With highs reaching the 30s this week across the southern part of Saskatchewan, swimming in the local lakes will be tempting, but there could be danger in the water.

Sean Osmar, a Water Security Agency (WSA) spokesperson, said the current weather conditions are ideal for blue-green algae to survive and thrive. 

"As we get further into July and temperatures are rising, you'll see it in warm and stagnant bodies of water," Osmar stated.

According to the provincial government, algal blooms commonly occur during calm, hot weather in areas of lakes and reservoirs with shallow, slow-moving or still water that has sufficient nutrients.

Concentrations of blue-green algae blooms are potentially harmful to humans and animals that come into contact with or ingest water that has been contaminated by them.

Some of these adverse health effects include rashes, sore throat, cramps, nausea, vomiting, and diarrhea. 

Anyone planning to go for a swim to cool off from the heat waves this week should be on the alert for any shimmering, foaming, or colourful areas.

If a bloom is spotted near recreational beaches, folks can report it online to the Healthy Beach Program to help track where these occurrences could potentially be. 

Osmar added that it's not only direct contact or ingestion of blue-green algae that can cause symptoms.

"Even eating fish out of lakes that may have blue-green algae can make you sick," he said. 

Local animals are also at risk of being affected by and getting sick from the blooms. Pet owners and livestock producers should make sure their animals are not drinking from or cooling off in water that might be contaminated. 

Blue-green algae is naturally occurring, lasting up to three weeks, and can be pushed around the body of water by the wind.

Osmar concluded that these blooms are temporary and can dissipate with weather changes that don't suit them, but they are especially prevalent in the south.

-with edits from Marna McManus