Habitat diversity on a scale of a few meters to several kilometers leads to 

 species diversity. 



Surficial sediments at each benchmark station were analyzed for trace 

 metals (barium, cadmium, copper, chromium, lead, mercury, and zinc), 

 hydrocarbons (aromatic and aliphatic), and PCBs. Scallops (muscle and 

 viscera), cancer crabs (hepatopancreas, claw/tail tissue, and eggs), and 

 tilefish (dorsal musculature) were subjected to the same analyses. Sediment 

 and animal-bound PCBs were below the levels of detection (0.005 ppm) prior to 

 drilling; subsequent analyses were not made (PCBs are not a component of 

 drilling muds and cuttings). Concentrations of petrogenic hydrocarbons (FI, 

 FII) were all undetectable before and after drilling. Trace metal 

 concentrations in the surficial sediments and in crabs and lobsters remained 

 relatively constant over time. 



We did not find any effects from exploratory drilling. Since no impacts 

 were identified, this five-year data base is considered an appropriate 

 benchmark for future drilling operations. 



Routine monitoring across habitat types from surface vessels appears to 

 be a waste of time. Examination of the benchmark data on annual variation in 

 species abundance, specifically for 14 designated key "indicator species," 

 suggests that no one species is likely to reflect anything but a major impact 

 from production drilling. We suggest that community composition be examined 

 in a "site-specific" manner, that is, by habitat type and specific location, 

 in order to define faunal benchmarks for future oil and gas exploration. 



