The Iowa Department of Natural Resources says an annual fish survey of East Okoboji Lake found bighead carp present. D.N.R. invasive species specialist, Kim Bogenschutz, says bighead carp are a river fish and dams normally stop them from moving — but they believe wet conditions allowed them to get into the lake.
She says the flooding on the Missouri River in turn flooded the Little Sioux River, which then flooded Milford Creek and that triggered the bighead carp to move into the lake. The bighead carp are part of the Asian carp group that are not native to Iowa and they can take over rivers.
“Like all invasive species they grow fast, they reproduce quickly and they form really large populations given the right conditions,” Bogenschutz says, “there are places in the Missouri River and parts of the Illinois River where they have been a long time where most of the fish you catch there are bighead carp, the other fish have been pushed out.”
The good news for East Okoboji Lake is that the bighead haven’t shown that they can thrive in lake conditions. Bogenschutz says the ones that are in the lake now will survive, but research has shown that the fish don’t reproduce in a lake because they need long stretches of water the trigger their spawning. So, they will survive, but she says they are not sure of their overall impact.
Bogenschutz says one thing they did not find are silver carp. Those are the fish that jump out of the water due to the vibration of boat motors and land in boats or hit skiers. Bogenschutz says the bighead carp found in East Okoboji were younger fish and they don’t know how many may be in the lake.