Officials blame a long stretch of hot, dry weather for killing fish in some Wisconsin waters.
Last week the Wisconsin Department of Natural Resources announced fish kills in four southern counties.
Nearly 2,000 fish, including walleye and channel catfish, were reported dead at the base of Lake Sinissippi near Hustisford in Dodge County. Another 500 fish -- mostly carp and walleye -- died in Rock River in Dodge County.
The DNR is investigating two other fish kills, at Beckman Mill Pond in Rock County and Yahara River in Dane County.
The Beloit Daily News reported the department said fish kills are normal this time of year. As temperatures rise and less rain falls, water and oxygen levels decrease in rivers, lakes and ponds, making it harder for fish to survive.