Type E botulism has been linked with the death of at least 200-300 common loons in the eastern basin of Lake Ontario, according to The New York State Department of Environmental Conservation (DEC).

Long-tailed ducks, grebes and gulls are some of the other species of birds that have died due to avian botulism.

Avian botulism is caused by toxins produced by the bacteria 'Clostridium botulinum'. Birds are most commonly affected by type C and type E, according to the U.S. Geological Survey. The toxin affects the nervous system and causes paralysis. Infected birds lose control of their wings and neck muscles.

USGS reports indicate that Type E botulism has killed about 100,000 bird n the Great Lakes region since 2000, according to Guardian Express.

Although, the disease has been around since many decades, researchers haven't been able to explain how the toxin ends up affecting birds.

Scientists are now analyzing from the Great Lakes and studying the distribution of birds that depend on the fishes found in the region.

 According to the DEC, two non-native species might be important links in the spread of this toxin. Clostridium botulinum can be found in mussel beds. These mussels are eaten by small bottom-dwelling fish called the round gobies. These fish are a favorite meal of many birds, including loons, and some duck species.

Investigators are assessing all possible theories that explain how these toxins end-up killing thousands of waterbirds each year.

"It's kind of like a detective story," said David Blehert, a microbiologist with the USGS National Wildlife Health Center in Madison, Wis., according to the Associated Press. "You find a body somewhere. You want to find out where the incident took place. You look for clues on the body, you find a piece of hair, a piece of fiber, and trace it back to the location and hopefully find your culprit."

DEC biologists aren't expecting any more deaths due to Type E botulism in the coming months, but have requested people living in the area to keep a look-out for dead birds washing ashore as the carcasses could spread the toxin to other animals.