Chapter Four Effects of Cleanup Techniques

Various measures are taken to lessen the visual and ecological impact of spilled oil. At least for most larger spills these measures have proved relatively ineffectual and in some cases have worsened the biological impact of an oil spill. Techniques have variously involved containment by barriers and physical removal of floating oil, the use of absorbent material to concentrate oil, sinking, burning, chemical dispersal, and steam cleaning of oiled shores ().

Containment and removal are most desirable from the viewpoint of avoiding biological damage, because oil is removed from the environment without the addition of any foreign substance. Unfortunately, the floating booms and skimmers used are only efficient in calm water, and the technology developed to this point has not proved successful in severe weather. Another drawback of these and other techniques involving physical removal is that, to be effective, they must be applied immediately after the accident. The use of absorbents has been in favor in North America. Straw was used with some success following the Santa Barbara and San Francisco spills, both on floating and stranded oil. The ecological impact of the straw appears slight; however, dried oil and straw deposits in the intertidal appear to be more persistent than those of oil alone (). Peat moss was used effectively to cleanse shores oiled by the Arrow in Chedabucto Bay. The use of synthetic absorbents (oleophilic plastic polymers) seems to be increasing, thus posing the problem of the persistence of the non-biodegradable absorbent material escaping recovery.

The sinking of oil with chalk or sand has often been recommended and used in Europe. However, from the biological viewpoint it appears to be among the least acceptable countermeasures. Sinking an oil slick may save the intertidal zone from pollution, but it deposits oil over a large area of the bottom, where it may persist in the sediments. In coastal and estuarine environments, it is the productive benthic life that supports most of the finfisheries as well as shellfisheries.