© 2021 Maine Public
Play Live Radio
Next Up:
Available On Air Stations
Environment and Outdoors

Marine Officials Monitoring Algae Bloom In Casco Bay

State officials are monitoring a large algae bloom in Casco Bay that stretches from around Chebeague Island to Phippsburg.

Kohl Kanwit, director of the Maine Department of Marine Resources Bureau of Public Health, says Karenia mikimotoi is a nuisance species that turns the water rusty brown and can have a foul smell. But she says it has no effect on human health and safety, either by swimming or eating seafood caught in the water.

Kanwit says, if the bloom gets large enough, it can harm marine organisms.

“As the bloom declines it can cause low oxygen levels and essentially suffocate marine organisms, but if the bloom isn’t large enough to cause that effect then generally it’s fairly benign,” she says.

Kanwit says Karenia is typically found in warmer waters than off Maine. She says there was a similar large bloom of Karenia in 2017 that may have killed some soft-shell clams.

Kanwit says officials aren’t sure how Karenia showed up in Maine or why there’s been such a big bloom this year.