This will test the hypothesis that the former marsh has maintained consistently higher accumulation rates for analytes since 1978 compared with the non-impacted marsh. Core locations will be selected in undisturbed sites with similar water depth, substrate composition, and distance from farm lands. They will be stored in the dark at 4 C and sectioned in 1 cm intervals within 24 hours. Subsequent analyses will be performed on each interval. Comparing accumulation since 1990 with the accumulation from 1978 to 1990 will also test whether the marsh continues to filter farm runoff or is saturated.
Likely contaminants are sediments, carbon, inorganic nutrients and pesticides.
The social science portion of this work will set this natural experiment in its 120 year governmental, economic, and social context. By projecting the implications of the research findings, the study will propose recommendations for programs such as the Army Corps of Engineer permits under Section 404 of the Clean Water Act, USDA Natural Resource Conservation Service programs, and EPA regulations on water pollution from nonpoint sources.