Kristy Meyer, October 28, 2013
State wildlife officials have confirmed the find of four grass carp that were a result of natural reproduction in the Sandusky River.
In 2012, commercial anglers reported collecting 10 grass carp from Lake Erie and the Sandusky River. Of eight fish that could be tested, five were confirmed as diploid grass carp – carp capable of reproducing and four of which were a result of natural reproduction.
In 2012, the United States Geological Survey confirmed everyone’s worst fears that Asian carp, like bighead and silver carp, could establish themselves in the Maumee, Sandusky, and Grand Rivers.
This recent finding of one-year-old grass carp supports that recent research, suggesting that other, more destructive, species of Asian carp could also establish themselves in these river systems.
In an effort to try and stay ahead of an invasion, earlier this year the Ohio Department of Natural Resources collected additional samples from the Ohio Lake Erie watershed and key areas in the Ohio River watershed.
Of the eight grass carp collected across the state, only one fish came back as a diploid. This fish was caught in the Maumee River.
“This goes to show that the outreach and education that the Ohio Division of Wildlife has been doing is paying off,” said Kristy Meyer, managing director of agricultural, health & clean water programs at the Ohio Environmental Council.
“Anglers could have been catching grass carp for years and throwing them back, not knowing whether or not they were diploid carp and not fully understanding the potential devastating impacts they can cause to native habitat and therefore wildlife. But now, more anglers are turning suspect fish over to state game officials.”
Since 1988, Ohio has been stocking and allowing others to stock triploid – “sterile”- fish in ponds and lakes throughout Ohio to control aquatic vegetation.
Grass carp were first imported into the United States in 1963 for vegetation control in Stuttgart, Arkansas. Many of these early stockings were in lakes or reservoirs open to stream systems.
Shortly after their importation to Arkansas, the fish escaped the Fish Farming Experimental Station in Stuttgart, Arkansas. Within ten years of their introduction, feral populations of grass carp became established in the White and Mississippi Rivers, prompting interest in the use of triploid fish.
Grass carp feed on aquatic vegetation. They favor densely vegetated inshore areas of backwaters within large rivers, ponds, and lakes three to ten feet deep, but prefer large, slow-flowing or standing water bodies. Old Woman Creek in the western Lake Erie basin is rich with macrophytes like coontail and sago pondweed, upon which grass carp feast.
If enough grass carp got established in such a waterway, they could significantly alter the ecosystem, potentially wiping out important native plants that serve as food and shelter for other aquatic life. That is a huge risk to prized sport fish and rare and endangered fish species.
“Grass carp breed like mosquitoes and eat like hogs,” said Meyer. “It does not take many of these fish to reproduce, nor does it take many to completely change the make-up of the plant community, potentially altering the food web.”The OEC thanks the Ohio Division of Wildlife for quickly assessing the situation and putting together a tactical plan that not only addresses stopping the spread of these fish, but also working to keep the more destructive bighead and silver carp out of the Great Lakes,” said Meyer. “We look forward to working with Wildlife officials and other partners to protect our waterways from Asian carp.”