Multiple CoLocated Sediment Cores

Sites in the Hudson Basin that have yielded well-dated sediment cores in the past are typically revisited every few to several years to extend contaminant chronologies. This procedure, collecting multiple sediment cores spaced several years apart at the same site, was first applied to the

Hudson at our site just downstream of the Statue of Liberty (site 7; Fig. 26.1; Bopp and Simpson, 1989). The initial core, collected in 1979, provided samples dating back to the mid-1950s. A second core collected in 1984 contained several samples that overlapped and confirmed the contaminant chronologies from the first core. Since 1984, we have extended the chronologies at this site through analyses of surficial samples that contained detectable levels of 7 Be collected in 1989,1994,1998, and 2001. We also conducted similar monitoring at four other mainstem sites in the harbor and in the Kill Van Kull (site 11; Fig. 26.1) and Newtown Creek (Bopp and Walsh, 1994; Chillrud, 1996; Robinson, 2002).

Jamaica Bay cores collected in 1982 and 1988 were used to develop trace metal and chlorinated hydrocarbon chronologies (Bopp et al., 1993). Pb, Zn, Cd, Cr and Hg were each strongly correlated with Cu suggesting that the primary source of these metals to Jamaica Bay was from waste water treatment plants. Cu, Pb, and Zn were analyzed

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