413 



could accumulate and long-term effects might occur. Additional regional stations were 

 located at sites where drilling fluids and cuttings might accumulate over time. These 

 include the heads of Lydonia and Oceanographer Canyons, the Mud Patch south of Cape 

 Cod and Rhode Island, and just above the edge of the Continental Shelf south of the lease 

 area. Another station was located in a high energy erosional area at the top of the Bank 

 in about 35 meters of water. 



In order to detect near-field impacts of drilling discharges on the benthic 

 environment, two groups of sampling stations were established in close proximity to two 

 exploratory drilling operations. A group of three stations was located within 200 meters, 

 and approximately 2,000 meters upcurrent and downcurrent of the drilling site in Block 

 fflO located in about llfO meters of water (Stations 16, 17 and 18 in Figure 2). A larger 

 array of 29 stations was located in a radial pattern around the exploratory rig site in 

 Block 312 in 80 meters of water (Figure 3). This rig site corresponds to Regional Station 5 

 in Figure 2. Stations were located within 200 meters and at distances of 0.5, 1, 2, <» and 6 

 kilometers from the rig site. An over-sampling strategy was used here. Nineteen of the 

 stations were designated as primary stations, and all samples from these stations were 

 analyzed. The other ten stations were secondary stations, and samples from them will be 

 analyzed, if needed, to aid in interpretation of impacts observed at the primary stations. 



All stations were sampled four times per year on a seasonal basis. During the 



first year of the Program samples were collected in 3uly and November, 1981 and 



February and May, 1982. At each station, six replicate biology samples and three 



2 

 replicate chemistry samples of undisturbed bottom sediments were collected with 0.04 m 



2 

 and 0.1 m Van Veen grab samplers, respectively. Subsamples of these were taken for 



analysis of carbon-hydrogen-nitrogen (CHN) and sediment grain size. Biology samples 

 were sieved through 0.5 and 0.3 mm screens and preserved in buffered formalin. 

 Chemistry samples were frozen. 



Bottom photographs were taken at each station to document the presence of 

 animals living on the sediment surface (epifauna) and bottom living (demersal) fish, and in 

 an effort to detect evidence of accumulation of drilling mud and/or cuttings. Measure- 

 ments of water column hydrography (salinity, temperature, dissolved oxygen) were taken 

 at all regional stations. Dredge and trawl samples were collected at up to three regional 

 and three site-specific stations to obtain fish and mollusc (ocean quahog Arctica islandica ) 

 samples for chemical analysis and to obtain representative specimens of epifauna and 

 demersal fish for a voucher collection to be used in identifying species observed in bottom 

 photographs. 



