It’s part of a pattern that’s only going to increase with global warming, John Smol, a professor at Queen’s University, told CTV News Channel, painting a picture of lakes shrinking, others flooding, fish species disappearing and algal blooms killing underwater plants. . “We are sleepwalking to disaster,” he said Sunday, saying we must act now to slow those changes. “I wouldn’t say it’s too late, but it’s very, very late.” When people first hear that our summers are getting longer, at first “they think it’s great,” he said. But with this widespread warmth comes increasing instability in ecosystems, including the world’s more than 100 million lakes. “One of the classic things for people who might be in their cottages this weekend or soon, they’re going to start seeing probably more algal blooms, especially blue-green algal blooms — that’s the scum on the lake surfaces,” Smol said. . . “They probably didn’t see what they usually did in the past.” He explained that blue-green algae, which are cyanobacterial blooms, “can have serious health effects, not only for us, but for other organisms as well.” Cyanobacteria thrive in warm water and can grow faster when temperatures rise, meaning climate change may help provide the ideal conditions for increased algal blooms. These algal blooms can block sunlight for those living below the water’s surface, as well as consume oxygen that would otherwise feed underwater plants, leading to dead zones in our lakes. They can even make water toxic by leaching excess oxygen. We’ve seen the impact of a cyanobacterial bloom before on one of the Great Lakes – the water supply to Toldeo, Ohio, was shut down for three days in 2014 by an algal bloom in Lake Erie. But how climate change is affecting our lakes goes beyond algae. “That’s just one of the things you can see visually,” Smol said. “Many fish habitats are severely affected, especially deep-water fish that like cold water.” Increased algal blooms, cold-water fish losing their natural habitats, shrinking winter ice and declining levels of dissolved oxygen in the water are covered in a new study that looked at how climate change is affecting lakes. Smol, along with experts from York University and Bangor University in Wales, reviewed current research on freshwater lakes from around the world in order to create a coherent picture. The report, published in mid-July in the peer-reviewed journal BioScience, found that climate change is transforming our lakes in many ways, depending on where on the planet they are. In Ontario, algal blooms have been reported in lakes as early as November, the study notes. The study also found that global lake evaporation is expected to increase by 16 percent by the end of the century. “In an area with more evaporation, the water level will drop,” Smol said. “If you’re in an area that now has more runoff, say you get your water from high mountain areas that are driven by melting glaciers, well, right now you might have a lot of water, even too much water. “They’re like water towers, these glaciers in the mountains — once they melt, they kind of slow down and cut off the water supply a lot.” Loss of ice cover on lakes can also lead to greater salinity in the water itself, according to the study, which affects aquatic life. Smol said the varied effects climate change is having on our lakes affect not only the plants and animals in the water, but also the cultural, recreational and economic activities of the people who live off that water. “For many peoples, freshwater fish is an important source of protein, not just in Canada, but around the world, and if some of your precious fish are getting squeezed by this warming, it comes down to food security,” he said. . These impacts are often exacerbated by indigenous communities, who may rely on fishing and other water-related activities. “The last thing many indigenous communities need is more problems with their water supply,” Smol said. Our inaction on climate change is disappointing to scientists like Smol, who said we haven’t prepared enough for how our world is changing. “The fact that I’m still angry means I still have hope,” he said. “But it’s too, too late. “There have been some positive things that have been supported by different governments, but we need to move quickly and get in that direction. The longer we wait, the fewer and fewer options we have. And really, now, choices for our grandchildren and great-grandchildren. More changes are coming and we need to prepare for them.”