Table 3. Analytical methods for trace and major elements in sediment samples and limits 

 of detection. 



Symbol Element Analytical Method Method Detection Limits 



560 

 0.01 

 2.9 

 0.08 

 1.2 

 0.77 

 16 



0.008 

 5.0 

 0.42 

 0.28 

 6.2 

 6.9 



600 

 5.0 

 16 

 2.3 



GFAA = Graphite Furnace Atomic Absorption 

 CVAA = Cold Vapor Atomic Absorption 

 FAA = Flame Atomic Absorption 

 COLOR = Colorimetric 



Benthic Communit y Analyses 



Sample collections. Benthic infaunal samples were collected at all three stations at each 

 of the five sediment sampling sites that were sampled for the chemical and bioassay 

 analyses. Five replicate samples were collected at each station. All collections were made 

 in February 1987 by SAIC. Samples were collected using a modified 0.1 m^ Van Veen grab. 

 The samples taken for benthos analyses were randomly interspersed among those taken for 

 the chemical/bioassay analyses. They were treated separately and individually and not 

 composited. The samples were sieved in the field using a 1-mm screen. The retained 

 material was fixed in formalin for 48 hours and returned to SAIC, La Jolla, California. 

 Samples were delivered to the laboratory at MEC for processing, identified only by site, 

 station, and replicate designation. 



Laboratory processing. Laboratory processing of the samples has been performed thus far 

 for samples from four of the five collection sites; the samples from the OA site were 

 deferred for later analyses. Benthic samples received at MEC were logged onto an inventory 

 data sheet. Container identifications on this sheet were used to track samples from receipt 

 through laboratory processing to computer data input. Once in the laboratory, samples were 

 transferred from formalin to 70 percent alcohol for preservation. The majority of the 

 biogenic debris (worm tubes, etc.) in each sample was identified. Organisms were sorted into 

 major and minor taxonomic groups (e.g., crustaceans, echinoderms, molluscs, polychaetes, 

 nemerteans, sipunculids, etc.) using stereoscopic dissecting microscopes. A laboratory 

 supervisor reviewed the procedures, including sample sorting, handling, and labeling that 

 were followed by the experienced sorters. 



16 



