People who live near Lake Micmac in Dartmouth, N.S., are going to need to find another place to cool off this summer.

Officials with the Halifax Regional Municipality are encouraging people to avoid swimming in the lake until further notice after a possible blue-green algae bloom was detected. The off-leash dog area of Shubie Park by the lake will also be closed to swimming until further notice.

"The risk advisory means that there could be toxins in the water now or later. Better to avoid contact until we have been able to confirm that the risk has passed or that there is in fact no risk," said Cameron Deacoff, a water resources specialist with the municipality.

Deacoff spotted the greenish, syrupy patch floating near the shoreline of Lake MicMac on Tuesday. He said testing will get underway on Friday to determine what the substance is and if it's toxic.

"Enjoy the park, by all means, but don't get in the water and don't let your dog get in the water," he said.

A news release sent out by the city on Tuesday stated some types of blue-green algae produce toxins during blooms, and when these blooms decay, the toxins may be released into the water, posing a risk to people and pets.

A blue-green algae advisory sign at Lake Mic Mac in Dartmouth, N.S. (David Laughlin/CBC)

Contact with blue-green algae can lead to skin irritation, rash, sore throat, sore red eyes, swollen lips, fever, nausea, vomiting and/or diarrhea, according to the release.

"If you have these symptoms, you are advised to seek medical assistance," said the release.

The risk advisory will remain in place until blooms have disappeared and post-bloom tests indicate the water is within safe limits for blue-green algae.

A warning advisory sign was put up to warn lake users not to swim, allow pets to swim or drink the water because of the possible bloom.

People who come into contact with blue-green algae may experience skin irritation, rash, sore throat, sore red eyes, swollen lips, fever, nausea, vomiting and/or diarrhea, HRM said in a news release. An algae bloom in Lake Ainslie, N.S., is shown in this photo. (Submitted by Nova Scotia Environment)

On Wednesday, the sign caught the attention of people out walking their dogs.

"From what people are saying, it's not very good for pets and anybody swimming of course," said Jenny Monk.

Mitch Dickey walks his dog at the park daily.

"I'd be awful concerned about him getting ill," said Dickey.

"I've heard some horror stories about what blue-green algae can do to dogs. It's also bad for people. But I'd hate to let him go for a swim and end up getting sick or worse."

Blue-green algae bloom has been linked to dog deaths in New Brunswick.

Oakfield Beach closed

On Tuesday afternoon, the municipality said high bacteria levels have closed Oakfield Beach at Grand Lake. It said it will continue to test the water and will announce when the beach reopens.

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