You are here:
ASSESSMENT OF RISK REDUCTION STRATEGIES FOR THE MANAGEMENT OF AGRICULTURAL NONPOINT SOURCE PESTICIDE RUNOFF IN ESTUARINE ECOSYSTEMS
Citation:
Scott, G. I., M. H. Fulton, D. W. Moore, E. F. Wirth, G. T. Chandler, P. B. Key, J. W. Daugomah, E. D. Strozier, J. Devane, J. R. Clark, M A. Lewis, D. B. Finley, W. Ellenberg, AND K. J. Karnaky Jr. ASSESSMENT OF RISK REDUCTION STRATEGIES FOR THE MANAGEMENT OF AGRICULTURAL NONPOINT SOURCE PESTICIDE RUNOFF IN ESTUARINE ECOSYSTEMS. TOXICOLOGY AND INDUSTRIAL HEALTH 15(1-2):200-213, (1999).
Description:
Agricultural nonpoint source (NPS) runoff may result in significant discharges of pesticides, suspended sediments, and fertilizers into estuarine habitats adjacent to agricultural areas or downstream from agricultural watersheds. Exposure of estuarine fin fish and shellfish to toxic levels of pesticides may occur, resulting in signifcant declines in field populations. Integrated pest management (IPM), best management practices (BMP), and retention ponds (RP) are risk management tools that have been proposed to reduce the contaminant risk from agricultural NPS runoff into estuarine ecosystems. Field studies were conducted at three sites within coastal estuarine ecosystems of South Carolina (SC) from 1985 to 1990 that varied in terms of the amount and degree of risk reduction strategies employed. An intensively managed (IPM, BMP, and RP) agricultural treatment site (TRT) was studied for pesticide runoff impacts. From 1985 to 1987, there were minimal (some IPM and BMP) management activities at TRT, but from 1988 to 1990, TRT was managed using an intensive risk reduction strategy. A second unmanaged agricultural growing area, Kiawah (KWA), was also studied and compared with TRT in terms of pesticide runoff and the resulting impacts on grass shrimp (Palaemonetes pugio) and mummichogs (Fundulus heteroclitus). A third, non-agricultural, reference site (CTL) was used for comparing results from the managed and unmanaged agricultural sites. In situ toxicity tests and field samples of the grass shrimp populations were conducted at each site and compared in terms of survival and the effectiveness of current risk reduction strategies. Significant runoff of insecticides (azinphosmethyl, endosulfan, and fenvalerate) along with several fish kills were observed at TRT prior to the implementation of rigorous risk reduction methods. A significant reduction of in stream pesticide concentrations (up to 90%) was observed at TRT following the implementation of strict NPS runoff controls,