The peculiar growth of Fucus observed at station B was probably an 

 effect of the low water which exposed the Fucus tips to the air, causing 

 the protective mucilage layer to dry out . This layer may prevent the 

 Fucus plants from being damaged by contamination. The Fucus plants is 

 rather resistant to light and heavy fuel oil exposure, as shown in 

 outdoor laboratory tests (Ganning and Billing, 1974; Notini, 1978). 



Results from station B indicate a doubling of the Fucus biomass. 

 This can probably be explained by the heterogeneity of the Fucus belt at 

 that station. A very small change in the sampling site could change the 

 results drastically. It is expected that the Fucus belt would not 

 increase as much as the results indicate. The increase of Fucus biomass 

 (40%) at station D ( Fucus belt) might be explained in the same way. 



The increase of animal biomass in the Fucus belt at station B in 

 June was caused mainly by increased numbers of Mytilus . These may be 

 the same individuals which were removed and transported from the shal- 

 lower situated Cladophora belt due to narcosis from oil contamination or 

 through mechanical stress during the cleanup operations on the shore. 

 It could also be due to the larger Fucus biomass sampled. 



Some crustaceans, which have a hydrophobic wax layer on their 

 cuticle, are very sensitive to oil contact (Notini and Hagstrom, 1974). 

 This may explain the drastic decrease of the crustaceans (vagile forms) 

 at the oil-contaminated stations in November. 



The rapid recruitment of vagile forms from adjacent areas in the 

 Baltic has also been observed by Pelkonen and Tulkki (1972) and Notini 

 (1978). This is also indicated by the high proportion of young in- 

 dividuals at the contaminated station. 



The lack of chironomid larvae at station B (Table 7.3.3) may be an 

 effect from the oil spill as these organisms have proved to be sensitive 

 to oil contamination (Bengtsson and Berggren, 1972). However, the 

 sampling was too small to allow any definite conclusions. 



The results of the oil analysis from the reference station G are 

 confusing. The high oil content in Mytilus is not correlated with 

 absence of vagile forms as at the visibly contaminated stations. 



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