Carp are back and thriving in Carter Lake.
"There appears to be two year classes (2011 and 2012)," said Chris Larson, the southwest regional fisheries supervisor, for the Iowa Department of Natural Resources.
A recent electrofishing survey by fisheries staff of the Nebraska Game and Parks Commission "captured less largemouth bass and more carp than in 2011," Larson said.
Carter Lake had been treated in October 2010 to remove the unwanted carp and to help improve the water quality of the lake.
"I am confident we did a good job with our chemical application in the fall of 2010," Larson said. "I believe someone stocked them on purpose to reverse the water quality improvement efforts that we completed. There were some that were very upset with the rooted aquatic vegetation that followed the improved water quality. I have no proof, but there were threats to stock carp from a few of the residents around the lake."
During the Game Commission survey, there were 15 carp captured, said Mark Porath, a fisheries biologist with the Nebraska agency. The larger carp were "of a length usually found in older fish, we can easily surmise that they didn’t survive the fish renovation, but gained access to the lake afterwards."
The water quality of the lake may have already started to decline because of the presence of the carp, which "root out" aquatic vegetation and stir up sediments.
"From what I hear it may have already started," Larson said. "Water clarity is not as good this spring compared to 2012, but it may also be because of the colder water temperatures. My hope is we can get along for a few more years. Typically 5-10 years is about all we could hope for before the water quality deteriorates to the point of being unacceptable."
Additional fish surveys are planned, especially this autumn, and will provide further information on the condition of the lake fishery.
Carp spawning at Levi Carter Pond, May 15, 2013. Photo by James E. Ducey.