New Brunswick's health department is warning people about the risks of blue-green algae in the St. John River.

They say there's evidence of algae in that area but it shouldn't deter people from enjoying the water.

Sometimes though, it requires a few extra precautions, like the bucket Cole Wight fills with a soapy detergent and water.

It is where he washes every life jacket at after being used on the water at Second Nature Outdoors.

"Every boat that comes off of the water gets cleaned with soap and clean water, same with every life jacket and PFD that we have," said Wight, the operations manager. "It's mandatory for all campers and staff to wash their hands after coming off from water activity and we encourage all our rentals to do the same."

Wight says these measures have become "second nature" at the summer camp and boat rental facility. It's all about being safe on and off the water.

"We're always inspecting the water to see if we find any blooms or any evidence of cyanobacteria," Wight said. "If we can identify that, then we know those areas of which to avoid when we're going out."

This week, public health says they've found evidence of blue-green algae in a 100-kilometre stretch of the St. John River, from Woodstock to Fredericton.

"Is it possible that it's in other places along the St. John River?" said Dr. Cristin Muecke, New Brunswick's Deputy Chief Medical Officer of Health. "Possibly, and we would update as we get more evidence that comes in."

The algae can form surface blooms which can be a blue-green, or red, brown or yellow.

They can also appear on the bottom of a lake or river as a "mat."

Those mats can break off, and float or wash up along the shoreline and are usually black, brown or dark green.

Two weeks ago, a dog died after swimming in the river. It's suspected the algae was the cause.

"What we want people to do is like putting on a seat belt when you get into a car," Muecke said. "Get into the habit of certain precautionary steps anytime you enter a lake/river or other water body. Never swallow lake or river water if you can help it. It's advisable not to go in with open cuts or sores and you should make it a habit of rinsing off anytime you're in a water body and you come out again."

That's a checklist Second Nature Outdoors has been doing for some time.

"We're taking every precaution we can think of to combat the issue or at least protect against it while still being able to be active and outdoors and enjoying the beautiful Wolastoq River that we have right at our windows," Wight said.

Public health also says people shouldn't be scared to enjoy the river -- just take some precautions.

With files from CTV Atlantic's Laura Brown.