Scientific Context for this Study
The Section of Fisheries of the Minnesota Department of Natural Resources is leading a collaborative effort to monitor and record biological and chemical changes that may occur over long periods in a sample of lakes that are representative of the state’s most common aquatic environments. The collaborative effort is referred to as “SLICE: Sustaining Lakes In A Changing Environment” and our lab one of the partner groups involved in this effort. More details of the SLICE Lakes effort is on-line at:
Chironomidae are a family of aquatic flies (Diptera) that are exceptionally species rich and useful in documenting water and habitat quality in freshwater systems (Ferrington, 2008; Ferrington et al., 2008). In Minnesota lakes, these flies serve as the primary food sources for a number of sport and forage fish species, and they are essential links in nutrient cycling and energy flows in freshwater systems. In our lakes they are usually the most biologically diverse group of aquatic insects and are considered to be reliable indicators of water quality, habitat structure and climate conditions
They can be very species rich and numerically abundant in healthy aquatic habitats, with more than 100 species known to occur in some streams in Minnesota, and at least 80 species in some urban lakes of the Twin Cities (Rufer & Ferrington, 2008). We anticipate encountering more than 100 species across the Tier 1 SLICE Lakes.
Scope of Research
We will use an innovation field collection technique during this research that has been shown to be efficient at detecting species, effective in determining phenological patterns, and is highly cost-effective (Ferrington, 1987; Ferrington et al., 1991; Bouchard & Ferrington, 2011). The method relies on collections of surface-floating pupal exuviae (SFPE) that are concentrated on the water surface by wind and wave action. Both wind direction and intensity of wave action can change over time, consequently we will collect at several pre-determined points in each slide lake (3-5 depending on bay structure and habitats) to ensure that collections are representative of the species emerging on each sample date.
Bouchard, R. W., Jr. and L. C. Ferrington, Jr. 2011. The effects of subsampling and sampling frequency on the use of surface-floating pupal exuviae to measure Chironomidae (Diptera) communities in wadeable temperate streams. Environmental Monitoring and Assessment 181:205-223.
Ferrington, Leonard C. Jr. 1987. Collection and Identification of Floating Pupal Exuviae of Chironomidae for Use in Studies of Surface Water Quality. Prepared for U. S. EPA, Region VII, Kansas City, KS as SOP No. FW130A. 39 pp. + appendix.
Ferrington, L.C., Jr. M. A. Blackwood, C.A. Wright, N. H. Crisp, J. L. Kavanaugh and F. J. Schmidt. 1991. A Protocol for Using Surface-Floating Pupal Exuviae of Chironomidae for Rapid Bioassessment of Changing Water Quality. pp.181-190. In: Sediment and Stream Water Quality in a Changing Environment: Trends and Explanations. IAHS Publication Number 203. 374 pp.
Ferrington, Jr., L.C., M.B. Berg, and W.P. Coffman. 2008. Chironomidae. Chapter 26, pp. 847-989. In: R.W. Merritt, K.W. Cummins, and M.B. Berg, eds. An Introduction to the Aquatic Insects of North America. 4th Ed., Kendall/Hunt Publishing Co., Dubuque, Iowa.
Rufer, M. M. and L. C. Ferrington, Jr. 2008. Sampling frequency required for chironomid community resolution in urban lakes with contrasting trophic states. Boletim do Museu Municipal do Funchal (História Natural) No. 13:77-84.