by ARCO's Spark platform. Union platform Monopod, and Texaco-Superior 

 platform A. Further south is the MacArthur River field operated by 

 ARCO's platform King Salmon, Marathon Oil Company's Dolly Varden 

 platform, and Union's platform Grayling. The southernmost field is the 

 Middle Ground Shoal where AMOCO's platforms Baker, and Dillon and Shell 

 Oil Company's platforms A and C are operating. Phillip's Petroleum 

 operates platform Tyonek, the northernmost platform in the Cook Inlet, 

 which produces only natural gas. 



Since all the platforms are grouped close to each other, much of 

 the reported marine mammal activity is the same. The few reports of 

 mammals other than beluga whales were from the same or neighboring 

 platforms. 



It is clear that beluga whales are seen throughout the inlet. 

 Their behavior does not seem to be affected by the presence of the 

 platforms; their movement seems to be affected mostly by the tides and 

 movements of the fish they are after. Many reports state that belugas 

 were seen almost underneath the platforms. (Generally, when looking 

 straight down and seeing an animal, the distance of the animal from the 

 platform legs would be about 30 feet.) These whales are seen in the 

 greatest number at slack tide, when movement within the area is the 

 easiest. 



The few reports of other animals are well substantiated. The 

 novelty of seeing killer whales or sea lions was not blocked by the 

 commonness of seeing beluga whales. One walrus was spotted and 

 reported to Fish and Game, whose agent said that the walrus was 

 "probably lost." 



Due to the constant siltiness of the water it is difficult to 

 locate animals, except the white whale which shows up \/ery well against 

 the murky water. This heavy silt could also discourage most other 

 species from entering and inhabiting the inlet; only the belugas seem 

 to adapt well to the poor visibility and tides. The general consensus 

 seemed to be that the beluga whale population probably has increased 

 considerably over the last 5 years. 



The oil companys ' record regarding oil spills in the Cook Inlet is 

 very good. No major spills and wery few minor ones have occurred. No 

 natural areas of seepage are prominent, and with the tidal flow so 

 strong, oil would dissipate almost totally before reaching shore. 

 Nevertheless, the clean-up crews practice a couple of times a month and 

 everyone is very aware of "cleanliness." The waste water discharged 

 into the Cook Inlet from the platforms is filtered to the point that it 

 is cleaner than when it was taken out. 



The underwater environment of the Alaska platforms does not support 

 as diverse flora and fauna as their Santa Barbara Channel counterparts. 

 This could be due to the swift currents or to the high silt content in 

 the water or to the cathodic protection system of the Alaska platforms. 



C-26 



