08-17-08: Tens of thousands of fish die at state park

(c) 2008 The Virginian Pilot

By Hattie Brown Garrow, Staff Writer

Tens of thousands of fish have died suddenly in a 760-acre pond in a North Carolina state park, and parks and recreation officials are blaming an invasive aquatic plant species.

Decaying parrot feather likely has depleted oxygen levels in the pond at Merchants Millpond State Park, suffocating about 125,000 bass, bluegill and catfish, park superintendent Jay Greenwood said.

The pond is closed until further notice, even as the Gates County park's busy fall season approaches, Greenwood said.

The pond has been popular among anglers and as a paddling spot for canoe and kayak enthusiasts. Campers flock to the site every year to pitch tents on the two roughly 10-acre "islands."

The 3,296-acre state park averages 200,000 visitors a year, Greenwood said.

"The millpond is definitely our centerpiece," he said. "People come here from all over the world for our millpond."

Park rangers first noticed masses of fish floating on the pond's surface on Tuesday, Greenwood said. They contacted the North Carolina Wildlife Resources Commission and North Carolina Division of Water Quality, who confirmed that parrot feather was the likely cause.

This is the first time park rangers have seen a huge bloom of parrot feather in the pond, Greenwood said. Knowing the problems it could cause, rangers had planned to remove the plants by hand before they were expected to die later in the year, he said.

Parrot feather is native to South America but has spread to bodies of water in the United States, said Charlie Peek, a spokesman for the North Carolina Division of Parks and Recreation. It's "nasty stuff" that was introduced into the country because of its popularity in aquatic gardens.

"In smaller doses, it's more or less attractive," Peek said. "Once it gets in the wild, it just swallows up everything.... It upsets oxygen balance."

In this instance, it was a combination of the parrot feather's density and its death that caused the fish kill, district fisheries biologist Kevin Dockendorf said. The parrot feather had formed "dense mats of vegetation" that consumed the pond's oxygen as it decayed.

The fish could have been wiped out by a native plant under the same circumstances, said Dockendorf, who works for the North Carolina Wildlife Resources Commission.

"It's a bad thing. Then again, it's a natural thing," he said.

Twin aerators are to be installed in the pond in the coming weeks. The aerators will promote decomposition of the dead fish - which will not be removed - and restore oxygen levels for the remaining fish.

"We feel there's a considerable population of survivors," Peek said.

This isn't the first time the state park's pond - built in 1811 for a mill operation - has faced a large fish kill. Just after Hurricane Isabel in 2003, damaged trees stirred up oxygen-depleted soil, killing a good portion of the fish population.

Rangers and state wildlife officials made improvements to the pond and restocked it, with no problems until now, Greenwood said.