Swimmers Fall lLL - Health Precautions Urged At Local Reservoir Due To Presence Of Blue-green Algae

By: Kw Now! Local News
| Published 07/12/2013


Blue-green Algae Found, Precautions Urged At Woolwich Reservoir

Algae Blooms Can Affect Both Humans And Pets

Warning signs are being posted around Woolwich Reservoir near Elmira advising people to take precautions because of the presence of blue-green algae in the water which can cause illness.

GRCA staff were alerted of the reservoir conditions by local residents who became ill after swimming in the reservoir. Symptoms of exposure to blue-green algae include headaches, fever, diarrhea, abdominal pain, nausea and vomiting when water is ingested by people or animals. An itchy rash may also develop if you come into contact.

Woolwich Reservoir is on the Canagagigue Creek. It was built in 1974 for flood protection and to provide water to maintain flows in the creek during dry weather.

Typically, there is little activity on the reservoir. There is no beach or public swimming area. However, there is a public trail around the reservoir that is a popular walking spot for area residents.

The Grand River Conservation Authority is advising those visiting the Woolwich Reservoir area:

o Don’t swim in the water

o Don’t use the water for drinking or any other purpose.

o Keep children and pets away from the algae

o Avoid contact with the algae

o Don’t eat fish from the reservoir

Algae blooms are a natural phenomenon. Algae feed on phosphorous, a chemical found naturally in soil as well as in manure, fertilizers and human waste.

Blue-Green Algae (Cyanobacteria)

Cyanobacteria, or blue-green algae are a concern. Under certain conditions, some strains can produce toxins that are harmful to human or animal health. Commonly found in shallow, warm, and slow moving or still water (including freshwater ponds), cyanobacteria can quickly multiply. This can lead to algal 'blooms'. Cyanobacteria blooms are frequently a bright turquoise green (hence the name blue-green algae), but colours can vary from olive or yellow-green to dark green and even purple.

The cause of algal blooms is not certain, but it is thought to be related to nutrient levels in the water.
Blooms are most common when phosphorus levels are elevated and nitrogen levels are relatively low. Like some higher plants, cyanobacteria are able to 'fix' from the air the nitrogen they need for growth.

Potential Animal and Human Health Impacts

Blue-green algae blooms often form a scum on the surface of freshwater ponds and lakes. The algae can cause skin rashes and irritation of the eyes for swimmers who come into contact with the scum. Humans that accidentally drink the water while swimming can experience nausea, vomiting, sore throat, diarrhea, or cramps.

Livestock, pets, terrestrial wildlife, and aquatic life can also be harmed.

Below: How Blue-green Algae might appear on ponds or lakes

Blue-green Algae, GRCA, Now Media