DNR officials say St. Croix River fish deaths not unusual
Officials now say the deaths of hundreds of fish on the St. Croix River appear to be seasonal and there's no cause for alarm.
Minnesota Department of Natural Resources biologists tested oxygen Wednesday in the waters on the Wisconsin border near Stillwater. And they found the levels to be adequate.
Spokesman Harland Hiemstra says the fish apparently froze in the ice down from the surface and it's probably not something that just happened recently.
An angler reported the deaths on Tuesday.
Most of the fish killed were gizzard shad, related to the herring family.