Wife and I looked at a cottage on a nice looking lake last year in the spring. Took a look at it on google earth in a late summer view. Completely covered in algae. Investigation revealed about 15 miles upstream from where the feeder creek enters the lake, an industrial plant of some sort had been sued for contamination of the creek, a couple lakes downstream, and a bunch of other stuff. The fish in the lake had a do not consume warning from the state. Houses on the lake were selling for cheap, and that's how we found out why. Sad.