. Table 9 



Concentrations of Different Petroleum Hydrocarbons in the Tissues of Oysters Crassostrea 



virginica after S hours Exposure to a #2 Fuel Oil-In-Water Dispersion and at 



Different Times Following Return to Oil-Free Sea Water 



* n-P, n-paraffins; N. naphthalene; l-MN, 2-MN, 1 methyl- and 2-methlynaphthalenes; 

 DMN, dimethylnaphthalene; TMN, trimethylnaphthalene; B, biphenyl, MB, methylbiphenyl; 

 F, fluorene, MF, methylfluorene; DBT, dibenzothiophene; P, phenanthrene; MP, methylphenan- 

 threne; DMP. dimethylphenanthrene. 



sitive fish have gill surfaces more permeable to hydrocarbons and that 

 hydrocarbon accumulation in the brain and heart result in respiratory 

 depression or narcosis. When surviving fish were returned to oil-free 

 sea water, they recovered rapidly. The high concentrations of naph- 

 thalenes in the gall bladder indicate that the liver-gall bladder system 

 is an important avenue of naphthalene excretion in fish. Although 

 hydrocarbon accumulation appears to occur primarily across the gill 

 surfaces, feeding experiments have shown that substantial uptake can 

 also occur through the digestive tract. The gut may represent an im- 

 portant uptake route in those marine fish which actively drink sea 

 water. 



Similar studies with brown shrimp Penaeus aztecus indicate that 

 the majority of accumulated naphthalenes is associated with the diges- 

 tive gland soon after exposure begins and this organ retains the com- 

 pounds for the longest period following exposure. When shrimp are 

 returned to oil-free sea water, the tissues other than the digestive gland 

 released the accumulated naphthalenes rapidly and the edible muscu- 

 lar abdomen is one of the first body regions to depurate to background 

 levels. It may be that the relatively rapid release of naphthalenes by 

 fish and crustaceans is partially due to active detoxification and excre- 

 tion mechanisms. The slower release rates exhibited by bivalves 



29 



