- Associated Press - Monday, June 30, 2014

BISMARCK, N.D. (AP) - North Dakota appears to be holding its own when it comes to curbing the spread of aquatic nuisance species compared to other states.

Last year, the Game and Fish Department checked about half of the state’s 400-some lakes and found just one new infestation - curly leaf pondweed in Grass Lake in Richland County.

In 2013, the North Dakota Game and Fish Department issued 35 ANS violations. That’s up from about a dozen from the previous year.

The list of aquatic nuisance species found in the state so far isn’t very extensive, with only 15 lakes listed as having infestations.

The two primary plant species of concern are Eurasian watermilfoil and curly leaf pondweed.

With the new infestation at Grass Lake, curly leaf pondweed has now been confirmed in 12 state waters: Lake Ashtabula, Barnes County; Lake Audubon, McLean County; Lake Elsie, Richland County; McClusky Canal, McLean County; McDowell Dam, Burleigh County; Lake Metigoshe, Bottineau County; Missouri River, Burleigh, Emmons, McLean, Mercer, Morton and Oliver counties; Lake Oahe, Emmons and Morton counties; Riverdale Spillway Lake, McLean County; Lake Sakakawea, Dunn, McKenzie, McLean, Mercer, Mountrail, and Williams counties; and the Sheyenne River in Barnes County.

Fred Ryckman, the ANS coordinator for the Game and Fish Department, told The Bismarck Tribune (http://bit.ly/1lO6fE1 ) that the aquatic vegetation species are a problem because over time, they can overtake a body of water, choking out native plant species that provide diversity for various species that comprise the food chain.

The state’s other vegetative infestation is Eurasian watermilfoil, which has been found in Dead Colt Creek in Ransom County and in the Sheyenne River in Barnes County.

Ryckman said for the most part, once invasive aquatic species are here, they are nearly impossible to eradicate.

“Unfortunately, the general consensus is there is not much you can do once they’ve been established,” he said.

Greg Power, fisheries chief, said generally, infestations are stable or appear to be in decline and there have been some successes battling the spread of Eurasian watermilfoil.

In Dead Colt Creek, water levels were drawn down three consecutive winters in hopes the watermilfoil would freeze out over the winters.

“Apparently it was successful,” Ryckman said. “We have not been able to find that plant the last couple of years.”

He said the two animals that are of the most concern are zebra mussels and silver carp.

Silver carp were found in the James River following extremely high water in 2011 and a few adults were still showing up in nettings last year.

Ryckman said the number of silver carp isn’t huge and they are likely start to lay eggs in the next few years, but it’s unknown if the James River will prove to be suitable habitat for them to do well.

And as far as zebra mussels, after an initial discovery of immature mussels in the Red River in 2010, they haven’t been detected the past two years.

Ryckman said Minnesota already has a well-documented presence in the Ottertail River, which flows into the Red River at Wahpeton.

Zebra mussels not only create problems by clogging intake structures like those found at municipal water plants, irrigation pumps and power plants, but they also feed on plankton.

Ryckman said they are prolific reproducers and can disrupt the balance of the food chain by removing plankton that in-vertebrate rely on, which in turn, affects the food base for minnows and other forage that fish use.

Last fall, however, adult zebra mussels were discovered in Lake Winnipeg in Canada, meaning they are now upstream and downstream from North Dakota.

Power said only time will tell whether zebra mussels will get a toe hold in the Red River.

The newest exotic species threat might be the rusty crayfish, he said. Rusty crayfish have been found in much of Minnesota, Wisconsin, Michigan, Illinois, Ontario, and portions of 17 other states. It’s thought they are able to out-compete native crayfish, which are a forage base for many fish species.

And as is the case with exotic plant species, they ultimately decrease the number and the variety of aquatic plants and animals.

Wildlife officials believe that rusty crayfish were introduced into Minnesota and elsewhere by anglers using the exotics as bait.

Because many North Dakota waters are destinations for out-of-state anglers, the Game and Fish Department said it has shifted a good deal of its re-sources to monitoring for ANS, particularly in the eastern part of the state.

Checkpoints will become more common as game warden patrols checking boats and equipment for potential exotics will become standard operating procedure.

Several years ago, the state approved new regulations aimed at stopping the spread of ANS.

The regulations require boats to be drained of water from the live wells, bait wells, bilges at the ramp before leaving a body of water.

Anglers can still use their live wells to transport fish home by adding ice, as long as the water has been drained at the ramp.

It’s also required that boats, trailers and all gear be cleared of any vegetation at the ramp to prevent the transfer of plant material to other bodies of water.

There also are regulations specific to how bait is handled and transferred after a day on the water.

Only 5-gallon or smaller containers are allowed to be used to transport bait.

Ryckman said it’s probably impossible to stop the spread of ANS into the state, but the alternative is not an attractive proposition.

When exotics become established, they are likely here to stay.

“Typically what you have, you have to live with,” he said.

___

Information from: Bismarck Tribune, http://www.bismarcktribune.com

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