Limnology of Four Lakes in Pictured Rocks National Lakeshore
File(s)
Date
1987-12Author
Kamke, Kendall K.
Publisher
University of Wisconsin-Stevens Point, College of Natural Resources
Metadata
Show full item recordAbstract
Physical, chemical, and biological linmological data were
collected from Miners (4.6 ha), Chapel (30.5 ha), Big Beaver (308.4
ha), and Grand Sable Lakes (306.6 ha), Pictured Rocks National
Lakeshore, Michigan in the period July 1983 - May 1985. The four
lakes were well oxygenated, light to medium brown in color, with
predominantly sand substrate. Miners Lake was a eutrophic impoundment
of Miners River and strongly influenced by its discharge. Chapel Lake
was meromictic due to morphogenic and biogenic factors. Various ions
were present in excessive concentrations in its monimolimnion. The
mixolimnion was dimictic and mesotrophic. Big Beaver Lake was
mesotrophic, and due to its size, mean depth (6.8 m), and orientation
to prevailing wind was polymictic. Grand Sable Lake was oligotrophic
and stratified yearly. Chemically the lakes were circumneutral with
low to moderate buffering. Dissolved iron was present in all the
lakes. Heavy metals (Al, Pb, Hg, Zn) were not detected, or were
present in naturally low concentrations. Nutrient levels varied, but
were below levels associated with algal blooms. Water color was the
most important indicator of trophic status because levels of nutrients
and chlorophyll-a were low. The degree of substrate heterogeneity
influenced the bentic diversity among the lakes. Zooplankton fauna
was dominated by four species in the lakes although overall densities
were low. I found no evidence that anthropogenic use had
affected the lakes. The lakes are potentially susceptible to
changes in water chemistry from acidic precipitation.