It has been discovered that water temperature has no effect on blue-green algae blooms.

 It has been discovered that water temperature has no effect on blue-green algae blooms.

Even though the majority of cyanobacteria blooms in Canada's lakes occur during the hottest parts of the summer, water temperature appears to have little to no effect on the growth of these potentially toxic bacteria, also known as blue-green algae. The journal Harmful Algae published details of this discovery, which was made by an international research team that included scientists from Universitie Laval.

Using information from 464 lakes in North and South America, researchers from eight nations, including Dermot Antoniades, professor at Universitie Laval's Department of Geography, and Sylvia Bonilla, visiting professor at the Biology Department of Université Laval and professor at the Universidad de la Repblica in Uruguay, reached this conclusion.

        

These bodies of water run along a 14,000 kilometer north-south gradient from Tierra del Fuego in Argentina to Ellesmere Island in Nunavut. They are found in regions ranging from equatorial to polar climates," explains Prof. Antoniades, who is also a researcher at Laval University's Center for Northern Studies. The researchers found correlations between blue-green algae biomass in these lakes and various environmental factors. What are their conclusions? "There was no clear correlation between the latitude of these lakes, their position in the climate gradient, and the biomass of the cyanobacteria that lived in them. Temperature alone did not affect the biomass of cyanobacteria," said Dermott-Antoniad. Instead, the analysis showed that the most important factor explaining changes in cyanobacterial biomass in the Americas was the concentration of phosphorus in the lake water. "Nitrogen abundance was also affected, but was most pronounced in lakes less than 3 meters deep," the researchers said.

Because summer is the time of year when nutrient inputs from natural runoff, lake sediments, and human activities are at their peak, cyanobacteria blooms commonly occur in our latitudes, according to Antoniades. Even in extremely hot conditions, cyanobacteria blooms cannot occur without phosphorus and nitrogen. In starkly cold climates, on the other hand, they can thrive. ".

One of the coldest inhabited areas in the world, Cornwallis Island's Resolute Lake, had blooms in the past, as Professor Antoniades and his team have in fact documented. He says, "Wastewater from the airport and military base was bringing nutrients into this lake.

Possible connections between cyanobacteria blooms and temperature increases brought on by human activity have received a lot of attention. He suggests that it might be a bit excessive.