Invasive species: Cause for concern?


Like water readily flows down and out to the lowest spots, wild flora and fauna spread with relative ease when they are given access to new habitat.

Plants and animals that come from afar to sprout or spawn in a location where they previously did not live are known as invasive species. Round gobies and zebra mussels are two good examples of recent invaders.

When the invasions become known, people become alarmed. Anglers pushed the panic button recently when a monster fish was discovered in the intake of the W.D. Sammis power plant on the Ohio River a few miles below Wellsville.

People who love to fish the big river were shocked. Many worried it was the first tick of the Ohio River Doomsday countdown.

The size of the fish, perhaps 50 or 60 pounds, and the fear it was one of the jumping carp species helped fan the flames. The invasion, anglers concluded, had reached our shores.

Fortunately, the oversized fish was not the silver carp. Silvers are the fish featured in a number of YouTube videos leaping in front of speeding boats.

Rich Carter, executive administrator of Ohio Department of Natural Resources’ Fish Management and Research, confirmed the Sammis carp was a bighead. While it’s apparent at least one individual has reached the Upper Ohio, Carter said the extent of the spread is not fully understood.

Carter said Ohio is partnering with Kentucky, West Virginia, Indiana, Illinois and Pennsylvania to gain more understanding about the invaders’ movement and behavior.

“At this point, the biggest concentration on the Ohio River is near Louisville,” Carter said. “We know that bighead have been in the Ohio Valley for at least 25 years, based on early discoveries near Marietta and the Muskingum River.”

Silvers jump when agitated by boat engine noise. Bighead are not known as jumpers.

“Both are filter feeders, with long gillrakers to strain zooplankton, which is the same food young gamefish eat before switching to minnows and shad,” Carter said. “The more these fish become established, the more they have the capability to outcompete native species.”

The arrival of grass carp in Lake Erie is another invasion threat. Carter said grass carp eat aquatic vegetation and thus impact feeding and nursery habitat for fish and waterfowl.

Anglers who catch one of the invasive carp species should report the catch. Local anglers can call the Division of Wildlife office in Akron at 330-644-2293. Carter also recommended that anglers not release invasive carp to the water alive.

Whether the Sammis plant bighead is a sign the species will become established in the Upper Ohio remains to be seen. Carter said two possible impediments exist.

One is the fact bighead eggs float as the embryos develop, and they need between 60 and 90 miles of free-flowing water to hatch. The other is the fact that young bighead need lots of backwater habitat, which is in relatively short supply in the Upper Ohio Valley.

While all conscientious anglers and scientists are concerned when invasive species take hold, it doesn’t necessarily mean the fishing for native species is doomed.

Many recall the great concern that surrounded the discovery of gobies in Lake Erie. Gobies’ great appetite for smallmouth bass eggs convinced many anglers that Erie’s smallies would soon be wiped out.

Turns out, however, that smallmouth found out how to get even.

“Lake Erie smallies’ diet today is 79 percent gobies,” Carter said.

jack@innismaggiore.com

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