The lakes and streams of the Ozarks teem with life in the silent underwater realm. Not every fish, not every aquatic plant, is a good thing for our waterways.
Zebra mussels, yellow bass, silver carp and the problem algae "didymo" are among the unwelcome invasive species in Arkansas' reservoirs and rivers. These invaders cause varying degrees of harm wherever they gain a foothold. Some have potential to harm boaters and anglers. What follows is an update on some of these invaders that biologists and water quality managers have an eye on.
Prevent The Spread
All water recreationists, from scuba divers to anglers to paddlers, can help prevent the spread of aquatic invasive species, including zebra mussels.
Inspect the boat’s hull, drive unit, any surface that gets wet including the trailer. Remove any weeds or suspected mussels before leaving any body of water.
Drain water from the motor, livewells, bilge and transom before leaving the body of water.
At home, thoroughly rinse with high pressure the hull, drive unit, livewells, bilge and other boat parts that get wet. A hard spray from a garden hose or a car wash is sufficient. Use hot water if possible.
Boats, motors and trailers should be allowed to dry thoroughly, ideally in the sun, for five days before boating on a different body of water.
Dispose of unused live bait on dry land. Clean waders after use and let dry. Use waders with hard soles, not felt soles.
Source: Arkansas Game & Fish Commission
Zebra Mussels
Knock on wood, Beaver Lake hasn't become infested with zebra mussels. Yet, they worry Jon Stein, Northwest Arkansas' fisheries biologist with the Arkansas Game & Fish Commission. Zebra mussels are found at Bull Shoals Lake and the Arkansas River. That's too close for comfort.
Though zebra mussels aren't in Beaver Lake, they're Stein's top invasive-species concern. The fingernail-sized mussels spread like mad, and attach themselves to outboard motors, buoys, water intakes, docks, the lake bottom, just about everything in the water, including other mussels.
They eat tremendous amounts of plankton, Stein said. That means less food for newly hatched fish that eat plankton until they become large enough to eat other food.
"Not only that, they're sharp. They'll slice you to shreds," Stein said. People swimming or wading can be hurt by zebra mussels.
If they find their way to Northwest Arkansas, they'll likely hitch a ride aboard a boat that has been on a waterway that has zebra mussels, then launched on Beaver Lake. Zebra mussels are transported in areas of a boat that get wet, such as a livewell or bilge. Their spread can be prevented by properly washing and drying a vessel, as outlined with this story.
"The thing about zebra mussels is the larvae are so small you can't see them with the naked eye," Stein said. That's why washing and drying are necessary before, say, pulling a boat out of Bull Shoals Lake and launching it at Beaver Lake. Visual inspection isn't enough.
Zebra mussels were discovered at Bull Shoals Lake in 2007, said Cody Wyatt, fisheries biologist with Game & Fish in north central Arkansas.
"On the upper end of the lake there are solid mats of zebra mussels from the shore down to 30 feet deep," Wyatt said. They haven't had a negative impact on fishing, he added.
The zebra mussel outbreak at Bull Shoals seems to have peaked, Wyatt said. "Hopefully it has bloomed out and it will decline, but it never goes away. There's almost nothing you can do. We have to learn to live with them, and keep them from spreading."
Miraculously, there are no zebra mussels in nearby Norfork Lake, next door to Bull Shoals. Biologists use their boats and other equipment at Bull Shoals and Norfork. That requires extensive washing and drying of equipment which increases the work load for the fisheries staff, Wyatt said.
Yellow Bass
Zebra mussels haven't found their way to Beaver Lake, but yellow bass have, said fisheries biologist Stein. These small fish, typically 4 to 6 inches, resemble white bass but are yellowish in color.
"A 12-inch yellow bass is a big one," Stein said.
The problem with yellow bass is they multiply rapidly and can overpopulate a lake. They eat shad and other bait fish which means less food for more desirable fish like black bass and crappie. Right now, yellow bass are present in small numbers at Beaver Lake and aren't a problem, Stein said.
"They may have been brought here by someone who netted some bait fish on the Arkansas River and dumped them into Beaver Lake," Stein said. Yellow bass may have been in with a batch of striped bass that were stocked in Beaver Lake, he said.
Yellow bass were discovered here in 2012 when a fisherman at Beaver Lake caught a couple and showed the fish to Stein.
"They occasionally crop up in our electrofishing studies, but not much," he said.
Largemouth Bass Virus
This malady isn't an invasive species, but is a virus that kills big largemouth bass. Largemouth bass virus was discovered at Beaver Lake 15 or 20 years ago, but is no longer a threat.
"It peaked ,and then dropped off. We haven't had any issues with it since about 2004," Stein said.
It's been a problem at other lakes.
"At Lake Monticello (Southeast Arkansas), 53 dead bass were found in a single day. All were 5 to 12 pounds," Stein said.
Creel surveys show it takes an average of 300 hours of fishing to catch a bass weighing 5 pounds, Stein said. In lakes with largemouth bass virus, that number nears 1,000 hours.
Didymo
This problem algae is found in the White River below Beaver Dam, said Christy Graham, state trout biologist with Game & Fish. It's present in the White River below Bull Shoals Dam and the North Fork River below Lake Norfork.
Didymo is a stringy algae that grows on the bottom of the White River and elsewhere. It can foul fishing lures and clog outboard motors. Didymo is short for a longer scientific name, and also has the nickname "rock snot."
"It's spread by waders, life jackets and other fishing gear," Graham said. "Anyone who sees clumps of algae on their waders should get rid of it." Let waders and other fishing gear dry for 48 hours before using the waders at another body of water.
It's more of a problem during low water flows, Graham said.
John Sturgis, president of the Arkansas chapter of Trout Unlimited, said didymo is heaviest below Beaver Dam during summer, but is present in winter.
"It floats, and you can see it distinctly on rocks below the surface on those gin clear water days," Sturgis said.
Felt-soled waders or wading boots with felt soles trap didymo and spread it around, he added. He would like to see Game & Fish ban felt-soled footwear on Arkansas waters, as other states have done.
Silver Carp
These carp can kill. Silver carp weighing 40 pounds or larger can leap from the water and strike occupants of a moving boat causing injury or worse. Vibrations produced by boat engines trigger silver carp to jump, often large numbers of them.
They can eat up to 20 percent of their body weight in food daily, and can be disruptive to aquatic food chains.
Silver carp are a species of Asian carp that are found in all of the Arkansas River within the state and the White River as far upstream as Batesville, said Mark Oliver, chief of fisheries at Game & Fish.
"We've not seen them above Lock and Dam No. 1 at Batesville. They only way they'll get any higher than that is in a flood or if they're introduced," Oliver said.
Netting baitfish at one waterway and using it at another is a common practice that can spread silver carp. People who net shad for bait might net some silver carp by mistake because the young carp look like shad. Anglers should never dump leftover live bait into the water, Oliver said. Always dispose of it on land.
Oliver said he was with some commercial fishermen Monday on the White River at Augusta. Silver carp were jumping all around, he said.
Game & Fish promotes commercial harvest of silver carp. That won't get rid of them, but it can reduce their numbers, Oliver said.
Mention White River and many anglers think trout. Oliver said it's unlikely, but not impossible, that silver carp could find their way to the White River below Bull Shoals or below Beaver Dam. These invasive carp could survive the constant cold temperatures of these tailwaters, Oliver said.
Outdoors on 12/17/2014