Figure 41. Pathways of oil incorporation into marine ecosystems and 

 effects on marine life (Source: Reference 128). 



COATING 



A DIRECT KILL 



B REDUCE RESISTANCE TO 

 OTHER ENVIRONMENTAL 

 STRESSES eg TEMPERATURE. 

 DISEASES. OTHER POLLUTANTS 



OIL INGESTED OR INCORPORATED 

 ACROSS MEMBRANES eg GILL 

 SURFACES 



A DIRECT KILL 



B SUBLETHAL EFFECTS 



1 REPRODUCTIVE FAILURE 



2 CHEMICAL COMMUNICATIONS 

 FAILURE 



3 STRESSED AT DISADVANTAGE 

 TOOTHERSPECIESog 

 ABILITY TO AVOID PREDATOR 

 AND TO CAPTURE PREY 



4 DISRUPTION OF MIGRATION 

 eg SALMON 



EFFECTS ON MARKETING OF 

 COMMERCIALLY VALUABLE SPECIES 



1 TAINTING ASTHETICALLY UNPLEASANT 

 2- HUMAN HEALTH HAZARD - POTENTIAL 

 HAZARD LITTLE KNOWLEDGE 



The potential threat of carcinogenic petroleum substances transmitted 

 into the human food chain from contaminated seafood products remains to be 

 scientifically demonstrated. The rates of transfer and long-range fate 

 and effect of water soluble components of petroleum are also poorly 

 understood. 



Heavy metals : Heavy metals discharged by OCS-related facilities 

 include beryllium, cadmium, chromium, copper, lead, mercury, nickel, 

 silver, vanadium, and zinc [7]. Their salts are relatively soluble and 

 stable in solution; consequently, they will persist for extended lengths of 

 time. The presence of these metals from industrial waste discharge, even in 

 small concentrations, can have deleterious effects [84], primarily because 

 of biomagnification. 



In order of generally decreasing lethality to aquatic organisms, 

 mercury, silver, and copper are at the top of the list, followed by cadmium, 

 lead, chromium, nickel and cobalt [129]. Although the sediments can 

 sometimes act as a sink for entrapment of metals, activities such as 

 dredging often release metals back into the marine ecosystem, potentially 

 contaminating fisheries' resources and possibly entering the human food 

 chain. 



Biochemical Oxygen Demand (BOD): One of the major constituents of 

 industrial wastes related to hydrocarbon processing is decomposable organic 



162 



