PRACTICAL, ENVIRONMENTAL AND STRATEGICAL EXPERIENCES FROM TWO SPILLS IN 2011 OF CRUDE OIL AND CTO ALONG THE SWEDISH COASTLINE

Abstract

ABSTRACT In 2011, the Swedish coastline suffered two major oil spills. About 500 tonnes of bunker oil occurred in the marine waters of the west coast, in the waters of Skagerrak, on to the coastline of the Tjörn archipelago. The second spill, about 800 tonnes of CTO (crude tall oil) occurred from a land based tank farm on the east coast, into the Söderhamn archipelago in the brackish Baltic Sea. Both impacted areas exhibit a high ecological value and are frequently used for outdoor recreation. In Söderhamn, many private properties were impacted as opposed to Tjörn, where the archipelago is common land. The affected coastal area at Tjörn comprise rocky beaches with varying degrees of cracks, bays, rock pools, etc. At Tjörn, remediation has been made through manual labor combined with experimental methods facilitating faster manual removal; such as mineral oil degreasers, coconut oil, rapeseed oil, and heating up the oil by means of a torch. Manual labor through scraping with various tools (e.g. spatulas, knives, cloths) has however been the main method. The remediation was difficult and dangerous due to the slippery rocks and tough weather conditions. The shores of the Söderhamn Bay consist mainly of rocky beaches, large rocks as well as very small pebble stones. Since the oil also got into jetties, the entire clean-up process has been difficult and time consuming, also due to the cold weather conditions in the north. Remediation of the shores and stone coffins, inside the jetties, has been made through manual labor. The impacts to the bird population were minimal in both incidents since most birds had migrated for the winter. At Tjörn, some short-term impact could be noted on indicator species like the Blue mussel. The incident happened during late fall, when the biological activity in marine organisms is low; hence low impact on the marine organism's active reproductive periods. In Söderhamn, fatty acids, recin acids and sterols have been sampled in sediments, fish muscle, and mussels. Limited impact could be noted, however, established test methods are missing for CTO. Degradation time of the CTO was longer than expected. Extensive and hardcore cleanup usually causes more damage to nature; removal of important microorganisms, increased soil erosion and diminishes the possibilities for the vegetation recovery. It is cucial to start the communication process with public and property owners as early as possible to set expectations on how clean is clean.