PARENT SESSION
PT10 - Depwater Sediment Investigations
Tuesday, 19 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P684) Finding the Footprint: Sunken Ships, Deep Ocean Sediments and Multivariate Analysis.
Newton, Frederick*,1, Hardin, John1, Wild, William2, Gauthier, Ron2, Johnston, Robert2, Carpenter, Arthur3, Diener, Douglas4, 1 Battelle Memorial Institute, Carlsbad, CA, USA2 SPAWAR Systems Center, San Diego, CA, USA3 Caloxy, Vista, CA, USA4 MEC Analytical Systems, Inc., Carlsbad, CA, USA
ABSTRACT- An ecological risk assessment of the potential release of polychlorinated biphenyls (26 PCB congeners) from the sunken vessel ex-Agerholm was conducted in deepwater (> 800 meters) off the coast of southern California. Heavy metals (Ag, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) expected to be found in association with sunken vessels were examined to validate the sampling techniques. Logistical constraints dictated sampling of most test (near vessel) and reference sites a year apart. Hypothesis testing using ANOVA techniques detected few significant differences between vessel and reference sites. Several multivariate statistical techniques were used to further explore data and elucidate a possible vessel - sediment signature. Indirect analytical methods (ordination and cluster analysis) included principle components analysis (PCA) and factor analysis. Multivariate direct gradient analytical techniques, including canonical ordination, were also used. Based on these analyses a distinct vessel signature was elucidated and primarily driven by physical factors (e.g., TOC and grain size) and metals (Cd and Cu).
Key words: Deepwater, Sediment, PCB, Multivariate