Detection of a disease that strikes various waterfowl has prompted the closure of islands in two southern Minnesota lakes, officials announced Friday.

The state Department of Natural Resources (DNR) is closing the islands in Minnesota Lake, near Mankato, and Pigeon Lake, west of the Twin Cities near Dassel, to waterfowl hunters and other lake users.

"Early goose season starts on Saturday; that's why we need to get this out today" to hunters, said Erika Butler, a DNR wildlife veterinarian. Trespassers caught on the islands will be subjected to ticketing, Butler added.

The closures come after the National Veterinary Services Laboratory in Ames, Iowa, confirmed the disease, called Newcastle, from samples collected during the cleanup of dead cormorants in early August.

The islands will remain off limits until the risk of spreading the disease has diminished, the DNR added.

Islands in other lakes throughout the state could face the same fate. Results from samples submitted from bird die-offs are pending. Some of those lakes include Mille Lacs; Johanna near Glenwood; Pelican near Brainerd; Chautauqua and Pelican near Fergus Falls; and Wells near Faribault.

Butler said the DNR has been seeing the disease pop up in two-year cycles starting in 2008.

Newcastle disease rarely affects humans, but it can occasionally cause conjunctivitis, a relatively mild inflammation of the inner eyelids, according to the Minnesota Department of Health.

Minnesota Lake's restricted island is near the western shore and is home to a large water bird nesting colony. The DNR said that temporarily lowered water levels have exposed the lake bed, providing a land route to the island.

Newcastle is a viral disease that most commonly infects cormorants, but also gulls and pelicans. Signs of infection include droopy head or twisted neck, lack of coordination, inability to fly or dive and complete or partial paralysis. Young birds are most commonly affected.

Infected wild birds can potentially transmit the virus to domestic poultry if there is contact.

The state Board of Animal Health is recommending that all poultry producers act to protect their operations.

Those actions include restricting visitors and their vehicles; controlling movements associated with the handling and disposal of bird carcasses, litter and manure; and monitoring poultry flocks for any signs of illness.

Paul Walsh • 612-673-4482