of the two cargoes were reported to be nearly identical, it is hoped that 

 despite the lack of samples from the second, they may have differed only in 

 their relative proportions of "cutter stock." 



P. Fricke of Woods Hole Oceanographic Institution obtained 5 gallons of 

 "surrogate" Avgo Merahant oil on February 5, 1977, from a tanker in Boston 

 harbor. This "surrogate" oil was No. 6 fuel oil from the same refinery and 

 had undergone the same refining process as the oil carried by the Argo Mer- 

 chant. Samples have been made available to all cooperating investigators for 

 further studies. 



In addition to the surrogate sample, P. Fricke is trying to arrange for 

 samples of the two actual Argo Merchant oils to be shipped from the refinery 

 in Venezuela within a few months. Because of the apparent fractionation of 

 lighter components of the Argo Merchant oil into the water column, it will 

 also be necessary to obtain a reference sample of the "cutter stock," which 

 was used for improving the handling characteristics of the tanker's cargo, 

 before accurate oil-in-water concentrations can be reported. Fricke is 

 attempting to obtain such a sample also. 



3.2.1 Oil Slick Sampling and Analyses 



Samples 



Samples that have played a significant role in the analysis of the fate 

 of the Argo Merchant oil slick include: (1) surface samples taken by J. H. 

 Milgram on December 17 and 19, 1976, within 1 mile of the tanker, and (2) a 

 surface sample taken with a bucket lowered from a helicopter on December 19 

 near the "head" end of the horeseshoe-shaped slick. The first samples were 

 ^ about 2 hours hours old according to Milgram's estimate. The second sample was 



taken on December 19 by J. Gait and J. Mattson of NOAA at 41°04.0'N latitude, 

 69°18.2'W longitude, and was probably 2 to 3 days old. On December 23, S. 

 Fortier of the USCG Research and Development Center took three surface slick 

 samples from a helicopter. These samples are stored at the Center. On 

 December 25, the USCGC Vi-g-ilant obtained a sample from the large pancake of 

 oil sighted that day, and that was the last surface slick sample collected 

 from the oil spilled by the Argo Merchant. Part of the last sample is held, 

 by Milgram at MIT. 



Physical properties 



Analyses of the surface slick samples as well as of the sample taken 

 directly from the Argo Merchant were performed by Milgram and by J. Quinn of 

 the University of Rhode Island. The physical properties reported by Milgram 

 for the cargo sample and the "thick" surface slick sample he obtained on 

 December 19 are listed in Table 3-1. 



In addition, Milgram subjected the cargo sample to atmospheric distil- 

 lation, noting that 20% of the cargo sample distilled off at temperatures 

 below 210°C, undoubtedly representing the light distillate "cutter stock" 



t* 



70 



(but no precise estimate can be made^ Ed.) 



