FREDERICTON (GNB) – As summer approaches, New Brunswickers are reminded to be aware of the potential health risks posed by cyanobacteria (commonly called blue-green algae), which may be present in lakes and rivers used for recreational purposes.

“We want all residents to be active and enjoy the outdoors, but we also want them to understand and consider the potential risks of exposure to blue-green algae,” said Dr. Jennifer Russell, chief medical officer of health.

Last summer, the provincial government partnered with communities and organizations to install new cyanobacteria signage at ponds, lakes and rivers throughout New Brunswick. That work will continue this summer and more signs will be installed in the coming months.

Cyanobacteria are naturally occurring bacteria found in many bodies of water. They are not normally visible, but under certain conditions, can increase in numbers to form visible surface blooms or benthic mats.

The signs will describe cyanobacteria and inform the public on how to stay safe. This information and more can also be found on the department’s cyanobacteria web page.

The signs will not replace health advisory signs and do not indicate that a cyanobacteria bloom has been observed in the body of water. If a cyanobacteria bloom is detected, a health advisory sign will be posted. A list of advisories is available on the web page. It includes the location, when the advisory was first issued and the date of the most recent confirmed bloom for a given body of water.

While most commonly blue-green in colour, surface blooms can also look green, red, or brown. Benthic mats, which can form along the bottom of lakes and rivers, can look like clumps of vegetation that can appear black, brown or dark green in the water, but when washed up on the shore they may appear brown or grey once they have dried. They can also be attached to rocks or aquatic vegetation.

The signs and the department’s webpage include examples of surface blooms and benthic mats to help the public become familiar with and identify suspected cyanobacteria.

In addition, the provincial government supports projects related to cyanobacteria, which includes research along the Saint John River and in several lakes, that is intended to better understand the distribution of cyanobacteria and potential toxins.

“While enjoying any recreational water, there are things you can do help protect yourself,” said Russell. “Algal blooms can be unpredictable, so it is important that you always check the water before entering. If a bloom is present, it is recommended that you avoid swimming or engaging in other activities that may involve contact with the water.”

Other safety advice includes:

  • Always supervise young children and pets near bodies of water.
  • Do not swallow lake or river water.
  • Bathe or shower after being in rivers, lakes or ponds.
  • Do not enter the water with open cuts or sores.
  • Always wash your hands before eating.

Pet owners are advised that benthic mats, including those that wash up along the shores of lakes and rivers, can be toxic and potentially lethal to dogs if consumed. Dogs are attracted to their odour and should not be permitted to eat vegetation along the shore or floating benthic mats. As a precaution, children and adults should not play with or handle benthic mats while wading, fishing, boating or otherwise enjoying recreational activities in the water.

The public is encouraged to report suspected cyanobacteria blooms to the Department of Environment and Local Government regional office.

As well, residents can help prevent harmful algal and cyanobacterial blooms from forming by using only the recommended amounts of fertilizers on their farm, yard and garden. Nutrients that may run off into nearby bodies of water can help algae and cyanobacteria grow more quickly than usual.

Residents should also maintain their septic system to keep wastewater from leaking and seeping into nearby bodies of water, as they too can contribute to blooms.