South Portland Parks and Recreation has posted signs warning beachgoers of a toxic blue-green algae bloom in Hinckley Park Credit: CBS 13/WGME

For the fourth year in a row, a toxic blue-green algae bloom has been found at a popular South Portland park.

On July 8, South Portland Parks, and Recreation said it found an active cyanobacteria bloom in Hinckley Park.

Blue-green algae is a type of photosynthesizing bacteria called cyanobacteria. It exists in all Maine lakes but is harmless in low concentrations.

However, when the population of this bacteria explodes during an algal bloom it can sometimes produce toxins that, when ingested, can kill dogs, according to Scott Williams, executive director of the Lake Stewards of Maine. It can also harm humans.

The algal bloom is toxic so beachgoers are warned to stay away, and keep kids and pets away from the water.

South Portland has posted signs around the park to inform people.