UPTAKE, DISTRIBUTION, AND DEPURATION OF ^^C-BENZENE 



IN NORTHERN ANCHOVY, ENGRAULIS MORDAX, AND 



STRIPED BASS, MORONE SAXATILIS 



Sid Korn,' Nina Hirsch,^ and Jeannette W. Struhsaker^ 



ABSTRACT 



The uptake, distribution, and depuration of water-soluble, monocyclic hydrocarbon contained in 

 petroleum and refined products was studied in two species of marine fish. Mature northern anchovy, 

 Engraulis mordax, and juvenile striped bass, Morone saxatilis, were exposed to sublethal concentra- 

 tions of '^C-benzene for 48 h. Residues in tissues exhibiting a high lipid content or representing 

 apparent major metabolic sites were measured during the exposure and afterwards when the fish were 

 transferred to clean seawater. Fish exhibited a rapid uptake over a wide range of benzene 

 concentrations in the water column. Accumulation in anchovy was considerably greater than in striped 

 bass. Results indicate that the pathway of hydrocarbons through the liver, gallbladder, intestines, and 

 colon is a major depuration route. Residues were depurated rapidly after cessation of exposure; in 

 striped bass tissues most residues were undetectable by 7 days. 



Increased drilling, transportation, and refining of 

 crude oils near or on coastal waters has led to the 

 need for research on the effects of oil on estuarine 

 biota. Considerable public concern has evolved 

 from such occurrences as tanker spills and the 

 Santa Barbara well blowout. However, long-term 

 sublethal effects of low levels of oil in inshore areas 

 may be of greater importance to marine popula- 

 tions than short-term lethal effects of high levels 

 resulting from catastrophic events such as tanker 

 spills and drilling blowouts. It is important to 

 study the effects of chronic oil exposure on marine 

 organisms. 



Benzene is a principal aromatic oil component 

 (up to 6.75 ppm in the water-soluble extract 

 [Anderson et al. 1974]) that is relatively water 

 soluble (1,993 jul/liter [Benville and Korn 1974]) 

 and has significant effects on fishes (Brocksen and 

 Bailey 1973; Korn et al. in press). The preceding 

 studies demonstrated the effects of benzene on the 

 nervous system, respiration, and growth of fish. 

 Brocksen and Bailey showed latent effects of ben- 

 zene on respiratory response lasting up to 6 days 

 after fish were placed in clean water. 



Concentrations of highly volatile monocyclic 

 aromatics such as benzene are not thought to be 

 very high in areas subject to chronic exposure to 



^Southwest Fisheries Center Tiburon Laboratory, National 

 Marine Fisheries Service, NOAA, Tiburon, Calif.; present 

 address: Northwest Fisheries Center Auke Bay Fisheries 

 Laboratory, NMFS, NOAA, P.O. Box 155, Auke Bay, AK 99821. 



^Southwest Fisheries Center Tiburon Laboratory, NMFS, 

 NOAA, 3150 Paradise Drive, Tiburon, CA 94920. 



oil. However, measurements of monocyclic 

 aromatics in such situations are scarce. Our 

 preliminary measurements in San Francisco Bay 

 indicate a maximum range from 1 to 10 jul/liter 

 benzene in relatively unpolluted bay areas. Al- 

 though the chronic levels are low, if fish ac- 

 cumulate benzene over field concentrations and if 

 energy is required to metabolize, detoxify, and 

 depurate accumulated aromatics, detrimental 

 long-term physiological effects are possible. 



Investigators such as Lee, Sauerheber, and 

 Benson (1972); Lee, Sauerheber, and Dobbs (1972); 

 Anderson et al. (1974); and Lee (1975) examined 

 uptake of higher aromatics in invertebrates and 

 fish, but no work has been done with benzene. 



The fish we studied were San Francisco Bay 

 species but also occur widely in other areas where 

 chronic oil pollution may pose a problem. Striped 

 bass, Morone saxatilis, is an important recrea- 

 tional species on the west and east coasts, while 

 northern anchovy, Engraulis mordax, is not only a 

 major forage fish for striped bass but also consti- 

 tutes the greatest biomass of any fishery in the 

 California Current. 



The objective of this study was to determine the 

 uptake, distribution, and depuration of benzene in 

 these two species of fishes. 



METHODS 



Adult northern anchovies were obtained from a 

 local bait dealer and acclimated under controlled 



Manuscript accepted March 1976. 

 FISHERY BULLETIN: VOL. 74, NO. 3, 1976. 



545 



