Field Design and Sampling Method

lake and trees

Assessment of Biodiversity of Chironomidae in Tier 1 SLICE Lakes of Minnesota

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 1987Ferrington et al. 1991Bouchard & Ferrington 2011). When used in lake monitoring, 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.

The project will consist of two years of fieldwork. Collections of SFPE will be made from a broad array of habitats at each of the pre-determined sample sites in each SLICE Lake. Collections of SFPE provide a spatially and temporally integrated sample of chironomid emergence, and will allow us to efficiently determine species composition and community emergence phenology for each lake.

SFPE supplies
Samples of SFPE will be collected monthly from early spring (soon after ice-out), through early fall. GPS readings will be made for each of the collection sites, and habitat descriptors (e.g., substrate and vegetative cover, water temperature pH conductivity and dissolved oxygen) will be recorded.  These abiotic habitat descriptors will be linked to individual species and site records, in construction of electronic databases. Similarly, data for collections made during the study will be linked to GIS shells of respective lake and maps of sample sites will be constructed.

Click on the appropriate link below to access a section that describes in more detail the methodology for collecting SFPE, and discusses relative merits and cost-effectiveness compared to other types of collections for inventorying Chironomidae faunas in lakes.  We have recently published a video of our lab processing procedures (Kranzfelder et al. 2015) that can be viewed for details related to sample sorting, specimen preparation, labeling and curation.


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.

Kranzfelder, P., Anderson, A. M., Egan, A. T., Mazack, J. E., Bouchard, Jr., R. W., Rufer, M. M., et al. 2015. Use of Chironomidae (Diptera) Surface-Floating Pupal Exuviae as a Rapid Bioassessment Protocol for Water Bodies. J. Vis. Exp. (101), e52558, doi:10.3791/52558.