harvesting seemed completely normal and on re-visiting it was not always 

 easy to distinguish oil affected and non-affected sites. Even the 

 smaller species seemed to have recovered - for instance Myosotis palustuis 

 and (.at Varmdo) the tiny annual Montia fontana . Thus clean-up operations 

 on these shores seem to have worked very well. The oil was taken away 

 from the area to be destroyed instead of being washed back into the sea 

 and the cleaned areas seemed to recover fairly soon. 



8.1.5 Concluding remarks 



No very significant oil-induced vegetation damage could be demon- 

 strated in this study. One cannot however eliminate the possibility 

 that some effects will show only after a considerable period has 

 elapsed. What will happen to the oil that has been left in the soil 

 despite the cleanup? How is it broken down and into what substances? 

 Are any of these more toxic than the oil itself? Are some substances so 

 slowly accumulated by roots and rhizomes that injuries will not show 

 until much later? These and other important questions can only be 

 answered by further studies including experimental field work. 



Cleaning operations must aim towards removal and destruction of the 

 oil. Pollution of rocky and stony shores must for this reason be mini- 

 mized by channeling the oil towards sheltered bays at an early stage 

 when this is at all possible. This will also prove to be economically 

 beneficial since cleaning of rocks and stones is very time consuming. 

 Absorption of the oil using bark splinters and sowing of grass, which 

 have been tried in some places, seem very doubtful methods from a bio- 

 logical point of view since the oil will remain with unknown conse- 

 quences. The results will at best give rise to unnatural systems with 

 species poorly adapted to the gradients of shore salinity. 



172 



