The Boston Public Health Commission (BPHC) is asking residents to not swim, fish or boat in Jamaica Pond due to a dangerous algea bloom that can make people and pets very sick.
The BPHC issued the warning for the popular outdoor recreational space last week and said the pond is ‘temporarily closed’ to water activities.
Health officials suspect there’s a bloom of blue-green algae, also known as cyanobacteria. “Based on initial visual inspection of the pond, it appears likely that Jamaica Pond is experiencing a harmful algae bloom,” said the BPHC in a statement. “These blooms may produce toxins that can make people and pets sick. Park visitors are urged to avoid contact with the water and any areas of algae concentration, even on shore.”
Blue-green algae can form harmful blooms in lakes, ponds, and rivers that make the water murky, and can sometimes make the water look like pea soup or paint. The current suspected bloom in Jamaica Pond appears like a dull green discoloration that could be confused as otherwise safe pond water. The toxins in the algae may be present within the algae cells or in the water.
“For humans, the primary concern is ingestion of water containing blue-green algae while swimming,” continued the statement. “Direct skin contact with the blue-green algae and inhalation of water droplets containing blue-green algae or toxins is a secondary concern. For dogs, the primary concern is the ingestion of water containing blue-green algae or scum that has washed ashore or gotten onto their skin or fur.”
The BPHC suggests if you, your child, or pet comes in contact with the water at Jamaica Pond, rinse off immediately. The BPHC said contact by humans with toxins in the algae may cause skin and eye irritation, and inhalation can cause respiratory irritation and exacerbate pre-existing respiratory conditions. Ingestion of blue-green algae can cause acute gastrointestinal symptoms, such as vomiting and diarrhea. If the blue-green algae are producing toxin(s), the health effects can be more serious, especially for small pets due to their smaller body weights. Ingestion of the toxins can cause acute gastrointestinal distress and, depending on the specific toxin, can affect the functioning of the liver, kidneys, and/or neurological systems and in severe cases can result in death.
“Call your veterinarian immediately if your dog has been around an algae bloom and shows symptoms such as vomiting, staggering, drooling, or convulsions,” the BPHC statement said. “These symptoms present themselves soon after exposure. Dogs have been known to eat the scum that washes ashore and/or lick scum out of their fur. In Massachusetts and in many other states, canine deaths have been documented due to the ingestion of harmful algae.”
City health officials can not predict how long an algae bloom will last. In Florida for example, the Gulf Coast experienced an algae bloom that lasted for most of 2017 and killed scores of marine life and sickened residents with respiratory issues.
“Algae blooms may last for weeks in the summer or may disappear quite quickly,” said the BPHC’s statement.
The BPHC said they will coordinate with the Massachusetts Department of Public Health (DPH) over the coming weeks with DPH water sampling to determine when the advisory can be lifted. DPH recommends that the recreational water advisory not be lifted until two consecutive weekly samples show algal cell counts below the safe limit of 70,000 cells/milliliter of water.