CHAPTER 1: EXECUTIVE SUMMARY 



The contents of this report result from a number of unusual cir- 

 cumstances, which provided a truly unique opportunity for the scientific 

 investigation of a medium-sized oil spill in a marine environment. 

 Although the disaster of a tanker grounding can hardly be called fortunate, 

 its location, circumstances, and timing were fortuitous. The sections 

 that follow will describe the unusual opportunity provided by the unfor- 

 tunate grounding of the Tsesis , and will discuss in general some impor- 

 tant lessons for the management of oil spills. 



1.1 Development, Early History and Cleanup of the Spill 

 (Olle Linden and John Kineman) 



At 11:05 a.m. on October 26, 1977, the Tsesis ran aground while 

 entering the Sodertalje ship channel in the archipelago about 50 km 

 south of Stockholm, Sweden. The position of the grounding was approxi- 

 mately latitude 58° 49.7'N and longitude 17° 43.8'E (Fig. 1.1). The 

 location is shown on the general chart of the area (Fig. 1.2) and on the 

 detailed chart of the ship channel (Figs. 1.3). 



The 19,334 dwt., 165-m long tanker, Tsesis , was owned by a Soviet 

 government shipping company in Ventspils, Latvia, and was enroute from 

 Ventspils with 17,575 tons of a medium grade fuel oil. The ship had 

 unloaded part of the cargo at Stockholm and was bound for the industrial 

 city of Sodertalje with a pilot when she struck the Karingklabben shoal, 

 immediately southeast of Fifong Island, in the southern part of the ship 

 channel. The submerged rock which the Tsesis struck was uncharted at 

 6.5 m depth, whereas the draft of the ship before grounding was estimated 

 to be about 8.5 m. 



On grounding, the ship was badly damaged and seven cargo tanks were 

 ripped open (Figure 1.4). The punctured tanks contained a total of 6400 

 tons of a straight run #5 fuel oil. This oil had a density of 0.9022 at 

 20 C and was derived from Russian crude oil. It apparently contained 

 enough of the original light crude fractions to allow it to emulsify. 



