8.1.3 Results: Acute effects on vegetation 



In general the plants seemed to be astonishingly little affected by 

 growing on or in close contact with heaps of oil on the shores. This 

 impression is characteristic of all the areas and different types of oil 

 studied. At places with a dense layer of oil, however, the plants 

 showed frequent signs of abnormality or injury. It is, of course, 

 impossible in any one instance to distinguish with certainty between 

 effects caused by oil or, for example, by parasites or local variation 

 in water supply. However, the following observations have been made 

 several times and are, with fair reliability, oil-dependent. 



Filipendual ulmaria and Lysimachia vulgaris were very dwarfish when 

 growing on soil heavily impregnated with oil. Seedlings of these grow- 

 ing through a thick layer of oil also showed strong malformations. 

 Deformities were also observed in Valriana officinalis and Tussilago 

 farfara . Discoloration, reminiscent of water shortage, was noted in 

 Festuca rubra , Agrostis stolonifera , Atriplix latifolia and Equisetum 

 arvense when the plants were on or close to oil on the shore. Some 

 specimens seemed less sensitive and Cirsium arvense was found on several 

 occasions growing on thick heaps of oil without visible effects. 



8.1.4 Some comments on the clean-up methods 



In the Torb'-Svardso area there are several different types of 

 shore. Rocks, stone, gravel and sand, in places exposed to wave action, 

 and fine-grain sediment shores with reeds in more sheltered bays. 



Rock dominated areas: The only vegetation are lichens and micro- 

 scopic algae. No attempts were made to estimate how these were affected 

 by oil. On these kinds of shores the oil, which soils the rocks with a 

 more or less thick covering, is removed by spraying with water at high 

 pressure, scrubbing with oil-dissolving chemicals or steam treatment, 

 which makes the oil easy-flowing." All methods, however, only transfer 

 the oil to the water. It is hardly possible to take care of and destroy 

 all the oil on these shores and, instead take all possible measures to 

 prevent the oil from reaching them. 



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