122 7. RECOMMENDATIONS (1) It is recommended that profiles of unsupported 210 Pb concentrations, at other lagoon stations which have accumulations of finely divided sediments, be made to better understand the horizontal redistribution process. (2) Additional sediment sampling is recommended to better define the the areal distribution of radionuclides around the craters, especially in the northwest quadrant of the lagoon. (3) Because the distribution of radionuclides between the sediments and bottom waters of the lagoon appear to be a valuable means of understanding the initial distribution of radionuclides in the water column, it is recommended that future sediment sampling be accompanied by a sampling of the adjacent bottom waters. (4) An investigation of the physical-chemical properties of the parti- culate material and associated radionuclides suspended in the water column is recommended in order to better understand their origins, behavior and cycling in the lagoon ecosystem. An interesting approach to this problem would be to measure, in pariculate material separated (by size) on millipore type filters used in series, the weight, proportion of organic material, and the concentrations of radionuclides on the different sized filters collected at a few selected lagoon and crater stations. Such measurements might be supplemented by leaching experiments and by S.E.M. photography to identify the particle types. (5) Measurements of the total alpha radioactivity of a coralline sample which has a known alpha disintegration rate is recommended to empirically verify the presence of the fraction of alpha emitting radionuclides not accounted for in the Bravo crater sediment analyzed.