Landscape Position Project at North Temperate Lakes LTER: Benthic Invertebrate Abundance 1998 - 1999

Benthic invertebrate assemblages of 32 lakes were surveyed as part of the Landscape
Position Project. We used modified Hester-Dendy colonization substrates to sample benthic
invertebrate communities. Each sampling device consisted of a 3"x3" top plate, alternating
layers of course and fine mesh, a ''choreboy'' commercial scrubbing puff, alternating layers
of coarse (6.35 mm) and fine (3.18 mm) black plastic mesh, and a 3"x3" bottom plate. Two
Hester-Dendy samplers were set at a depth of one meter on each of three substrate types
(cobble, sand and silt) within each lake for four weeks in late June through late July in
either 1998 or 1999. Within each lake, areas of different substrate types were identified
using WI-DNR depth contour lake maps, and substrate type was verified by direct observation.
Different substrates were sampled to account for invertebrate associations with specific
substrate characteristics. Lake order was determined using a modification of the method of
Riera et al. (2000). Lake order is a numerical surrogate for groundwater influx and
hydrological position along a drainage network, with the highest number indicating the lake
lowest in a watershed. Riera, Joan L., John J. Magnuson, Tim K. Kratz, and Katherine E.
Webster. 2000. A geomorphic template for the analysis of lake districts applied to Northern
Highland Lake District, Wisconsin, U.S.A. Freshwater Biology 43:301-18. Sampling Frequency:
one survey on each lake in late June through late July of 1998 or 1999 Number of sites: 32