Sheltered Rocky Coasts 



Spilled oil tends to coat the rough surface of rocks within sheltered 

 environments. Because wave energy is low, oil may persist several months to 

 years. The resident biological community is usually abundant and diverse, 

 and very likely to be damaged or destroyed during an oil spill. 



Sheltered Estuarine Tidal Flats 



Several sheltered tidal flats in France remained severely contaminated 

 at least 8 months after the spill. Even in places where mechanical cleanup 

 operations succeeded in removing surface oil, the interstitial water was still 

 oiled. The latter condition may have a negative effect on recolonization. 



Sheltered Salt Marshes and Mangrove Coasts 



Salt marshes and mangroves are the most productive portion of the 

 coastal zone. It has been shown that large amounts of oil in the marsh envi- 

 ronment can be devastating, as at the Metula and Amoco Cadiz spill sites. At 

 West Falmouth, Massachusetts, the effects of the 650 ton Florida spill (No. 2 

 oil) were detectable for at least 7 years (Krebs and Burns 1977). With lesser 

 quantities, the marsh may be able to recover (e.g., Uvquiola site), although 

 repeated spill incidents are usually damaging (Baker 1971). 



There is evidence that heavy oiling of mangroves can be equally as dam- 

 aging. The most notable case occurred in southwest Puerto Rico where the 

 Zoe Colocotronis caused the defoliation and death of one hectare of red and 

 black mangroves (Nadeau and Berquist 1977). In another case (Florida Keys oil 

 spill), Chan (1976, 1977) reports that mangroves were killed where the sedi- 

 ment or pneumatophores were oiled. Recently, the defoliation of 1.9 hectares 

 (0.5 acres) has been documented by our research group at the site of the Peak 

 Slip oil spill in eastern Puerto Rico. Defoliation and probable death seemed 

 to occur where both sediment and prop roots were heavily oiled. Recovery of 

 a mangrove ecosystem takes an estimated 20 years (Odum and Johannes 1971). 



METHODS OF APPLYING THE VULNERABILITY INDEX 



The integrated zonal method is the primary technique of application. 

 This method has been adapted from the zonal method developed by Hayes, et al . 

 (1973) to classify large sections of the Alaskan Coast for the Office of Naval 

 Research. The addition of a biological component to these field studies pre- 

 sents an integrated approach to determining environmental protection prior- 

 ities. The index has been applied to Lower Cook Inlet under sponsorship of 

 the Alaska Department of Fish and Game and National Oceanic and Atmospheric 

 Administration (NOAA) (Hayes et al. 1976, Michel et al . 1978). Currently, 

 work is underway to apply this system to Prince William Sound at the entrance 

 to Port Valdez, Alaska and to Puget Sound, Washington. Both projects are 

 sponsored by NOAA. The method is briefly summarized as follows. 



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