Employ these new data and constants as input to the assessment program for refining the projected doses for Enewetak, Bikini and other atolls in the nothern Marshall Islands; Define the need and develop guidelines for any long-term radio-ecological surveillance on Enewetak, Bikini, Rongelap and Utirik atolls. Produce an ecological systems model for the long-lived radionuclides in these coral island environments including radionuclide transport, recycling, and fate; Evaluate the resuspension pathway as a potential! source of transuranics exposure; and Add to the data base supporting the predictive dose assessment capability. Marine-Groundwater Program The goals of this program are to investigate the rates of movement, accumulation and turnover of the transuranics and other radionuclides in various components of the marine and groundwater environments of Enewetak and Bikini Atolls and open ocean areas in the Marshall Islands. Samples are collected for radiochemical analysis from these aquatic environments in order to: Determine the concentrations of radionuclides in different tissues and organs of marine species to develop recommendations for minimizing the passage of radionuclides to human populations from the marine food chain; 13