Crystal Lake

Crystal lake iconCrystal lake fyke removel in winterCrystal Lake is located within the Northern Highland-American Legion State Forest, Vilas County.

It is a seepage lake with predominantly sand substrate. It has a surface area of 36.7 hectare, 2.3 kilometers of mostly undeveloped (campground) developed shoreline and a maximum depth of 20.4 meters.

Crystal Lake represents one extreme in the groundwater input gradient, with a marked predominance of precipitation inputs. Groundwater accounts for only 5% of input water, yet, because groundwater is more concentrated chemically than precipitation, groundwater accounts for substantial amounts of incoming solutes. For example, about 50% of the silica budget comes into the lake via groundwater, exerting a major influence on primary production.

The lake is an oligotrophic, dimictic lake high in the landscape with minimal groundwater input, a light attenuation coefficient of 0.24 per meter (average ice-free Secchi depth of 8 m), a mean depth of 11.4 m, and a maximum depth of 20.4 m. Crystal Lake is circular with a shoreline development factor very close to 1.0. The littoral zone is fairly homogenous and is dominated by sandy substrate with low macrophyte and coarse woody habitat densities. The fish community has been historically dominated by pelagic yellow perch. However, yellow perch drastically declined after the detection of rainbow smelt in 1985.


Lake Information

Long Term Data

Chemical Limnology





Organic Carbon



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Physical Limnology

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Selected Projects

Rainbow smelt are an invasive fish species that was first detected in the Laurentian Great Lakes in the 1920’s and have since spread to numerous inland lakes. As of 2005, rainbow smelt have invaded 24 inland Wisconsin lakes and have the potential to spread to many more. In Wisconsin’s Northern Highland Lake District, rainbow smelt have been associated with several negative impacts on lake food webs.  For instance, rainbow smelt have been associated with shifts in zooplankton community structure, reductions in yellow perch densities, extirpation of ciscoes, and walleye recruitment failure.

Our primary goal in the Microbial Observatory is to advance the understanding of lake bacterioplankton, whose diversity and population dynamics are currently the least understood off all freshwater planktonic organisms. Through identification and characterization of predominant bacterial populations in a suite of strongly contrasting lakes, we will gain significant new insight into the ecological roles of bacteria in diverse freshwater ecosystems.