3. 4) Monitoring chemical and hydrologic characteristics of selected existing and newly-installed wells as is deemed necessary for construction of the most useful model of atoll hydrology. 5)" i Continued evaluation of tide signals and water levels in the ocean and lagoon and on the reef to determine exterior forcing functions for island groundwater movement. 6) Incorporation of existing data and partial models into an overall model describing the hydrology, geochemistry and species residance times in the atoll environment, and ultimately predicting environmental half-lives for the various radionuclides in the different ecosystem "compartments." that Visits to Bikini atoll have provided valuable data on location and have additionally provided extremely valua- ble opportunities to test and validate observations or models originating in the Enewetak study. We propose to continue such participation in any Bikini atoll survey/research visits. . With the loss of LCU support, we anticipate that major field trips to Enewetak will be made only 2 or 3 times per year; these will be supplemental, however, by the work of the on-site technician and occasional 1-2 man visits. Bikini trips will be undertaken when joint use of ships of opportunity is feasible. 15. Relationship to Other Projects: This project is directly integrated with the LLL Enewetak-oriented projects (V. E. Noshkin and W. Robison, P.I.'s). The total output of the combined projects is directed toward a complete description and predictive model of the biogeochemical cycies and processes controlling radionuclide distributions and transport in the atoll environment. In addition, there is strong interaction between the hydrology aspect of this study and the DOE-funded lagoon circulation study (S. V. Smith and E. D. Stroup, P.I.'s), with both projects directly concerned with tidal characteristics and cross-reef transport of water and water-borne species. The two UH projects and the Robison LLL project currently support a joint-use field technician at Enewetak to provide ongoing support for all projects between major field trips. Logistic support and scientific coordination is shared with the Mid-Pacific Marine Lab. 16. also Because tropical storm Nadine Technical Progress in FY 1978: during January, 1978 Enewetak inflicted significant damage on scheduled during trips and forced cancellation of research that period, FY 78 results are running approximately 3 months behind the anticipated schedule. It is questionable whether a7