Dreaded weed known as ‘serial killer of eagles’ returns to part of Lake Norman

In this 2004 Charlotte Observer file photo, Asian grass carp are released into Lake Norman to munch on the invasive hydrilla weed.
In this 2004 Charlotte Observer file photo, Asian grass carp are released into Lake Norman to munch on the invasive hydrilla weed. Charlotte Observer file photo

A dreaded weed known as the “serial killer of eagles” has returned to a well-known part of Lake Norman.

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

Hydrilla can clog boat engines and choke out entire coves. Charlotte Observer file photo

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.

This sick and blind American coot was seen floating in hydrilla in 2012 at the J. Strom Thurmond Reservoir, bordering Georgia and South Carolina on the Savannah, Broad and Little rivers. Charlotte Observer file photo

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.

The Lake Norman Marine Commission passed an ordinance in 2004 making possession of the sterile Asian grass carp illegal. If you catch one, you should release it immediately. Charlotte Observer file photo

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 the lake 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 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, 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.

In response, the state has authorized stocking 10,200 grass carp in Ramsey Creek this spring, Duke Energy spokeswoman Kim Crawford said Thursday. The Lake Norman Marine Commission is leading the effort, in partnership with Duke Energy and Charlotte Water, according to Crawford.

Joe Marusak: 704-358-5067, @jmarusak