SPRINGFIELD, Ill. (AP) — Several states from the Great Lakes region have teamed up to reduce invasive fish species that have grown in population in recent years.

The Illinois Department of Natural Resources joined state agencies from Indiana, Michigan and Minnesota on Wednesday to complete an "invasive fish surveillance exercise" in Calumet Harbor. Federal wildlife agencies also assisted. The harbor is located on Chicago's South Side.

Agency officials used intensive netting and “electro-fishing” techniques to find invasive aquatic species. The exercise was said to be the first of its kind. The effort comes after governors from the Great Lakes region in April signed an agreement to combat invasive species.

The exercise also reached other near-shore areas of Lake Michigan in Illinois and Indiana.