16 



2.0 METHODS 



2.1 Sample Collection 



Six cores were collected on 6 August 1991 on board the M/V Beavertail using a 

 gravity corer and PVC core liner. All cores were successfully recovered, with only a loss of 

 a few centimeters of material from the first core (MQR1). Cores were recovered as the 

 vessel was positioned near the center of the mound. 



After cores were recovered on deck, they were split with a handsaw, and PVC 

 shavings were removed from the exterior of the core before sampling. The cores were 

 described, photographed, and sampled. Because the top 1 m of MQR appeared homogenous, 

 samples were taken at the surface, at 30 and 100 cm, and above and below distinctive visual 

 boundaries between lithologic intervals. Sediment was sampled using teflon-coated utensils 

 rinsed in sea water and distilled water, and placed in 250 ml I-Chem precleaned glass jars for 

 chemical analysis. Another subsample of sediment was placed in plastic bags for grain size 

 analysis. Samples were stored in ice chests at approximately 4° C and delivered to the NED 

 laboratory. 



Sediment samples were delivered to the NED laboratory on 9 August 1991. The 

 samples were stored refrigerated until the time of analysis. Core samples were analyzed for 

 grain size using ASTM methods (Table 2-1); pesticides, polychlorinated biphenyls (PCBs), 

 priority pollutant metals, and polynuclear aromatic hydrocarbons (PAHs) according to EPA 

 protocols (Table 2-1). 



Following the August MQR coring survey, additional surface grab samples were 

 taken on 17 December 1991. Samples were collected on board the R/V UCONN using a 0.1 

 m 2 teflon-coated Van Veen grab sampler. Five separate grab samples were taken near the 

 center of the MQR mound. Subsamples were taken with teflon-coated utensils from 

 approximately the top 2 cm of the grab sampler. No sediment in contact with the surfaces of 

 the grab was included as part of the sample. All utensils in contact with sediment samples 

 were rinsed with methanol or isopropanol, distilled water, and sea water between each grab 

 sample. Sediment for volatile organics and metals analyses were placed in one precleaned I- 

 Chem 250 ml glass jar to be stored frozen. Sediment for semivolatile analyses were placed 

 in another 250 ml glass jar to be stored refrigerated before analysis. Grain size samples 

 were stored in plastic bags. Samples were stored in ice chests at approximately 4° C before 

 delivery to the NED laboratory. Sediment surface samples were delivered to NED on 18 

 December 1991. Surface samples were analyzed for volatile organic compounds (VOCs) 

 using EPA methods (Table 2-1) on 30 December 1991. 



Sediment Core Chemistry Data Summary from the MQR Mound, August and December 1991 



