There are numerous varieties of aquatic nuisance species — from plants, to mollusks, to fish and crustaceans.
Harman can tell you off the top of his head which ones have taken up residence in Otsego Lake, which ones have been there but have been eradicated and which ones have still not found there way there, as well as which native species were once there but have vanished for one reason or another.
Water chestnuts have been found in Otsego Lake, although there has been some success in keeping them in check. Zebra mussels are not in the lake, and Harman is hoping those participating in Sunday’s outing will keep an eye out of them.
One non-native species of fish that has caused problems for the lake’s ecosystem is the alewife, first documented in Otsego Lake in the 1980s. While the lake trout fattened up on the alewife, they were getting out of control and eating more than their share of the lake’s zooplankton. That resulted in a bloom in algae and lake water that was cloudier and greenish.
Then the researchers at the Biological Field Station concluded that they could knock back the alewife by stocking the lake with walleye. Since the walleye stocking began in 2000, the alewife population has been sharply reduced and the lake water has been clearer, Harman said.
“It’s really helped the situation nicely,” Harman said, noting the National Science Foundation has taken note of Otsego Lake’s success with the walleye stocking program.
The lake has some Eurasian milfoil but that species of aquatic plant is being contained by four types of insects that feed on it, Harman noted.
“We have been doing a nice job with early detection and rapid response,” he said.”The targets now are the things we know that aren’t here yet, but we still need to be aware of them.”