FOR IMMEDIATE RELEASE
January 30, 2012
Media Contact: Brian Van Zee, (254) 867-7974, brian.vanzee@tpwd.state.tx.us
Zebra Mussel Test Results on North Texas Lakes Reported
Boaters urged to continue to Clean, Drain and Dry boats moved between lakes
ATHENS—Despite recent test results showing zebra mussel DNA to be present in several North Texas reservoirs, Texas Parks and Wildlife Department (TPWD) and U.S. Fish and Wildlife Service (USFWS) officials remain hopeful that the invasive aquatic species is still confined to Lake Texoma.
Dr. Robert McMahon, Professor Emeritus of Biology at the University of Texas at Arlington, has been monitoring 14 North Texas reservoirs for the presence of zebra mussels using three techniques. One technique looks for zebra mussel DNA in the water, another uses a microscope to look for zebra mussel larvae (veligers) in the water, and the third uses a submerged monitor to look for newly settled juvenile mussels.
Lakes involved in the study include Eagle Mountain, Lewisville, Lavon, Ray Hubbard, Ray Roberts, Arrowhead, Bridgeport, Tawakoni, Caddo, Wright Patman, Fork, Lake O’ the Pines, Caddo and Texoma.
Of those lakes, only Lake Texoma is known to be infested with zebra mussels.
Despite rigorous and repeated sampling in North Texas, Dr. McMahon has detected no zebra mussels of any life stage in any Texas lake other than Lake Texoma. Nevertheless, the most recent tests, carried out in October 2011, showed low levels of zebra mussel DNA in six lakes: Eagle Mountain, Lewisville, Ray Roberts, Arrowhead, Bridgeport and Caddo.
“Lakes Lavon, Ray Hubbard, Tawakoni and Wright Patman had no detected zebra mussel DNA in the samples,” said McMahon. “Lavon and Ray Hubbard tested positive for zebra mussel DNA in the spring of 2011, so the absence of any veliger DNA in the fall samples suggests that mussels have not become established in those lakes. Lakes Fork, Lake O’ the Pines and Bob Sandlin were not examined for mussel DNA in the fall of 2011, because they were considered inhospitable to zebra mussels based on high summer temperatures and low calcium levels.”
The presence of zebra mussel DNA in the water is not an indication that zebra mussels have become established in a lake or that they will become established. “There are cases in the western U.S. where positive DNA results indicated the presence of zebra mussels, but those results could never be confirmed,” said Brian Van Zee, TPWD Inland Fisheries regional director. “In fact, Lakes Ray Hubbard and Lavon tested positive in the spring of 2011 for zebra mussel DNA, but the presence of zebra mussels could not be confirmed by microscopy or settlement samplers. The spring 2011 samples were taken right around the time that contaminated boats were found on both lakes, so that may be why they tested positive. Both boats were removed and decontaminated, and subsequent monitoring on these two lakes, by three different entities, has not confirmed the presence of zebra mussels.”
McMahon noted that he was surprised by the positive result for Caddo Lake. “I consider the lake’s calcium levels to be too low and the summer water temperatures too high to support zebra mussels,” he said.
Microscopic examination of water samples from the 14 lakes in both June and October 2011 showed zebra mussel veligers present only in Lake Texoma. “During June juvenile mussels were found on settlement monitors only in Lake Texoma, while no juvenile zebra mussels were found on settlement monitors in any of the 14 lakes in October, including Texoma,” McMahon added.
McMahon suspects that boats being transported from Lake Texoma to other lakes are the source of the DNA found in the six lakes. “The data suggest that mussels and/or mussel larvae are being carried into these lakes by recreational boaters but are not becoming established as a sustainably reproducing mussel population,” he said. “This is a sign that mussels are being introduced to Texas lakes, and if such introductions continue, some of these lakes may eventually become infested with zebra mussels.”
“TPWD will continue monitoring these lakes for the presence of zebra mussels and doing everything it can to encourage boaters and anglers to Clean, Drain and Dry their boats for at least a week before moving them to another lake,” Van Zee said. “We encourage boaters and anglers to visit http://www.texasinvasives.org/ to learn more about how they can help protect the waters they enjoy.”
Concern over the possible transport of zebra mussels between bodies of water prompted TPWD to propose new regulations governing movement of boats or fish between lakes in North Texas. Details on the proposed regulations can be found at http://www.tpwd.state.tx.us/newsmedia/releases/?req=20120126b.

Has any study been done involving mirgratory birds that travel from water body to water body in one day. If these veligers can live on a boat hull or trailer for several days it would only make sense they could live for a couple of hours of flight from one water body to the next.

Agree Tim... That is how many stock tanks end up with fish that have never been stocked. Birds carry larvae/eggs in the webbs of their feet and land in another body of water.

Is there any reason why PK is not included on that list? It seems that it would fall into the same habitable range as Texoma. Also, do these thing survive in river systems? It would seem that a hot summer would raise the temps enough in a river to kill them off.

Can see Texas lakes doing what the lakes in New Mexico doing. Every tournament your boat has to be inspected and sticker put on, if on lake without sticker you asked to leave lake. This rule for tournament boats only, they open check point at 6:00am and you wait in line. If you can get there on Friday in time can get done then.

I am a new memeber an could anyone tell me how you can upload photos? I read how bt i cant get it to work. So if anyone can help it wuld be great

I can see where this should be a major concern for guides also. Many of them do trips on mutiple lakes much like tournament participants.

Host your photo on a site like photobucket. Use the [img]your photo[/img] format.

Ok thank

+1! Id imagine this could slow the spread but then it'll make people mad too.

I'd rather have angry people than infested lakes.

Zebra mussels are from the Caspian Sea region (in Asia north of Afghanistan, Turkmenistan, and Iran), and they came to North America on ships. Zebra mussels stick themselves to objects (like the ships) and are moved around mainly by ships. They are very small, almost the size of your fingernail (50 mm). They are like a smaller mussel that you would see in an ocean, but zebra mussels are mostly found in fresh water.

Are there any updates as to IF and WHEN the requirement for boats to drain their livewells will be enforced on Lake Texoma?

Very true...people never want to see the bigger picture if it in anyway inconveniences them.

Draina livewell all you want...there will always be leftover water. You can't get them completely dry unless you wipe em down with a towel and bleach the inner surface...and even then...there is still water in the hoses that run the bilges, aerators, etc. That was a good point Mr. Cline about birds migrating. I have seen these mussels firsthand in Texoma...and Eufaula, Robert S. Kerr resevoirs in Oklahoma. We can do all we cando to limit their spread, but it is just a matter of time until they are in every Texas resevoir.

Great point about guides at Texoma guiding in other waters. I have used a Texoma guide before who also guides on Cedar creek, in different trips in the less than 10 day time period. And if I was a betting man, which I have been known to be...what about the people who never fish Texoma except for once a year at family reunions/vacations/striper expeditions in the metroplex who fish a lot here? Wonder what Joe Pool and Lake Arlington would say with the DNA tests on zebra mussels.

All are good points to be considered...

If they find a zebra on your boat or in your boat now you will get ticketed for transporting invasive species after September first the new regulations saying you must remove all water from livewells and bilge areas before leaving the lake will go into affect unless something changes and there is a chance it will happen sooner if the law is giving special consideration.

All the regs that may come into play for boats leaving Texoma...... how many gallons of water goes through the generating turbines every time they open the gates on the dam? How many feeder creeks come off of the river system that are supplied from Texoma water? What if Texoma fills up to 640 again and water goes over the spillway?

Putting regs on boaters is only a small item to the bigger picture and I don't think will have any positive effect on the spread of Zebra's. The Zebra's will eventually make their way into all lakes. It's not if, but when and only time will tell.

This is true

No doubt it will eventually spread throughout the state. But, one thing I do to slow it down is when I get home I put the hose in my livewells and circulate the water through the pipes and hoses. Chemicals in the tap water will kill any zebras.

I wonder how this will play out for the BLT championships. Perhaps an exemption so we can haul the fish to Gander Mountain would be in order.

I have made the BLT trail aware over a month ago so they can work with Bruce Hysmith up here to either keep the weigh-in at Gander or move it to the lake somewhere. Worst case is they have to switch lakes. I do not know if they have followed up with the State or not.

I hope they can still have it on Texoma. It's a heck of a fishery in the Fall.

I've seen mussels in Lake Worth. I don't know if they are the Zebra species or not.

Zebra mussels are the only species of freshwater mussel likely to be encountered that is attached to a substrate (stuck onto something, not buried in the mud). They are small, no bigger than a dime and striped, like a zebra.

Cleaning and sterilizing your live well is always a very good idea. It was through bass fishing out of boats with livewells that spread the Largemouth Bass Herbes Virus from the East to West coasts many years ago.

They get bigger than a dime and grow up to quater size when they are fully grown. Do not discount some that are larger than dimes as not being a zebra. Up here on Texoma there are a ton that are as big as quarters.