Quagga Mussel Infestation Greater Than Feared At Lake Powell In Glen Canyon NRA

Dropping water levels at Lake Powell in Glen Canyon National Recreation Area have revealed a much greater infestation of quagga mussels in the reservoir than previously thought.

In a release Tuesday, officials for the National Park Service said that since this time last year, the water levels at Lake Powell have dropped, exposing shorelines that were previously underwater, and revealing the non-native mussel infestation.

"Thousands of adult quagga mussels have been found in various locations, such as canyon walls, Glen Canyon Dam, boats, and other underwater structures," noted NRA spokeswoman Denise Shultz. "The majority of mussels found are isolated adults, with additional groupings of small clusters. One adult mussel was found on the south canyon wall of Bullfrog Bay."

Last summer, following an underwater inspection of the NRA's two major marinas on the lower end of Lake Powell, officials were optimistic the huge reservoir could still be kept free of a major infestation.

A total of 36 divers and 73 support staff participated in the project, which had two main goals: assess the extent of quagga mussels in lower Lake Powell, and remove all existing mussels. The outcome could be described as a classic case of both good news and bad.

On day one, June 10, divers found and removed 138 mussels at Antelope Point Marina. The second day yielded 63 mussels at Wahwep Marina, with an additional 22 of the creatures on June 12. On the final day, a dozen additional quagga were removed. The grand total for four days: 235 mussels.

According to a park spokesperson, divers located mussels on moored boats, docks, and breakwaters dispersed throughout both marinas, but did not find any large colonies of mussels. The mussels varied from the size of a pea to the size of a quarter, which suggests a range of different ages.

Following the latest news, NRA officials said boat inspections and decontamination of high risk boats are still required for incoming vessels at Glen Canyon. Continued mussel education and prevention activities, including boat inspections, are aimed at minimizing the chances that mussels will colonize other areas of the lake. It may also prevent the introduction of other aquatic invasive species.

It is crucial to keep the mussels from moving from Lake Powell to other lakes and rivers. When leaving Lake Powell, all watercraft are required by Utah and Arizona state law to be decontaminated (Clean, Drain, and Dry) before being moved to another water body. Regulations vary depending on the state, so all boaters should review the regulations of any states they will enter with their watercraft after being at Lake Powell, including Arizona and Utah.

To help stop the spread of mussels:

You must clean and drain your boat before you leave the vicinity of the lake.
You must dry your boat the required amount of time before moving it to another body of water.
OR you can have your boat professionally decontaminated.
“Park staff, partners, and the public have worked hard to keep Lake Powell mussel free for the last ten years,” said Superintendent Todd Brindle. “It’s very disappointing that mussels are in the lake, but most visitors will not notice them. The important thing now is to keep them from being transported to other lakes and rivers.”

A planning effort is currently underway to develop a Quagga/Zebra Mussel Management Plan (QZMP) to help the National Park Service decide what tools are appropriate to support the ongoing management of invasive mussels in Glen Canyon now that quagga mussels are present in Lake Powell. The QZMP will consider changes to the existing prevention and monitoring efforts, and will include analysis of potential control, containment, and other park management actions.


There's an article in this week's Science section of the NY [i]Times[/i] about a professor who discovered a bacterium that kills quagga & zebra mussels apparently without harming other creatures. http://www.nytimes.com/2014/02/25/science/science-takes-on-a-silent-invader.html
Yes, but Mike, there's that little word "apparently" in there. How many other times in our history as supposedly enlightened creatures have we introduced something that was believed to be "apparently" harmless only to discover later that we had really messed up? There are so many, many things about our world that we simply don't know or understand. How can we be certain this isn't one of those times?
Interesting article yesterday about a world record Redear Sunfish caught in Arizona in Lake Havasu. They say in the article that the quagga mussels may be why it grew so big. Different species being intoduced where they do not belong can have an interesting effect. See the picture of this pan fish here; http://outdoornewsdaily.com/pending-world-record-redear-sunfish/
[quote]How many other times in our history as supposedly enlightened creatures have we introduced something that was believed to be "apparently" harmless only to discover later that we had really messed up? [/quote] Of course the Quagga wasn't introduced with the belief it was apparently harmless. And yes, there have been cases where introductions have had unintended negative effects. Of course those cases are overwhelmed by the instances of new species being introduced with enormously beneficial results.
Reintroduction of a species that is critical or endangered is one thing but there are many introduced species that have had bad results.
[quote] but there are many introduced species that have had bad results.[/quote] No doubt. But how many of those were intended introductions? My guess would be that most you are referring to were unintended (by authorities) like the Quagga, the Yellowstone Lake Trout, Pythons in the everglades etc. The number of intentional introductions that went well would overwhelm the count of those that caused substantial harm.
"The number of intentional introductions that went well would overwhelm the count of those that caused substantial harm." If that were my assertion, this is where you would step in to ask for documentation. Please?
[quote]If that were my assertion, this is where you would step in to ask for documentation. [/quote] Tell you what Rick. For every bad intentional introduction you produce, I will produce four positive ones.
Yes, documentation, please.
Actually Rick (and Lee) I would like to rephrase since my positive introductions are so far more powerful. Its not the count the counts its the impact. Lets start with the introduction of cattle/cows. That has had an enormous positive impact on North America including feeding the nation, providing milk and a substantial contribution to the economy. Now, give me a intentional introduction that had anywhere near the magnitude from a negative sense.

"For every bad intentional introduction you produce, I will produce four positive ones."

Gracious, ec. Where to begin.

Here's a good start for some intentional introductions which have caused major economic damage:

1. Kudzu. "An estimated 2 million acres of forest land in the southern United States is covered with kudzu. Kudzu was promoted as a forage crop and an ornamental plant when it was introduced to the U.S. Kudzu"completely replaces existing vegetation. It has been spreading in the southern U.S. at the rate of 150,000 acres (61,000 ha) annually, "easily outpacing the use of herbicide spraying and mowing, as well increasing the costs of these controls by $6 million annually." Its introduction has produced devastating environmental consequences.This has earned it the nickname, "The vine that ate the South." sources: http://plants.ifas.ufl.edu/node/354  and https://dnr.state.il.us/Stewardship/cd/biocontrol/25Kudzu.html

2. Eichhornia crassipes, water hyacinth, "Water hyacinth is one of the world’s worst aquatic weeds. It infests rivers, dams, lakes and irrigation channels on every continent except Antarctica. It devastates aquatic environments and costs billions of dollars every year in control costs and economic losses." The plant is believed to have been introduced into the U.S. in 1884 at an exposition in New Orleans; within 70 years of reaching Florida, the plant covered 126,000 acres of waterways. This invasive nuisance is planta non grata in much of the world where it often jams rivers and lakes with uncounted thousands of tons of floating plant matter.http://www.dpi.nsw.gov.au/agriculture/pests-weeds/weeds/profiles/water-hyacinth

3. Salt cedar. It was brought over from Eurasia and planted in the US as an ornamental as well as for use as wind breaks, creating shade, and stabilize eroding stream banks. It escaped cultivation soon after, more than likely through natural means. Since you live in the West, you should understand this negative impacts of this plant along waterways. http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/T...

4. The Cane toad was introduced to the United States from South America in 1955. Originally, it was introduced to act as a pest control agent in sugar cane fields in Florida and Hawaii. Unfortunately, the cane toad has persisted in the environment, even though sugar cane production has declined in the United States. Cane toads are voracious predators of native species, and are highly toxic to predators. Each year, many household pets become sick after interacting with cane toads. http://democrats.naturalresources.house.gov/issue/invasive-species

5. European rabbits in Australia. "In 1859, Australia was given its worst Christmas present when 24 wild rabbits were released for hunting near Geelong. Economic damage by wild rabbits in Australia, including cost of control and production losses, has been estimated at around A$600 million annually." http://www.csiro.au/Outcomes/Safeguarding-Australia/European-Rabbits.aspx

No, I wont play this game indefinitely. It doesn't take long on a Google search to find more examples than any of us want to deal with.

Well jim, I would wager that there isn't an American that hasn't heard of beef or cows milk. The number that have heard of or been affected by Kudzu, water hyacinth, the salt cedar , the cane toad or European rabbits pales in comparison.

And back to the original subject of this story - and the first two comments that started this discussion.

I doubt that many would dispute the assertion that quagga and their relatives the zebra mussles have already caused enormous economic damage, and those costs are likely to grow. It's too bad efforts to keep them out of Lake Powell seem to have failed.

The possibility of a biological control for those pests is an intriguing idea, but as others have pointed out, such efforts have been known to backfire. As a result, this possible "solution" to the quagga problem needs to be approached with considerable caution.

An excellent book with many examples of unforeseen consequences is The once and future world : nature as it was, as it is, as it could be MacKinnon, J. B. (James Bernard), 1970- I highly recommend a careful reading to anyone who cares. And especially to those who don't care. Read it, ec, miracles do happen and you might actually see the light. ;-) ((Kurt, formatting options are still not working.))
Jim, Agree with you 100% on the Quagga. Just keep in mind, that was not a planned, authorized or intentional introduction. For Lee - I have MacKinnon's book on order from my local library system (shifting from another branch to mine). Meanwhile, I will enjoying my bread, rice, corn, lettuce, onions, cabbage, olives, grapes, lamb, and honey - just a few products from a long list of non- native species.
ec, you really, really, really need to check your list of "non-native species." At least three are wrong.
[quote]At least three are wrong.[/quote] Please do tell.
Lee, in response to your comment at the top of the thread (nesting replies don't seem to be working): I was only reporting that the article came out, nothing more! I am well aware of the potential problems of introducing species of all sorts into ecosystems.
Mike, I was trying to point that out for others who have shown us that they need to learn. ec, a good teacher tells a student to find the answers on their own. They learn much more that way. How about you tell us which ones you got wrong? That would make ol' Socrates proud of you.
Lee, I not looking for Socrates' approval. I am looking for edification. My sources indicate those listed are correct. If you think otherwise, please let us know and I will investigate further.
Better investigate further and check your sources.