Minnesota Project: Development of an ecological assessment method for Minnesota...

Minnesota Project

Development of an ecological assessment method for Minnesota...

July 2007 - June 2009

Personnel

Participating Agencies

Minnesota Department of Natural Resources

The Minnesota Pollution Control Agency has encouraged the Department of Natural Resources to identify and develop two lake health indicators that could be used to assess whether Minnesota lakes are impaired as part of the Minnesota Legislature’s Clean Water Legacy Initiative to facilitate the implementation of the Total Maximum Daily Load process mandated by the Clean Water Act. Our goal is to evaluate indictors of lake health should be used for assessing the ecological integrity of lakes in Minnesota, focusing on an indicator that will complement the fish index of biological integrity (fish IBI) that has developed. Our objectives are to: (1) review the existing indicators of lake health that have been used in temperate lakes, (2) use existing data within Minnesota to evaluate the applicability and robustness of existing measures of lake health, (3) prioritize approaches across the gradient of Minnesota lake types and identify data gaps, and (4) identify an approach to complement the fish IBI method, and recommend a general framework for its use in Minnesota.

Research Publications

Research Publications	Publication Date
Beck, M. W., L. K. Hatch, B. Vondracek, and R. D. Valley. 2010. Development of a macrophyte-based index of biotic integrity for Minnesota lakes. Ecological Indicators 10:968–979. \| Abstract	April 2010	Traditional approaches for managing aquatic resources have often failed to account for effects of anthropogenic disturbances on biota that are not directly reflected by chemical and physical proxies of environmental condition. The index of biotic integrity (IBI) is a potentially effective assessment method to integrate ecological, functional, and structural aspects of aquatic systems. A macrophyte-based IBI was developed for Minnesota lakes to assess the ability of aquatic plant communities to indicate environmental condition. The index was developed using quantitative point intercept vegetation surveys for 97 lakes that represent a range of limnological and watershed characteristics. We followed an approach similar to that used in Wisconsin to develop the aquatic macrophyte community index (AMCI). Regional adaptation of the AMCI required the identification of species representative of macrophyte communities in Minnesota. Metrics and scaling methods were also substantially modified to produce a more empirically robust index. Regression analyses indicated that IBI scores reflected statewide differences in lake trophic state (R2 = 0.57, F = 130.3, df = 1, 95, p < 0.005), agricultural (R2 = 0.51, F = 83.0, df = 1, 79, p < 0.005), urban (R2 = 0.22, F = 23.0, df = 1, 79, p < 0.005), and forested land uses (R2 = 0.51, F = 84.7, df = 1, 79, p < 0.005), and county population density (R2 = 0.14, F = 16.6, df = 1, 95, p < 0.005). Variance partitioning analyses using multiple regression models indicated a unique response of the IBI to human-induced stress separate from a response to natural lake characteristics. The IBI was minimally affected by differences in sample point density as indicated by Monte Carlo analyses of reduced sampling effort. Our analysis indicates that a macrophyte IBI calibrated for Minnesota lakes could be useful for identifying differences in environmental condition attributed to human-induced stress gradients.

Presentations

Presentations	Presentation Date
Beck, M., B. Vondracek, and L. Hatch. 2011. Image analysis techniques to evaluate effects of nearshore lake development on aquatic macrophytes. 141st Annual Meeting of the American Fisheries Society, 4-8 September 2011, Seattle, Washington.	September 2011
Beck, M., B. Vondracek, and L. Hatch. 2011. Image analysis techniques to evaluate effects of nearshore lake development on aquatic macrophytes. 44th Annual meeting of the Minnesota Chapter of the American Fisheries Society, 8-9 February, Sandstone, Minnesota. (Best Student Presentation)	February 2011
Beck, M. W., B. Vondracek, and L. K. Hatch. 2010. Assessing the health of Minnesota’s lakes using indices of biotic integrity. Joint Meeting of the Minnesota Chapters of the American Fisheries Society, Society for Conservation Biology, Society of American Foresters and The Wildlife Society, 1-3 March, Nisswa, Minnesota.	March 2010
Beck, M. W., L. K. Hatch, B. Vondracek, and R. D. Valley. 2010. Development of a macrophyte-based index of biotic integrity for Minnesota lakes. 2010 International Congress for Conservation Biology, 3-7 July 2010, Edmonton, Alberta, Canada.	July 2010

Cooperative Fish and Wildlife Research Units Program: Minnesota Education, Research and Technical Assistance for Managing Our Natural Resources