Botulism Bacteria Blamed for Deaths of Waterbirds on Lake Ontario

Photo: Botulism bacteria blamed for dead loons on Great Lakes beaches. Credit: Lisa Borre.
Botulism bacteria was blamed for the death of this loon and hundreds of others like it in northern Lake Michigan last year and in eastern Lake Ontario this year. Photo by Lisa Borre

Last year, I wrote about finding the carcasses of dead loons and cormorants on the shores of a Northern Lake Michigan beach. Now officials in New York are reporting similar waterbird deaths from Type E botulism on Lake Ontario.

Sadly, finding type E botulism in waterbirds is becoming an “annual event in one or more of the Great Lakes,” according to a press release by New York State Department of Environmental Conservation (DEC). A die-off involving this many loons has not been seen on Lake Ontario since 2006.

Reports from the public and field investigations by DEC crews indicate that at least 200-300 common loons have washed ashore along Jefferson and northern Oswego County shorelines, according to the DEC statement.

In a previous post about the Great Lakes Environmental Assessment and Mapping (GLEAM) project, I used the example of the tragic death of the majestic loons to illustrate how environmental threats interact.

The factors at play include nutrient pollution, invasive species, and food chain interactions. Experts believe that rotting mats of algae generate the botulism toxin, which is picked up by filter-feeding, invasive quagga mussels, the preferred food of an invasive species of fish, the round goby. The infested fish get eaten by diving waterbirds and the deadly bacteria get passed up the food chain. That’s when people start finding dead loons washing up on the shore.

DEC is encouraging the public to report sightings of dead birds to regional DEC offices.

Lisa Borre is a lake conservationist, freelance writer, and avid sailor. With her husband, she co-founded LakeNet, a world lakes network, and co-wrote a sailing guide called “The Black Sea” based on their voyage around the sea in 2010. A native of the Great Lakes region, she served as coordinator of the Lake Champlain Basin Program in the 1990s. She is now an active member of the Global Lake Ecological Observatory Network.


  1. Sarah
    May 22, 2014, 1:48 pm

    Does this happen at a specific time of year? I found a dead waterbird partly buried in the snow this spring on a Lake Ontario beach in the Niagara region. It looked somewhat like a loon, but I couldn’t tell for certain because too much of it was buried. I thought it seemed strange because I’d never seen a loon in the area.

  2. Lai Wing Kong
    Kuala Lumpur, Malaysia.
    December 31, 2013, 12:16 am

    Sympathy to lots of animals that die with no proper reason, nowadays animals extinction and death are due to climate change and activities that related to human.