1. Conclusion -Velocity affects the temperature, pH and DO of a stream; the greater the velocity, the greater the water quality -The positive correlation seen between the HBI, diversity and velocity indicate the better the water quality, the richer and more diverse the fauna -Because of these correlations, inferences of stream health may be made though the use of biotic indices Gastropods and Macroinvertebrates as Biological Indicators of Water Quality in SE Wisconsin Watersheds Student Investigator: Deanna Nickey Mentor: Dr. Dale Splinter University of Wisconsin – Whitewater Department of Biological Sciences and Geography and Geology Introduction Freshwater macroinvertebrates have served as excellent indicators of water quality for over a century. As opposed to the strictly physico-chemical approach to water quality of which merely indicates conditions present at the moment of sampling, the examination of macroinvertebrate populations and distributions gives a more extensive representation of stream conditions, both past and present. As all organisms have varying levels of tolerance to environmental stressors, Gastropods and other macroinvertebrates are indicative of water quality due to their very specific habitats, oxygen and feeding requirements, and mobility issues that come with living in aquatic environments. It is the purpose of this research to attain greater knowledge and understanding of the effects of water quality on freshwater environments, and thus the distribution and abundance of the organisms within them. Future Research This study is part of a long-term project that has been underway since 2008, and is to be continued indefinitely. Performing several sampling runs at each site is highly recommended to strengthen the validity of results and allow for more in depth statistical analyses. Sampling in both the Spring and Fall months as opposed to only the Fall will give a better overall look at macroinvertebrate assemblages and water quality. Results -DO, pH and velocity are positively correlated, while temperature is inversely correlated to all. As velocity increases, DO and pH increase, while temperatures decrease - A positive correlation between the Hilsenhoff Biologic Index, diversity and velocity exists -Low tolerance macroinvertebrates were not found in high numbers in sites with poor water quality parameters present -All sites varied in composition of macroinvertebrate assemblages as well as in field and water quality parameters Scores for all indices ran for each site as well as overall ranking score -Using Spearman’s Rank Correlation it was found that relationships between velocity and the following quality parameters show strong positive correlation: DO, pH, HBI, and Simpson’s Diversity index. -Negative correlations were seen only in regard to temperature and the above mentioned parameters. Methods Sites were selected and transects were made dependant upon similarity of habitats and ease of access Invertebrate samples were collected using a Hess sampler Water quality parameters (pH, DO, conductivity, temperature, etc.) were collected using a YSI 556 Multi-Probe System Velocity and maximum water depth across the transect was measured using a Type AA Current Meter Turbidity measured with turbidity tube Macroinvertebrates were taken to the lab to be sorted and identified to the lowest possible taxonomic level using the appropriate dichotomous keys The Hilsenhoff biotic index and two water quality indices were performed for each sampling site to determine the health of the stretch of stream Simpson’s and Shannon-Wiener diversity indices were performed to determine the diversity of organisms found at each site Sites were ranked for each test performed and an average of scores was used to assign an overall health rating for each site Discussion -Site 4, Bluff Creek #2, shows the highest scores in both water quality indices and HBI. Simpson’s also indicates that this site has the highest diversity -BC 2 also has the highest velocity measurement, because velocity is tied to many other parameters, this indicates that velocity may then have a significant effect on the richness and diversity of the stream -Site 3, Bluff Creek #1 shows the lowest scores in water quality indices and HBI. Both Simpson’s and Shannon’s Diversity Indices indicate low diversity in this stretch of stream -results indicate the slowest velocity of the sites, with high temperatures and low DO and pH -Both Sites 1 and 2 indicate relatively similar environmental circumstances, with water quality and diversity scores midway between those of Bluff Creek 1 and 2 -Velocities of these sites were also very similar and were mid-range those of Bluff Creek 1 and 2 Acknowledgements I would like to thank the UW-Whitewater Undergraduate Research Program for providing the funding for this research, as well as Dr. Dale Splinter, Dr. Rex Hanger, Dr. Kerry Katovich, Dr. George Clokey, and Simon Schmidt for their assistance and guidance throughout the research process. Study Sites Riffle habitats of two local streams within the Rock River Basin were sampled for water quality parameters and invertebrate assemblages. The stretch of Whitewater Creek from which we sampled flows through agricultural land and the City of Whitewater between Site 1 & Site 2. Anthropogenic effects between the Bluff Creek sites on the other hand are minimal. Sites from L to R: Whitewater Creek #1 (Site 1), Whitewater Creek #2 (Site 2), Bluff Creek #1 (Site 3) and Bluff Creek #2 (Site 4) Macroinvertebrates found most commonly throughout all sites. From top left: Gammarus pseudolimnaeus, Coleoptera Elmidae stenelmis, Diptera Nematocera Tipulidae, Planorbia gyraulus, Trichoptera Hydropsychidae macrostemum, Physa spp., and Ephemeroptera Baetidae procloeon.