{both areally and with depth) indicate that multiple locations have been the sources for the high specific activity sediments deposited at the different locations in the northwest quadrant. Compared to the concentrations of radionuclides in the very fine sejiments collected in the northwestern lagoon, the high concentrations of radionuclides measured in the naturally coarse sediments from two midlagoon stations directly downstream from the region of high radionuclide concentrations cannot be explained by a linear correlation of the radionuclide concentration with the proportion of fine sediment present in the sample. Either a particle size or biogeochemical fractionation of the debris and/or radionuclides is suggested to explain this observation. Evidence that the differences in the spatial distributions of 137 Cs and 207 Bi (from those of 2394240, , 238 Pu, 24} Am an 60 Co, d 155 Eu) are partly related to their chemical properties is suggested from thier distributions in sediment cores and from differences in their distribution between the sediments and bottom waters of the lagoon. The ratios for the latter comparison were made by computing the ratio (pCi radionuclide/m= bottom water):(pCi radionuclide/g surface sediment) at each station in the Yagoon where the radionuclide concentrations in total, particulate (>0.3 pm) and soluble (<0.3 ym) fractions of bottom water samples have been measured hy other investigators. 24 The ratios for 23942405, 238pu . . Lam and 155¢, (especially those between the concentrations measured between suspended particulates and sediments) were found to be very similar at any given station in the lagoon. Compared to the actinide and lanthanid&cosfficient? for total water samples (the range across the lagoon is from 0.5 to 10), the ratios for 6069, 137¢5 and 20734 were higher, by an average of about 7.3 times for 60¢0, 22 times for 20785,