Blue-green algae is seen in this Aug. 28, 2013  file photo taken near Black Bridge, located just north of St. Albans Bay Park. The multi-colored mass, spreading nearly the length of the park’s shoreline and elsewhere in the bay, was by many accounts the largest ever. This close-up photo shows the distinctive color of the algae, which can be toxic to people and has been known to kill pets if ingested. (Messenger file photo by Sondra Sarra)

Blue-green algae is seen in this Aug. 28, 2013 file photo taken near Black Bridge, located just north of St. Albans Bay Park. The multi-colored mass, spreading nearly the length of the park’s shoreline and elsewhere in the bay, was by many accounts the largest ever. This close-up photo shows the distinctive color of the algae, which can be toxic to people and has been known to kill pets if ingested. (Messenger file photo by Sondra Sarra)

ST. ALBANS — The Vermont Dept. of Health has issued a high alert for blue-green algae in St. Albans Bay, where water quality is already described as “disgusting” by a watershed official.

The alert is the result of state experts observing large amounts of blue-green algae along with dense scum or highly colored waters.

No testing for toxins has been done, but the water is not considered safe for recreational use. Residents should stay out of the water and keep their pets away, too.

High alerts have also been issued for portions of Missisquoi Bay in Quebec.

A low alert has been issued for the Larry Greene Fish and Wildlife Access in Swanton. The water is considered safe for recreation, but users are urged to avoid dense accumulations or scums of algae.

“It’s pretty disgusting,” said Steve Cushing, president of the St. Albans Area Watershed Association.”It’s not what a lake should look like.

“It’s all along the shoreline,” he added. “It’s another disaster going on there.”

If the weather stays warm and calm, Cushing said he expects the blooms to continue.

This is one of the worst summers for the bay Cushing has witnessed: “People are very upset. They really are,” he said.

Blue-green algae, properly known as cyanobacteria, releases toxins shown to be fatal for animals and potentially harmful for humans. Swallowing water containing cyanotoxins, including microcystin, can cause nausea, dizziness, diarrhea, vomiting and cramps. Rashes are also common.

A Canadian study of people living along Missisquoi Bay who were exposed to cyanotoxins from blue-green algae, published in January, found possible links between the toxins and irritation of the upper and lower respiratory tract, eyes, ears and skin as well as muscle pain, headaches and mouth ulcers.

On Monday, Toledo, Ohio lifted a ban on drinking water from Lake Erie, initiated when microcystin from blue-green algae were found in the city’s water supply.

Like the blooms in Lake Champlain, those in Lake Erie are fed by phosphorous runoff, much of it from agriculture. According to the New York Times, Ohio officials have relied solely on voluntary measures to reduce phosphorous into Lake Erie, just as Vermont has with Lake Champlain.

The current bloom in Lake Erie is neither the largest on record nor the first to shut down a municipal drinking supply. In 2011, algal blooms in the lake stretched 120 miles from Toledo to Cleveland.