The Boston Public Health Commission has issued a health advisory and halted all water activities at Jamaica Pond because of a recent growth of toxic algae in the water, officials said.
Visitors to the pond will not be allowed to swim, boat, or fish, or let their dogs swim in or drink from the water for as long as the algal bloom persists, the health commission said in a statement.
Known as cyanobacteria, the blue-green algae that has formed in the pond creates a murky discoloration, which may make the water look like “pea soup or paint,” according to the health commission.
Contact with the algae can cause skin or eye irritation, and ingestion of a large amount can cause vomiting or diarrhea. Symptoms are more severe for pets, Interim Chief of Staff P.J. McCann said Monday night.
McCann said that excess nutrients and warm weather are part of what causes the algae to grow.
“We know that warm weather can exacerbate the situation,” he said.
He said that to his knowledge, this has not happened before, and no person or pet has been harmed so far.
Beginning on Wednesday, the Boston Health Commission plans to review water samples over the coming weeks, and will not lift the ban until safe levels exist for more than two consecutive weeks.