Oil can be ingested as animals try to clean themselves. 

 Bird mortality, as a result of direct oil coating, has been 

 well-documented along the California coast. 



The fourth response is the incorporation of hydro- 

 carbons in food chains. This includes tainting of edible 

 organisms , such as oysters and clams. Accumulation and 

 concentration of polycyclic aromatic hydrocarbons are 

 major concerns especially since this includes carcinogens. 



The final response listed is changes in biological 

 habitats, especially alteration of substrate characteristics. 

 The substrate is the ocean floor material that supports 

 plant or animal life. Species living passively on the 

 substrate (not depending heavily on the substrate for 

 support) may have little or no interference with their 

 habitat. Flora and fauna living in the substrate or actively 

 dependent on it may experience adverse effects (Council on 

 Environmental Quality, 1974: 106). Although the quantity and 

 types of oil that may prevent a species from utilizing a sub- 

 strate are unknown, analysis of data indicates concentrations 

 of 10 to 100 parts per billion (ppb) of low to medium boiling 

 point aromatic hydrocarbons may interfere with the species' 

 relationship to the substrate. Chemical sensing and communi- 

 cations upon which anadromous fishes depend will be interfered 

 with by the presence of aromatic hydrocarbon derivatives 

 in such concentrations (Council on Environmental Quality, 

 1974: 106-107). 



96 



