Over the past 30 years there have been a number of groups that have wanted to change Clear Lake dramatically and they range from dredging the lake to a depth of more than 100 feet to spraying the lake with a herbicide to kill the weeds and algae.  Actually, in comparison to the surrounding lakes the fish have less mercury than Lake Berryessa and Lake Pillsbury. The mercury in the lake comes from the old mercury mine near Rattlesnake Island. It was on the Super Fund for cleanup and a lot has been done. Down through the years there have been a multitude of suggestions to change Clear Lake and they range from rerouting the Eel River through Clear Lake to flush it out, to treating the lake with thousands of gallons of aluminum sulfate to rid the lake of algae and even dredging the lake to a depth of more than 100 feet.