Behavior of 7Be in Sargasso Sea and Long Island Sound waters

Previously reported results indicated that the standing crop of 7Be in Lake Whitney sediments was that predicted by atmospheric flux, whereas the three Long Island Sound cores were markedly deficient in 7Be. The difference between the fresh water and marine sediments could be ascribed to the greater efficiency of adsorption of reactive species on particles in low ionic strength waters observed for other nuclides such as 137Cs. If this indeed were the case then the remainder of the 7Be expected from the precipitation should be found in the Long Island Sound water column. 7Be was determined in open seawater samples and in water from Long Island Sound. The open ocean seawater standing crops were found to be compatible with those expected from precipitation data. The 7Be concentration of a Long Island Sound water sample was found to be less than 240 dpm/1000 1, which corresponds to a standing crop of less than 0.5 dpm/cm2 for a mean depth of 20 meters. These results indicate that the water column cannot satisfy the previously described deficiency, adding only 0.5 dpm/cm2 to the sediment standing crop of about 2 dpm/cm2, compared to 4 to 5 dpm/cm2 predicted from the atmospheric precipitation data. It is concluded that there is another sink for 7Be in the Long Island Sound system, possibly the salt marshes on the margins of the Sound