down very slowly and may persist for a considerable period, increasing the 

 opportunity for uptake by the plants. Our observations suggest that if con- 

 tamination by heavier oils affects only a portion of the aerial root system, 

 plant recovery is probable. Exposure to light fuel oil can be expected to 

 have serious effects, although plants may recover from low levels of contamination, 



RESTORATION TECHNIQUES 



No proven techniques have been identified. Based on real world observa- 

 tions, however, possible beneficial actions may be suggested. Mangroves 

 routinely collect seagrasses along their fringes among their aerial roots. 

 When sufficiently concentrated, these accumulations have been observed to 

 prevent oiling of the root systems. The concentrations should be particularly 

 effective at minimizing the impacts of light oils. Since oil and seaweed 

 debris will ultimately be incorporated in the substrate, recovery of these 

 materials will be necessary. Recovery should be carefully controlled to 

 prevent mixing with the uncontaminated substrate. The effectiveness of the 

 natural seaweed debris barriers suggests the possible application of straw 

 or other degradable material as a protection/restoration measure. 



Once contamination of root systems has occurred, restoration should proceed 

 as rapidly as possible, with particular care being taken to minimize physical 

 damage to the plants. Water flushing using portable, boat-mounted pumps is 

 generally effective in removing the bulk of both light and heavy oils. Water 

 flushing offers the additional advantages of limiting operations in the man- 

 grove forest. 



Use of granular-type sorbents may aid in reducing substrate penetration. 

 Generally, however, these materials do not remove the oil, and only cause 

 additional cleanup problems. Pad-type sorbents have been used manually to 

 wipe aerial roots. Such action most likely results in additional pore clogging, 

 and thus extension of damage, and is not recommended. 



CONCLUSIONS 



With the possible exception of the use of heavy equipment for sandy beach 

 cleaning, a definitive and effective state-of-the-art for restoration of oil- 

 contaminated shorelines is nonexistent. However, common sense applications 

 of the knowledge and resources that are presently available can provide accept- 

 able interim actions. Each restoration situation has its own peculiarities 

 and requirements. If several basic assumptions are adhered to, the best 

 practical restoration decisions should result. These assumptions include: 



• Any activity will have some effect on the environment. The 

 restoration procedure and supporting activities (i.e., access, 

 disposal, etc.) must not result in more environmental damage 

 than that caused by the oil itself. 



• The restoration procedure should remove (or move to a position 

 where recovery is possible) a maximum amount of contaminant 

 with a minimum amount of disturbance, modification, or removal 

 of the habitat. 



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