2011 Annual Report 1a.Objectives (from AD-416) The objective of this research project will be to evaluate the influence of nutrient and pesticide mixtures on the biota within agricultural headwater streams in the midwestern United States. 1b.Approach (from AD-416) To fulfill the objective of this project, a three tiered approach will be taken. a) We will initiate and conduct a multi-scaled evaluation of the prevalence of endocrine disruption in fishes in the midwestern United States. Specifically, this research component will consist of two parts – a three year study within St. Joseph River watershed study sites and a large scale one year study encompassing ten watersheds. This will involve the use of physiological and morphological biomarkers to measure the degree of endocrine disruption in selected fish species within the St. Joseph River watershed. This component will be conducted in FY 2011 and FY 2012 in conjunction with the ecological field sampling and the streamside biossays. b) We will initiate and conduct streamside bioassays at selected locations in the St. Joseph River CEAP study sites in FY 2011 and FY 2012. The streamside bioassays will enable us to expose laboratory reared fishes and invertebrates to actual nutrient and pesticide mixtures that occur in the study watersheds. The test organisms have not been experienced prior exposure to nutrient and pesticide mixtures. Thus the streamside bioassays enable us to evaluate how survival, growth, and reproductive characteristics of “naïve” stream organisms respond to the different nutrient and pesticide mixtures that occur among our study watersheds. c) We will conduct ecological sampling of the St. Joseph River watershed study sites in FY 2011 through FY 2013 as described in Smiley et al. (2008) and Smiley et al. (2009). The additional three years of data collection will result in an eight year database on nutrients, pesticides, fishes, and invertebrates. 3.Progress Report During FY11 we conducted year two of stream-side bioassays at three sites to assess the effects of exposure to water from agricultural ditches on the biology of fathead minnows. During FY11, research in the Conservation Effects Assessment Project study area has provided projects for three masters students in biology at Indiana-Purdue University at Fort Wayne. Preliminary analyses of relationships among water chemistry, habitat variables and aquatic communities have been made and were presented at professional meetings during FY2011. Activities of this project are monitored through annual reports, periodic meetings, phone calls and e-mails.