Lake winnipeg is large and changes colour. As summer progresses, parts of it slowly shift from milky mahogany to bluish green, and by August, it can be emerald in places, as vivid as a golf course. From space, it looks as though someone poured a giant kale smoothie onto the Manitoba landscape.
What the satellites are picking up are billions of tiny aquatic organisms that, individually, are usually visible only under a microscope. They can be long and thin, like a sliver of grass, or short and round, like a squishy stress ball. They might fan out like miniature ferns, or form star patterns as intricate as a snowflake. Some have little tails to move through water; others simply float. All are considered species of algae, and they feed on nutrients such as nitrogen and phosphorus. When too many nutrients pour into a lake, these life forms grow in wild unhinged abundance.
Among the many kinds of algae that thrive in Lake Winnipeg are cyanobacteria, or blue-green algae. One of the most successful micro-organisms on the planet, they once performed a billion-year photosynthesis project that helped generate the oxygen in our atmosphere. When those ancient algae died, they formed the oil deposits we use to power cars and jets. Today, toxins in blue-green algae can kill a dog that’s splashing around in an afflicted lake—sometimes in under an hour.
In August 2015, biologist Eva Pip travelled to Hillside Beach in the south basin of Lake Winnipeg—about an hour-and-a-half drive from downtown Winnipeg—to look for neurotoxins in the algae. She’d been going out to various beaches every three days since spring, collecting samples and testing them for beta-methylamino-L-alanine, or BMAA—an amino acid that cyanobacteria can produce and that has been linked to degenerative brain diseases including Amyotrophic Lateral Sclerosis (ALS) and Parkinson’s.
The beach was full of people. Hillside is a sandy, shallow inlet. There are no boardwalks, no shacks selling ice cream—only families with small children, and locals carrying coolers. Grandparents lounge in beach chairs, and parents loll on colourful towels, watching their kids splash one another with turbid water.
Pip cut an eccentric figure as she sloshed out of the lake, wearing hip waders and carrying water samples—and even more so when she started addressing the young children, cautioning them not to play with the thick, viscous mats of dead algae that had washed up on shore.
She wears her hair in a loose bun, so that the tops of her ears peek out through the brown and slightly grey wisps that spray down to her shoulders, and her eyes are bright and blue. But her mild appearance is misleading. She has become Lake Winnipeg’s own weeping Jeremiah—or, in a modern version of that archetype, its saddest and angriest scientist.
Lake Winnipeg is the tenth-largest freshwater lake in the world. For decades, it has suffered from severe eutrophication, a process that results when aquatic ecosystems are overwhelmed with nutrients, usually from local runoff. But disagreements persist over how serious the problem is: it might spell doom for the lake’s food web and pose dangerous health risks to those who use it, as Pip argues, or it could just be a cosmetic blight that threatens tourists’ and cottagers’ enjoyment of the water. It’s either an ecological disaster or a late-summer nuisance—or something in between. Many who live by the lake are now accustomed to the green sludge and occasional stench, and they seem just as likely to dismiss the problem as join a campaign to fix it.
Pip remembers the first time she collected samples on Lake Winnipeg, back in 1961, when the water was so clear she could see the kaleidoscope of colours formed by pebbles on the lakebed. Since then, the lake has suffered a barrage of attacks: fertilizer that’s washed directly into the waterways from nearby fields; overflow from municipal sewage systems; the contents of faulty septic tanks. All of it ends up in Lake Winnipeg.
Toxic algal blooms have been wreaking havoc all over North America. Three years ago, an eruption of algae in Lake Erie left more than 500,000 water customers in Toledo, Ohio, without drinking water. Last summer, blue-green slime coated rivers and beaches in Florida, prompting a state of emergency in four counties. In July 2016, 130 people reported vomiting, diarrhea, headaches, and rashes after coming in contact with algae-infested Utah Lake.
On that August day two years ago, Pip claims to have found BMAA levels of 306 micrograms per litre—“a very high concentration,” she said. There are hardly any standards regulating BMAA in Canada, because it isn’t studied much here. But BMAA testing isn’t a settled matter in other countries, either. Gregory Boyer, a biochemist at the State University of New York, has, for example, called into question the very accuracy of such measurements. He points out that some methods make it easy to confuse BMAA with other amino acids of the same molecular weight. He also believes BMAA isn’t present in Lake Winnipeg, because his work didn’t show it. For her part, Pip argues that no one wants to admit how toxic Lake Winnipeg algae might be because the economic fallout of a crippled fishery and tourism industries would be severe. A poisoned lake is one thing, a poisonous lake quite another.
Pip’s biggest quarrel is with government scientists. “I’ve been extremely disappointed by how apathetic the community has been,” she told me. In 2016, she retired from the University of Winnipeg, where she’d studied more than 650 lakes and contributed to more than 123 published studies. “You’re supposed to behave the way everybody else does, and then you’re one of them,” she says. “But if you’re outspoken, then you’re an alarmist.”
Her outspokenness has made Pip perhaps the most controversial scientist in Manitoba. Mention her name among researchers who study algae or work to improve the water quality of Lake Winnipeg, and you’ll likely trigger strong responses ranging from irritation to concern. Some regard her crusading—especially her penchant for making dire pronouncements that win the attention of news outlets—as deeply off-putting.
Karen Scott is the educational program coordinator for the Lake Winnipeg Research Consortium, which helps researchers collect data on the lake from sixty-five monitoring locations. Over the last few years, she has taken on the role of myth buster. She meets with community groups to explain why messages such as “The lake is dying” and “The lake is toxic” aren’t accurate, no matter how often the media reinforces them.
First, the lake is technically too alive: there are too many nutrients feeding too much algae. Second, such statements create the false impression that the toxins are ubiquitous, when in fact they’re present only in some algae and then mostly in late summer if the algae are blooming. Calling the whole lake toxic, says Scott, is like saying a forest is poisonous because poisonous mushrooms grow in it.
Like Pip, Scott works to make people think more carefully about their relationship with water. But she operates at the other end of the sensationalism spectrum. When Scott talks to the public, she tries to convey a simple message: “Water moves.” We may see it for only the fraction of the second it takes to travel from the faucet to the drain, but it travelled far to soak our toothbrushes, and has farther yet to go. Lake Winnipeg, in other words, isn’t just the large body of algae-packed water in Manitoba: it’s part of an enormous watershed that spans about a million square kilometres between the Canadian Shield and the Rocky Mountains. Water moves, past farms and factories, through pipes and ditches, in and out of towns and cities. Sooner or later, it all ends up in the same place, along with everything it picked up along the way.
How much people value water often depends on whether it’s moving away from or toward them. For the farmers and city dwellers upstream, what’s out of sight passes easily out of mind. But for the Indigenous people and cottage communities near the lake, what the others ignore is bright green and hard to miss.
More than 400 kilometres long from bottom to top, Lake Winnipeg consists of two distinct sections: a smaller south basin, home to a handful of Indigenous communities and most of its public beaches and cottages, and a larger north basin that includes part of the pickerel and whitefish fishery.
Despite its enormous size, Lake Winnipeg is a small remnant of a much bigger lake that once covered the entire province of Manitoba and large sections of Ontario, as well as parts of Saskatchewan, Minnesota, and North Dakota. Lake Agassiz was formed at the end of the last ice age by meltwater from a glacier that was four kilometres thick and so heavy it depressed the Earth’s crust by 100 metres. As the glacier melted, the land started to spring back, causing some of the water in the region to travel north, toward Hudson Bay and the Arctic Ocean.
When Lake Agassiz drained out to sea, it left behind a flattened landscape full of lakes and bogs. Today, after a summer rainstorm, the fields look as if they’re trying to return to their former sogginess. Water collects in every indentation, filling the ditches and forming dirty brown ponds amid otherwise lush crops.