FOR RELEASE SUNDAY, AUGUST 4, 2013, AT 12:01 A.M. EDT - In this June 4, 2013 photo, John Jessup, left, spreads the Aquatic Herbicide pellets near the docks on Lake Waccamaw, N.C. as Cole Hulon, drives the boat. They are with PLM Lake & Land Management Corp. managing the growth of Hydrilla , an invasive water plant that can be harmful to fish. It also creates a mat on the surface of the water that makes swimming or boating impossible. It's a growing problem across North Carolina. (AP Photo/The Fayetteville Observer, Cindy Burnham) MANDATORY CREDIT
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FOR RELEASE SUNDAY, AUGUST 4, 2013, AT 12:01 A.M. EDT - In this June 4, 2013 photo, John Jessup, left, spreads the Aquatic Herbicide pellets near the docks on Lake Waccamaw, N.C. as Cole Hulon, drives the boat. They are with PLM Lake & Land Management Corp. managing the growth of Hydrilla , an invasive water plant that can be harmful to fish. It also creates a mat on the surface of the water that makes swimming or boating impossible. It's a growing problem across North Carolina. (AP Photo/The Fayetteville Observer, Cindy Burnham) MANDATORY CREDIT

Fast-spreading weed invades Lake Waccamaw

The Associated Press

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LAKE WACCAMAW, N.C. (AP) — Nobody knew what it was at first, just an incredibly fast-spreading aquatic weed near the public boat ramp on Lake Waccamaw.

Rob Emens, an invasive species specialist with the state Division of Water Resources, had no such doubts.

Emens visited the boat ramp in October and immediately knew that the plant fragments he saw floating in the water could be only one thing: the dreaded hydrilla.

The weed is so invasive that it threatened to choke almost all of the nearly 9,000-acre Lake Waccamaw in as little as five years if left unchecked.

Armed with that knowledge, the state moved just as fast. In early June, it began treating affected areas of the lake - about 600 acres - with a herbicide called fluridone. The state will share the $196,000 cost with the town of Lake Waccamaw and Columbus County.

And that is only the beginning.

The lake will need another treatment next month after more surveys are done and probably a third treatment later this year. Emens estimates that the cost will spiral to a total of nearly $500,000 this year and to $4 million within eight years.

He said state officials hope to have hydrilla in check within six years, but there certainly is no guarantee.

Hydrilla was discovered in Lake Gaston, near the Virginia state line, in the 1980s. The plant remains, despite spending as much as $1 million a year in eradication efforts.

Lake Waccamaw, about 12 miles east of Whiteville, is the largest of the Carolina bay lakes and the third-largest of the state's freshwater lakes. It is home to nearly 50 species of fish and mollusks, many of them considered rare and threatened. One species of endangered fish - the silverside - is found nowhere else in the world.

Left untreated, Emens said, hydrilla would have threatened Lake Waccamaw's entire ecosystem. Fishing, boating and swimming would have become all but impossible. Property values would have dwindled.

So how, then, could the state let this aquatic kudzu get into such a treasured body of water?

It had little choice.

Hydrilla typically spreads from lake to lake by hitchhiking on boat propellers. Left to dry out, it quickly dies, Emens said. But a clump of hydrilla kept damp on a propeller or in a live well can survive for days, even weeks. Once the plant takes root in a lake bed, the nightmare begins.

Hydrilla can reproduce by sprouting plants from stem fragments. But the main nemesis are tubers that settle in the lake bed. Think of a potato sprouting new shoots with remarkable quickness. Or remarkable slowness. Emens said the tubers can lie dormant for years, the main reason eradication is so difficult.

Hydrilla can grow from the lake bed to a height of about 18 feet, making the shallow Lake Waccamaw - its deepest point is only about 11 feet - an ideal host. Once it reaches the surface, hydrilla spreads into a dense, almost impenetrable mat of leaves and stems.

State and local officials debated on the best way to get rid of hydrilla in Lake Waccamaw. Grass carp, a big Asian fish that feasts on aquatic plants, is one method of controlling the noxious weed. Although considerably cheaper than herbicide treatment, the carp feast on all varieties of a lake's plants, which can cause an imbalance in the ecosystem if the carp are overstocked.

In the end, fluridone was chosen because it mainly attacks just the hydrilla and does not harm fish or people.

Regardless of the eradication method chosen, the problem is not going away anytime soon.

"Hydrilla is just a huge black cloud over that (lake) right now," Emens said.

And although improvements in hydrilla management are being made, nothing is on the horizon "that would radically improve the process," said Rob Richardson, an associate professor and extension specialist with N.C. State University.

Like kudzu, hydrilla was introduced in the United States from Asia for its esthetic value - kudzu for gardens, hydrilla for use in aquariums.

One took over the land, the other, the water.

Hydrilla is believed to have been introduced in the wild in Florida in the 1960s. Someone is thought to have dumped out an aquarium containing hydrilla, which escaped into a canal system and then spread into nearby ponds, Emens said. Now, hydrilla can be found in almost every major water basin in Florida, which spends more than $10 million a year in control efforts.

Emens said North Carolina has a different strain of hydrilla, one that can survive colder winters and was introduced here by unknown means in the late 1970s.

It was discovered in Wake County's Umstead Park in 1980. A year later, a survey found it in 11 locations, mostly in Wake County. By 1990, hydrilla was found in 51 locations. Today, hydrilla can be found in almost every North Carolina county, Richardson said.

Despite eradication efforts, Emens said, a lake in Umstead Park still has hydrilla.

If all of this sounds like something out of a horror movie, well, it only gets scarier.

Researchers in South Carolina have found that hydrilla has become a perfect host for blue-green algae, a toxin that causes the disease avian vacular myelinopathy, which attacks the nervous systems of bald eagles and waterfowl.

Emens said waterfowl feed on the algae and become disoriented, causing them to fly erratically and making them easy prey for predatory birds, such as the bald eagle, which also becomes infected and dies. Researchers in South Carolina link the deaths of more than 100 bald eagles to the disease.

In North Carolina, hydrilla continues its rapid march. Although it thrives best in shallow lakes and farm ponds, it is beginning to show up in some of the state's rivers and in the Albemarle Sound.

Within the past 10 years, Emens said, hydrilla has taken root in the Eno, Neuse and Chowan rivers, causing additional problems because the weed is much harder, if not impossible, to manage in rivers and sounds.

If that's not bad enough, the state's lakes and ponds are becoming even more threatened because hydrilla is getting closer to them. Hydrilla is not only transported by boats but also by wildlife.

"The distance it has to travel over land is shortening, so, statistically, that would lead to more events," he said.

Nobody knows for sure how hydrilla got into Lake Waccamaw. But one possibility is that it came from a lake at the Indian Cultural Center near Pembroke, about 50 miles away.

Emens said hydrilla was identified in the Indian Cultural Center's lake about five years ago. Since then, the lake has been treated with herbicide and grass carp. Although the lake is in much better condition today, Emens said, it still contains hydrilla.

He said he has been told that a fisherman often fishes in both the Indian Cultural Center lake and Lake Waccamaw.

Not everyone hates hydrilla. J.T. Palmore, a professional bass angler until last year, said the best fishing lakes in the country contain the invasive weed.

Palmore was born on Lake Gaston, and he does not understand what all of the fuss is about. He worries that killing the hydrilla with herbicides reduces the lake's dissolved oxygen content and hurts the fish population.

"I wouldn't spray it at all, but I don't have a million-dollar home there," he said. "The best thing to do is find a natural balance."

There is at least one piece of encouraging news in eradication efforts. Emens said a six-year campaign to kill hydrilla in the Tar River Reservoir in Rocky Mount has been effective using a combination of herbicide and carp.

Emens estimates that the number of hydrilla tubers has been reduced in the reservoir by 99.5 percent or better, but some remain dormant.

"They are still out there," he said.

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Information from: The Fayetteville Observer, http://www.fayobserver.com

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