For the last half a century, scientists at Heidelberg University’s National Center for Water Quality Research have been attempting to measure the pollution in the rivers and streams that feed Lake Erie. Decades of monitoring have led to an inescapable conclusion: phosphorus runoff, primarily from agricultural and other industrial sources, coupled with climate change, is feeding explosive cyanobacteria growth, known as algae, in the warm, shallow waters of one of Michigan’s five Great Lakes.
Lake Erie was so polluted during the 1960’s that TIME magazine warned it was “in danger of dying by suffocation.”
Local businesses, as well as state and national policymakers, participated in a massive clean-up effort, bringing, the lake back from the brink. Recently, however, algae blooms have once again tainted western Lake Erie with unhealthy, sometimes toxic, green slime.
Why is this happening?
Well, consider the conditions that cyanobacteria need to thrive—warmish water and nutrients like phosphorous and nitrogen. The farming industry around the Great Lakes uses large amounts of these chemicals, a lot of which get washed downstream into larger bodies of water. Back in the 1960’s, monstrous blooms were common due to large nutrient releases from agricultural and industrial facilities as well as sewer systems.
There’s evidence that the warming atmosphere, which holds more moisture and delivers more-intense rain events, which, in turn, cause more nutrients to be pushed into lakes and coastal waters, has caused the resurgence of troublesome algae in the lake and around the world.
The region the Great Lakes are located in, known as the Midwest, has become warmer and warmer as of late. Temperatures in the midwest have already risen over 1.5°F since 1900, with the increase speeding up in the last 30 years.
Algae blooms occur regularly in Lake Erie in the late summer and fall—government meteorologists even forecast and track them—though this year to a degree that has been particularly impressive. This year’s bloom was first reported in July in Maumee Bay, but has since spread eastwards and northwards within the lake’s western basin, along the shore of Michigan, Ohio, and Ontario.
Toledo, Ohio Mayor Paula Hicks-Hudson wrote in a letter sent to Trump last week about the concerns the entire region has.
“There is something very wrong with our country when our rivers and lakes turn green,” she wrote. “As I look out my office at a green river, I can tell you one thing: the status quo is not working.”
It might look pretty from the skies, but the bloom contains Microcystins, which is a type of freshwater cyanobacteria which produces toxins that can contaminate drinking water and pose a risk to human and animal health, including irritation to the skin, respiratory distress, liver damage, and flu-like symptoms. Along with this, the process of eutrophication, which takes place when the algae enters the water and really begins to gain strength, can leave lakes starved of oxygen, not to mention a foul odor.
It has proved fatal to livestock.
There’s also research, for whatever it’s worth, that certain chemicals in cyanobacteria make fish spontaneously change sexes.
The bottom line is, algae love warm water, and with water temperatures rising across the globe, these baleful blooms likely will become more common. It’s something Great Lakes environmental officials will have to think hard about.
[Featured Image by Haraz N. Ghanbari/AP Images]