The samples are collected by suspending a substrate (block of Styrofoam) in the lake, in about 10 feet of water, for a month.  The substrate collects near shore suspended sediment, algae, etc.  After a month you retrieve it, scrape off the slime and analyze it for chlorophyll a to determine the amount of algae that has grown on it.  PWD is  in the process of analyzing the 2006 samples, but this picture is about all you need to know. 

This is a striking illustration of the impact of development on water quality.  The worst sample is from Kettle Cove.  The Frye Island sample is less green and cloudy, which is good.  Not surprisingly, the clearest sample is from Lower Bay.  Development really does matter.