News

Gizzard Shad, Known To Disrupt Fisheries And Compete With Native Fish, Found In East Lake Okoboji

Tue 8-29-2017

            (Orleans)-- A species of fish known to disrupt fisheries and compete with native fish like bluegill and perch has been found in atleast one of the Iowa Great Lakes. Mike Hawkins, a fisheries biologist with the Iowa Department of Natural Resources tells KUOO news crews discovered 26 3 to 5 inch-long gizzard shad in East Lake Okoboji while doing some routine sampling August 11th. Hawkins says gizard shad were not sampled in West Lake Okoboji or Big Spirit Lake. He says they aren't sure how they got here...Gizzard Shad01 

            "They certainly could have been introduced by somebody. That happened in the past in other places in the state of Iowa and in the Midwest where somebody either inadvertently or intentionally introduced these species. These also could have come in maybe during some high water events before the electric fish barrier was in place and existed in a real low level that we didn't detect and the last couple of winters have allowed them to get a spawn that survived, and so we may just be seeing some remnants of fish that entered at an earlier time."

Hawkins says gizzard shad can reproduce in large numbers. He adds gizzard shad do not tolerate long winters and are usually found in bodies of water further to our south. Hawkins says the recent mild winters are apparently now allowing them to survive further north.

Hawkins adds it's illegal to possess live gizzard shad in the state of Iowa...Gizzard Shad02 

"We don't want gizzard shad being introduced into any of our system, either our natural lakes or any of our constructed lakes or county areas. It is illegal to move gizzard shad. In reservoir systems they have caused some pretty significant damage to fisheries. In some cases those fisheries have had to be renovated to actually remove the gizzard shad, so in a natural lake system like the Iowa Great Lakes we hope it doesn't, they don't cause that level of a problem."

Hawkins says the DNR will continue to closely monitor the population of gizzard shad in the Iowa Great Lakes.

He reminds anyone that it's also illegal to stock fish in any public water in Iowa. The public is asked to report any such activity by contacting their local conservation officer or by calling the Turn-in-Poachers hotline at 1-800-532-2020.