biologist examines a quagga mussel-encrusted boat dock at the Wahweap Marina at Lake Powell, date unspecified | Photo courtesy of the Utah Division of Wildlife Resources, St. George News

In response to the increased threat posed by the invasive mussel, boat inspections and decontaminations have increased.

As of July 30, technicians had inspected over 144,000 watercraft statewide and decontaminated 4,700. Last year overall, they inspected 130,000 watercraft and decontaminated 4,400.

So far this year, both state and National Park Service employees have inspected over 47,000 boats leaving Lake Powell and had to decontaminate 3,700 at the lake. In all of 2017, approximately 51,000 boats were inspected at Lake Powell, and roughly 2,500 were decontaminated.

Due to the state’s efforts to keep the mussels contained to Lake Powell, Utah’s other Utah reservoirs have tested negative for signs of the invasive species, the press release states.

If you choose to clean drain and dry your own boat, rather than having it professionally decontaminated, take the time to inspect its anchor and sea strainer, flush and inspect its cooling intake or water system and pull all bilge plugs. For all vessels with ballast tanks, inboard motors or other raw water systems such as the air conditioning unit and shower, the required dry time is always 30 days.


Email: [email protected]

Twitter: @MoriKessler

Copyright St. George News, LLC, 2018, all rights reserved.

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  • Not_So_Much August 23, 2018 at 8:30 am

    We really should spend 2 oh heck 3 billion on a pipeline. What could go wrong?

  • tazzman August 23, 2018 at 12:51 pm

    They need to start quarantining those boats and watercraft to just Powell and not allow any owners to bring any watercraft based at Powell anywhere else. There is too much at stake for all of the fish and aquatic life in all of the other water supplies.

  • youcandoit August 23, 2018 at 3:00 pm

    How about instead of raising our utility bills, fine the people who have boats. Why should everyone be punished for their negligence?

    • tazzman August 23, 2018 at 3:40 pm

      The people who put their boats and crafts on Powell should be tagged as having visited the lake and no other lake should be able to have the craft for that entire season.

  • comments August 23, 2018 at 7:19 pm

    Better hurry and build that pipe before the sheep start to wise up to what a bad idea it is…

    These oysters would like nothing better than a nice new pipe to infest. lol

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