The Minnesota Department of Natural Resources is closing islands on five Minnesota lakes to prevent the spread of Newcastle disease.
The virus has killed about 1,200 double-crested cormorants, pelicans, and ring-necked gulls this summer.
The islands are in Minnesota Lake, Pigeon Lake, Marsh Lake, Lake of the Woods, and Lake Kabetogama. Officials still are waiting for results from Mille Lacs Lake.
DNR veterinarian Erika Butler says the idea is to protect domestic poultry in the area.
"It's pretty easily spread through contaminated clothing, vehicles, people, which is our reason for closing these off. We don't want people to go out there and pick it up on boots, and then bring it somewhere else," Butler said.
Newcastle disease is not a major concern for humans, although it can cause a mild conjunctivitis and flu-like symptoms.
Some of the islands that will be posted are used for duck-hunting. The closures will be in effect until late fall.