Dreaded weed back in Lake Norman; Wylie OK for now

Hydrilla can clog boat engines and choke out coves. Boaters are asked to use care that it does not spread.
Hydrilla can clog boat engines and choke out coves. Boaters are asked to use care that it does not spread. Charlotte Observer file photo

A dreaded weed known as the “serial killer of eagles” has returned to a well-known part of Lake Norman, north of Charlotte. Downstream? It isn’t such a concern — yet.

“Right now, it is more contained,” Lake Wylie Marine Commissioner Dan Mullane said of hydrilla. “We are still doing the carp stocking annually at Lake Wylie. We have our situation under control.”

Still, reports of hydrilla on Lake Norman are a concern.

“Typically, we try to stay focused within the walls of Lake Wylie,” Mullane said. “But anything upriver obviously has the potential to come downriver. We do like to at least hear about these things.”

The nonnative hydrilla plant contains a bacterium with a toxin deadly to birds of prey, the Washington Post reported in 2015.

Across the South, near reservoirs full of the weed, eagles have been stricken by the bacteria, which go straight to their brains, according to the Post. Eagles prey on American coots, which dine almost exclusively on hydrilla, the Post reported.

Coots are black, medium-size water birds that spend time on Lake Norman but winter elsewhere, because the lake lacks the amount of aquatic vegetation needed to sustain them, former Observer Lake Norman fishing columnist Gus Gustafson reported in 2015.

Left unchecked, hydrilla also can choke out entire coves and clog boat engines.

Since the mid-2000s, the Lake Norman Marine Commission has treated outbreaks of the weed by adding thousands grass carp to the waters.

The carp eat up to three times their weight in aquatic grass daily and can grow to more than 50 pounds.

It is illegal to catch or kill them on the lake.

A new outbreak of the weed was detected in the Ramsey Creek area of Lake Norman late last year, and officials have been working with the N.C. Department of Environmental Quality to buy more of the carp, Ron Shoultz, the Lake Norman Marine Commission’s executive director, told the Mooresville Tribune this week.

Joe Kluttz of Duke Energy said the outbreak started at the Ramsey Creek Access Area off Nantz Road in Cornelius, N.C. signaling that the weed attached to someone’s boat elsewhere, and the boater brought it onto Lake Norman, the Tribune reported.

Hydrilla also has appeared around the intake valve at Blythe Landing , off N.C. 73 on the southern end of the lake, reported Dave Ferguson, a Mecklenburg County Water Quality official.

The Lake Wylie commission, Duke and wildlife agencies from both Carolinas partnered back in 2008 to stock 500 sterile Asian grass carp. Sterile fish are used to prevent them becoming yet another invasive species, but doing so means having to re-stock annually. In 2009 there were 1,800 fish poured into Wylie. Last spring there were more than 570.

Last year local, state and federal sources provided more than $2 million toward invasive plant control on South Carolina waters.

Mullane, who fishes both Wylie and Norman, said boaters can help Wylie keep relatively free of the weed. The weed can latch onto boat parts and trailers. Public boat landings throughout the area have signs asking boaters to clean their vessels.

“The message is still the same,” Mullane said, “that if you’re going to be taking your boat off the trailer and moving it to any other lake, we highly recommend that you are cleaning the under side of the boat, cleaning the wheel wells, really any part of the prop on the engine, and making sure that there isn’t any of these weeds on it.”

Joe Marusak: 704-358-5067, @jmarusak