I don't know how true this is, but my mom used to live on Lake Michigan when she was ~7 and used to tell me how gross the lakes were before the Clean Water Act, and how amazing the turn-around. If so, it's a nice example for the jaded that government can do some things right.

Lake Michigan was fine in the 1980s (when I grew up swimming in it). Even during weather that would really churn things up the water was still fine.

Another comment mentions Zebra mussels, which have made the lakes quite a bit clearer in recent years (but not necessarily to good effect).

With the size of the Great Lakes, it wouldn't be that surprising that some bays or inlets would be clean while others were disgusting.

I don't know about Lake Michigan, but I wouldn't really have advocated swimming in the parts of Lake Ontario I was around in the '80s.

I was living in Toronto in the 1990's and I wouldn't swim in Lake Ontario if you paid me.

And anyway this is a seasonal effect brought on by a larger than usual ice content this past winter. If I read the article correctly this won't last long and run off from surrounding farms and industry will have the lake algae ridden and opaque before too long...

I wouldn't be so quick to blaim run off without evidence that this is the main cause. Diving in the ocean in northern Europe you experience the same thing: you have a choice between 4 degrees C and clear water or 15 degrees C and murky green. Runoff isn't a significant cause of plankton blooming in the North Atlantic. Temperature is.

Still, it requires nitrogen to get an algae bloom, right? Has to come from somewhere.

Phosphorus is the limiting nutrient, not nitrogen. But yes, it's nearly all from ag and wastewater.

In the ocean, iron plays the role of phosphorus.

And it looks like the evidence for run off causing algal blooms in the Great Lakes is pretty convincing.

I swam in Lake Ontario near Kingston from the mid-80's up to a few years ago and never had an issue, although after heavy rains in summer there could be pretty high E. coli load near shore due mostly to ducks and geese (solution, swim off a dock).

Fecal matter from birds--like the scads of corrmorants around Kingston--is rich in nutrients, and while agricultural runnoff can be a problem Lake Ontario doesn't suffer from it particularly, and even without it there are plenty of altnernative nutrient sources.

I have a photobook of Chicago that has a picture of north avenue beach in the 1960s with thousands of people on it.

I think a city's relationship with its waterfront has to do with what was built on land next to the water. In Toronto the lakefront was industrial until recently. In Chicago the industry was clustered along the river and the lakefront has consisted of parks and beaches for a century.

And now some of our beaches have Blue Flag certification. Incredible.

No one ever even thought about it.

This sounds made up, but my father worked for the state department that oversaw municipal water treatment (as a civil engineer, many cities on Lake Michigan draw water from the lake), so I guess I would have had some awareness of serious issues with the water.

Zebra mussels have had a noticeable effect on water clarity in Chicago harbors in the last ten years. When the light is right it's possible to see 20-30 feet down easily when the view was always previously occluded.

Aside from the detrimental effects on local species it also means that algae and weed blooms are common and it's not uncommon for harbors to be choked with weeds by August.

Not sure if all the current water clarity across the lake can be attributed to them but the change inshore has been rapid and remarkable.

You swam in Lake Michigan regularly? I remember it being bracingly COLD, even on a hot summer day.

This was on the western (Wisconsin) shore of the lake, though, which may have been colder due to upwelling from the prevailing westerly winds.

Little Traverse Bay is surrounded by some surprisingly expensive vacation homes and a high-end town center, so perhaps it's not so surprising that the bay is kept very clean.

The more expensive the land the more grass/ornamental fertilizer runoff the worse the water quality.

FWIW, I met my wife when she was living in that area. Little Traverse Bay on whe whole is a pretty affluent area. (There is some mix here, and definitely a drop in money if you move inland.) There are few manicured lawns near the bay though. Unlike Grand Traverse Bay, Little Traverse is mostly surrounded by quickly rising hills and bluffs. So while there are houses they tend to not have much in the way of yards.

I was born and raised in the Traverse City area. The Great Lakes have become remarkably clearer throughout the years. I was told that it was due to the invasive species of Zebra Mussels[1] which have no natural predators in the Great Lakes. As their population exploded, they have significantly increased the clarity of the water.

-- [1] - http://www.noaa.gov/features/earthobs_0508/zebra.html

I didn't live there, but my grandparents did and my family summered there (on Long Lake) every year from the early 80's thru the last few years. I snorkels and later dove in Lake Michigan and surrounding connected and non-connected lakes. The water definitely got more clear in the 90's and 2000's to my unscientific eye.

It's beautiful country up there. Nothing much compares, to me, to northern lower-peninsula Michigan summers.

The Little Traverse Bay is a true treasure, and yes, when I was on it two summers ago, it was crystal clear every day.

Too bad the water is freezing cold and the beaches are full of rocks.

I have friends and family who will swim in 45 degree water but it's not for me.