Total numbers per square meter and taxa of insects taken during a survey of headwater streams in the Toolik Lake region during the summer of 2001, Arctic LTER 2001.

A Surber sampler (25 X 25 cm frame fitted with a 243 um mesh net) was used to sample invertebrates on a single date at each site. Five replicates were taken from at least two riffles at each site. Samples were preserved in 4% formaldehyde and transported to Orono, Maine, where invertebrates were removed by hand under 15X magnification and then identified and counted. All values are the mean of five replicates and have been converted to individuals per square meter.