hydrocarbons in common with a water-accommodated gasoline 

 standard. 



Twenty-three samples of flesh from 10 fish species collected in 

 the area of the Ocean 250 spill were analyzed for gasoline hydrocar- 

 bons. Five samples had levels ranging from 1 .6 to 2.4 ppm or twice 

 that found in the control sample (0.7 ppm). However, all samples 

 contained some HMW petroleum hydrocarbons; although not 

 quantified, several samples had levels of HMW two orders of 

 magnitude higher than the gasoline concentrations observed. 



Despite the volatile nature of gasoline, the water movement 

 due to tides and winds, the consequent redistribution of 

 zooplankton, and the probable movement of fish in and out of the 

 area immediately adjacent to the spill, results of analyses on water, 

 plankton, fish, and the immobile benthic invertebrates show the 

 presence of detectable levels of gasoline components. This indicates 

 a distribution of the gasoline at least for a short time throughout the 

 water column. The low levels found in the shellfish and plankton 

 could reflect a short period of exposure and the possibility of rapid 

 depuration. 



The presence of HMW hydrocarbons in many of the fish 

 samples is indicative of a chronic release of petrogenic hydrocar- 

 bons into the coastal and marine waters. The impact of this release 

 on fish populations and human health is not known at this time. 



3.G BIOLOGICAL ANALYSES 



3.1 Introduction 



The impact of oil spills on nearshore marine habitats and 

 renewable resources has been increasingly well documented over the 

 past decade. Much of this information was summarized in the 

 Oil/Environment- 1977 Symposium, and since then the impacts of 

 the Amoco Cadiz and Campeche spills have been reported. 

 However, these spills and subsequent studies have been of crude or 

 light oil products; there had been no significant gasoline spill in the 

 northeastern United States from which to draw inferences or com- 

 parisons of impact on marine communities at the time of the Ocean 

 250 spill. However, in the following studies an attempt was made 

 to characterize the species composition and abundance of benthic 

 and zooplankton communities in the area of the spill and to deter- 

 mine if there was any detectable adverse impact by the gasoline on 

 these communities. Additionally fish eggs collected in neuston and 

 plankton nets were examined for cytogenetic damage, since similar 

 analyses of fish eggs collected from areas impacted by various 

 pollutants, including oil, showed increased incidences of abnormal 

 mitotic divisions, development arrest, abnormal patterns of cell dif- 

 ferentiation, and other early indicators of embryo death (Longwell 

 1977; Longwell and Hughes 1989, In press). 



3.2 Analysis of Benthic Macrofauna from the Area of 

 Ocean 250 Gasoline Spill 



This section was prepared by Sheldon D. Pratt. 



Methods. — Triplicate Shipek grab samples were taken at six 

 stations on a 0.8 km grid previously established by the NMFS (Fig. 

 3-1). Relatively shallow stations were chosen where dilution of 

 gasoline components through vertical mixing would be minimized. 



The Shipek grab samples an area 0.04 m 2 and a maximum 

 depth of around 10 cm. Penetration was poor in fine compact 

 sands and samples with a depth of as little as 2 cm were retained for 

 analysis. 



Samples were preserved in rose-bengal formaldehyde and siev- 

 ed to 0.5 mm. For six samples the sediment passing the sieve was 

 saved and combined with residue from faunal sorting for grain size 

 analyses. Dried samples were sieved through a series of 10 screens 

 (2.0- < 0.074 mm) on a ro-tap machine and size fractions weighed. 



Fauna were identified to species in most cases. Indicators of 

 recent death or of morbidity were looked for as the fauna was 

 counted. 



Results and discussion. 



Physical environment. —Station locations and water depths 

 are shown in Figure 3 - 1 and Table 3 - 1 . The visual appearance of 

 the sediments and grain size distributions are given in Table 3-1 

 and Figure 3-2. 



All of the sediments indicated the dynamic nature of the 

 seafloor in the spill area. Sediment at station 7, in a passage between 

 rock reefs, consisted of rounded, rust-stained gravel and coarse 

 sand washed free of fine sediments by both wave and tidal currents. 

 Sediments at station 17 were a very well sorted fine sand stained a 

 dark rusty brown. This is probably the end product of vigorous 

 and continuous sorting of lower beach material in an oxidizing en- 

 vironment. 



The remaining samples were fine sand with gravel and silt. 

 High concentrations of blue mussel shell particles gave these 

 sediments a light gray color. Disaggregating fibrous shell material 

 clouded the water during sieving. The sediments from which blue 

 mussels were recovered consisted of medium sand and a fine sand 

 and silt fraction. Samples 5-1, 5-2, and 7-2 were too silty for sieve 

 analysis. It can be assumed that the fine sediment fraction is a result 

 of the trapping action and biodeposition of the mussel colonies. 

 These fine sediments are probably at least partially swept away by 

 winter storms. 



Mussels. — Clusters of the blue mussel were collected in 

 samples 5-1, 5-2, 5-3, and 7-2. The mussels were attached to each 



Tabte 3-1.— Shipek grab sample descriptions (Ocean 2S0 spin). One sample from 

 each station was analyzed for grain size. Sample 8-2 was not preserved property' and 

 was discarded. Stations depicted in Fignre 3-1. 



' 'Graduate School of Oceanography, University of Rhode Island, Kingston, 

 RI 02881. 







Sample 



Grain 





Station 



Depth 



volume 



size mode 





sample 



(m) 



(liter) 



(mm) 



Visual description 



2-1 



34 



0.75 



0.177 



gray shelly silty fine sand 



2-2 





1.0 



— 



gray shelly silty fine sand 



2-3 





0.75 



— 



gray shelly silty fine sand 



5-1 



9 



3.0 



— 



silty sand with live mussels 



5-2 





2.0 



— 



silty sand with live mussels 



5-3 





0.75 



0.5 



sand with live mussels 



6-1 



8 



0.8 



— 



gray shelly fine sand 



6-2 





0.8 



— 



gray shelly fine sand 



6-3 





0.75 



0.177 



gray shelly fine sand 



7-1 



9 



1.0 



— 



rounded gravel 



7-2 





0.75 



— 



silt, sand, gravel with mussels 



7-3 





2.0 



1.0 



coarse sand, gravel 



8-1 



23 



1.3 



— 



sand, gravel 



8-3 





1.8 



0.25 



sand, gravel 



17-1 



12 



1.3 



— 



brown fine sand 



17-2 





0.9 



— 



brown fine sand 



17-3 





0.75 



0.177 



brown fine sand 



16 



