There's something wrong with Lake Erie. Every summer when the water heats up it turns a thick soupy green, especially at the western end from Toledo to Sandusky and Point Pelee, Ontario.
The waves look like this or even worse.
The green is not good. It's caused by Microcystis algae which produces toxins that kill fish and harm humans. The algal bloom was so bad in 2014 that the Toledo Water Authority told their 500,000 customers not to drink the water and not to wash dishes with it.
The bloom reaches it peak in autumn. You can see the green muck from outer space in this satellite photo from September.
These algal blooms are triggered by warm water containing excessive nutrients: nitrogen from sewage and/or phosphates from fertilizer. In this century the water is warmer and it contains a lot of phosphorus flushed into the lake by heavy rain. Cleveland.com explains that "The Maumee River contributes half of all phosphorus in the lake, with about 85 percent of it from fertilizer runoff." (The Maumee enters the lake at Toldeo.)
We know how to fix this problem. We've done it before.
Back in 1969 Lake Erie was plagued by pollution, toxic algal blooms and dead fish. One of its tributaries, the Cuyahoga River, caught fire in Cleveland. Thanks to the Clean Water Act and the EPA established by President Nixon, Lake Erie was cleaned up quickly and stayed that way for 30 years.
Now the lake is in trouble again. Michigan has already declared the lake impaired but Ohio officials are hesitating to do so because "they don't want to scare away swimmers and boaters." Meanwhile people see and smell the algae and they're already staying away.
This 2013 video from KQED tells the story.
(photos by NOAA Great Lakes Environmental Research Lab on Flickr; video by KQED on YouTube)