Water, Bottom Deposits, and Zooplankton of Fern Lake, Washington1

Water, sediments, and zooplankton from unproductive Fern Lake were compared with those from highly productive Bay Lake and with data from the literature. In all cases, values from the Fern Lake system were in the lower or lowest range of conductance and concentration values. Consistently higher values were found in the Bay Lake samples. These differences may account partially for the productivity differential between Bay and Fern Lakes, but a major factor may be the difference in the flushing or the retention time of the lakes, as determined by the ratio of total precipitation on the watershed to lake volume. This ratio has been estimated as 26 for Fern Lake and 4.8 for Bay Lake.