Synthesis of Time-interval Changes in Trace Metals and Hydrocarbons in Nearshore Sediments of the Alaskan Beaufort Sea: A Statistical Analysis

Table 2. Summary of the mean concentrations (ng/g THg, % Fe, and g/g rest of the metals) and related statistics for the sediment trace metals (values normalized to Fe) by regions and year of sampling.. Table 3. Time-interval differences in the mean concentrations of trace metals [not normalized to iron (Fe)] in Table 6. Correlations between environmental parameters, PCA factor scores, and metals concentrations (normalized to Fe) for the combined coastal regions for the time-interval 1997 to 2003 (BS 97 and BL03 samples). Table 10. Spearman's rank analysis showing correlation coefficient matrix for total mercury (THg), methyl mercury (MeHg), granulometry and organic matter (OM) on gross sediments from Colville Delta-Prudhoe Bay, Figure 8. Cluster analysis of ln-transformed metals data (not normalized to Fe) for the study area, 1997 to 2003. Figure 9. Dendrogram illustrating the results of the cluster analysis on ln-transformed metal concentrations normalized to iron (Fe), for Colville Delta-Prudhoe Bay (Beaufort Sea, BS97) and Beaufort Lagoon (BL03).. 20 Figure 10. Score plots from PCA of the metals data (not Figure 16. Scatterplots of total polycyclic aromatic hydrocarbons (∑PAH) and total n-alkanes (∑n-alkanes) vs organic matter (OM %) and perylene against C 29 ABSTRACT The nearshore sediment trace metals and hydrocarbons data, generated by Dr. Naidu and associates, pertaining to three regions [Elson Lagoon (EL), Colville Delta-Prudhoe Bay (BS) and Beaufort Lagoon (BL), Alaskan Beaufort Sea] are consolidated, statistically analyzed and synthesized. The data comprise of the concentrations in the mud fraction of sediments (<63μm size), normalized and not normalized to Fe, of a suite of metals [Iron (Fe), arsenic (As), barium (Ba), cadmium (Cd), copper (Cu), chromium (Cr), lead (Pb), manganese (Mn), nickel (Ni), tin (Sn), vanadium (V) and zinc (Zn), and in gross sediments of total mercury (THg), methyl mercury (MeHg)] and hydrocarbons [normal and isoprenoid alkanes, triterpenoids, steranes, and polycyclic aromatic hydrocarbons (PAHs)]. The above analytes are selected because they are commonly associated with contaminant inputs from petroleum-, municipal-and/or military-related activities. Generally, the concentrations of the trace metals in the study area are below or comparable to those in world's unpolluted nearshore marine sediments. Cluster analysis on the composite database of either all the metals (both normalized and not normalized to Fe basis) or hydrocarbons show lack of discrete grouping of stations confined to the individual three regions. Significant regional differences in some individual analyte's concentrations are noted, though. Time-interval comparisons of the concentrations of metals …