ALBANY, N.Y. (AP) New York conservation officials are the deaths of birds found along the shores of Lake Ontario since mid-October.

The Department of Environmental Conservation says preliminary examination indicates type E botulism is the likely cause.

Further testing is being done.

Similar deaths have occurred in fish-eating waterfowl and other birds on Lake Ontario since 2002, usually in the fall.

Conservation officials say tens of thousands of birds have died in the Great Lakes.

Loons, grebes, gulls and certain duck species are the principle victims in outbreaks.

Affected birds typically drown after becoming paralyzed by botulinum toxin in fish they eat, most commonly round goby, an invasive species that gets toxin by feeding on invasive mussels on the lake bottom.