About 1,100 metric tons of oil were spilled in the region and about 

 700 tons were recovered during cleanup operations. The oil was driven 

 by the prevailing winds to the northeast and, as a largely unweathered 

 oil slick, impacted the coastline at stations D, B, C, and F. Here the 

 littoral zone was severely impacted from a community standpoint (section 

 7). Concentrations of petroleum hydrocarbons in tissues were as high as 

 20,000 to 50,000 (Jg/g an d at this level mortalities seem to have occur- 

 red (section 7.2). 



As the slick passed through the region, significant quantities of 

 petrogenic hydrocarbons were mixed into the water column and concentra- 

 tions in the water as high as 50 \\g/ S. (greater than 100 times the back- 

 ground levels) were observed (Boehm and Fiest, 1978). In addition, oil 

 dispersed in the water column was sedimented to the bottom presumably 

 through (1) adsorption to detrital material and sinking and/or (2) 

 ingestion of oil droplets by zooplankters followed by fecal pellet 

 transport to the benthos. Visual scrutiny of zooplankters obtained 

 during the early stages of the spill demonstrated that oil had been in- 

 gested by zooplankters in the water column (see section 4.3.4). 



Oil remaining at the water's surface apparently underwent only slow 

 degradation due to chemical and microbial weathering until landfall 

 occurred. However, petroleum material dispersed in the water column 

 underwent rapid bacterial degradation of the aliphatic hydrocarbons with 

 n-alkanes being rapidly depleted relative to the isoprenoid compounds 

 and rapid removal of the lighter aromatic fraction due to dissolution. 

 Measurements of the bacterial populations following the spill indicate 

 an increase in the bacterial population in the water column possibly due 

 in part to the availability of oil as a carbon source (see section 

 4.3.3). Those stations receiving secondary impacts of the spilled oil 

 (i.e., those receiving a secondary landfall of oil), most notably sta- 

 tion G (at first this was designated as a control station due to no 

 obvious landfall of the spilled oil), received a degraded oil as seen in 

 the Mytilus tissues due to the longer residence of this petroleum mater- 

 ial in the water. 



269 



