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LONGITUDINAL ZONATION OF CHIRONOMIDAE (INSECTA: DIPTERA) ALONG THE ST. CROIX RIVER

LONGITUDINAL ZONATION OF CHIRONOMIDAE (INSECTA: DIPTERA) ALONG THE ST. CROIX RIVER

B.E. Schuetz, Department of Entomology, University of Minnesota
L.C. Ferrington, Jr. Department of Entomology, University of Minnesota

The Saint Croix River's status as a national scenic waterway makes it an excellent setting to test theories related to composition and dynamics of communities of aquatic organisms at large spatial scales. Chironomidae surface floating pupal exuviae (SFPE) are being collected from April 2007 until October 2007 at 17 sites representing a large spatial gradient of the Saint Croix River from the upper reaches near Gordon Flowage to its confluence with the Mississippi River. The project is designed to investigate the emergence phenology and longitudinal zonation of Chironomidae as a function of the River Continuum Hypothesis and other literature-based models that predict patterns of community composition over large spatial scales. Specimens will be slide-mounted and identified under a compound scope to lowest practical level. The resulting data will be used to calculate metrics based on taxonomic composition, species richness, and α and β diversity. In addition to testing models at large spatial scales, this research will provide baseline data that can be used in long term biomonitoring of this valuable natural resource. It is expected that protocols and conclusions from this research can be applied to monitoring programs in other national parks and river systems.

Suggested Reading

Coffman, W.P. 1989. Factors that determine the species richness of lotic communities of Chironomidae. Acta Biologica Debrecen Oecologica Hungarica 3:95-100

Ferrington, L.C., Jr., M.A. Blackwood, C.A. Wright, N.H. Crisp, J.L. Kavanaugh, & F.J. Schmidt. 1991. A protocol for using surface-floating pupal exuviae of Chironomidae for rapid bioassessment of changing water quality, p. 181-190. In: Sediment and stream water quality in a changing environment: trends and explanations. Vol. 203. IAHS Publication Number 203. Copy available at: http://www.entomology.umn.edu/midge/Ferrington_etal.1991.pdf