Dead birds line a portion of Allenwood Beach just outside of Wasaga Beach, Ontario Saturday Oct. 22, 2011.
As many as 6,000 dead birds have washed up on the shores of Georgian Bay in Ontario, say authorities, who believe botulism may be to blame.
Ontario Provincial Police Constable Peter Leon said Saturday the number of dead waterfowl is estimated to be between 5,000 and 6,000.
The dead birds are scattered along a nearly three-kilometre stretch north of the community of Wasaga Beach, said Constable Leon.
Federal and provincial officials believe the cause of the death is a form of botulism, apparently from the birds eating dead fish, he said.
A spokeswoman for Natural Resources Minister Michael Gravelle says staff in his department are monitoring the situation and planned to be at the scene on Sunday to collect more samples. Two weeks ago the Ministry of Natural Resources issued a news release saying the death of large numbers of fish and wildlife on the Great Lakes is not uncommon at certain times of the year. Georgian Bay is on Lake Huron.
Small-scale die-offs caused by botulism occur annually around the Great Lakes, with the last large-scale one happening in Lake Ontario in 2007, the ministry said.
According to public health agencies, no cases of human illness have been attributed to outbreaks of botulism in the Great Lakes.
Type E botulism toxin is produced by a bacterium that lives in lake bottom sediment, and under certain conditions it begins producing the toxin, which then enters the aquatic food chain, according to the ministry. Birds who eat affected fish can die.
Health Canada says proper cooking and handling of food eliminates the botulism toxin.
Police say people in the area are being advised to keep a close eye on their children and pets to make sure they stay away from the dead birds.