Estrogen Equivalents of Surface Water in the Upper Chesapeake Bay Watershed (2008 - 2011)

Intersex in small- and largemouth bass has been observed in the upper Chesapeake Bay Watershed since 2003. This observation is indicative of exposure to estrogenic endocrine disrupting chemicals. In order to complement biological data sets and better identify the spatial and temporal nature of this end-point, discrete grab water samples were collected throughout the upper Chesapeake Bay Watershed for the evaluation of estrogenic activity. Data reported here are estrogenicity values derived from bioassay screening of OASIS-HLB extracts discrete grab water samples. Estrogenicity was determined using a bioluminescent yeast estrogen screen. Here we report estrogenicity data for selected sites in the Chesapeake Bay water shed collected between 2008 and 2011.