WINKLER ET AL.: EFFECTS OF BENZO(A)PYRENE ON CALIFORNIA GRUNION 



BaP, can alter the duration and time of teleost hatch- 

 ing (Ernst et al. 1977; Leung and Bulkley 1979; Han- 

 nah et al. 1982). Normally, hatching of California 

 grunion eggs occurs in 10-14 d. Since most hatched 

 eggs in this study did so on day 10 and no later than 

 day 13, no effect was noted on duration and time of 

 hatching of California grunion eggs. The dramatic 

 and significant effect was on hatching rate. 



The second effect noted was increased abnor- 

 malities of the developing yolk-sac larvae embryos. 

 Of those yolk-sac larvae observed, 20% had a mid- 

 body lateral curvature when exposed to 24 ppb BaP 

 or greater, as compared with 9 '/i of the controls. Vas- 

 cular abnormalities observed in embryos included 

 stasis in yolk-sac vessels, apparent hemorrhages in 

 the caudal regions, intermittant heart beat, and dis- 

 tinctly underdeveloped bodies with nonutilized yolk 

 hydrocarbons (Ernst etal. 1977; Lonning 1977), par- 

 ticularly BaP (Hose et al. 1981, 1982; Hannah et al. 

 1982). Depressed heart rates of fish embryos treated 

 with high levels of petroleum hydrocarbons have 

 been attributed to inhibition of metabolism and/or 

 neurotransmission (Whipple et al. 1981) and can 

 result in partial or complete mortality (Anderson et 

 al. 1977). 



The third response observed in California grunion 

 embryos exposed to BaP was reduction in notochord 

 length. The notochord length of embryos exposed to 

 24 ppb BaP averaged 107c of that of controls. At 297 

 ppb BaP or greater, the notochord length of affected 

 embryos was generally <50% of the notochord 

 length of the control group. Retarded growth was also 

 evident in rainbow trout alevins reared in 0.08-2.99 

 ppb BaP (Hannah et al. 1982) and may result from 

 the inhibitory effects of polycyclic aromatic hydro- 

 carbons on DNA synthesis (Santodonato et al. 1981) 

 and, hence, mitosis (Bourne and Jones 1973; Kocan 

 etal. 1981). 



At the end of 14 d, embryos exposed to initial con- 

 centrations of 24-297 ppb BaP resembled normal 

 embryos at 2.5-5.5 d of development. This retarded 

 growth was characterized by a lack of lens formation, 

 absence of caudal fin folds, and a reduced number of 

 melanophores. However, there was one exception to 

 this trend of slow development: The pectoral fins of 

 embryos treated with 24-297 ppb BaP appeared to 

 be of normal size and maturity, whereas all other as- 

 pects of embryo development seemed severely 

 delayed. Irregular cleavage and retarded develop- 

 ment in oil-treated fish embryos have been previous- 

 ly described (Lonning 1977), and assessment of the 

 developmental effects of petroleum hydrocarbons on 

 marine fish eggs has been reviewed by Kuhnhold 

 (1977). These include sublethal effects such as 



chromosomal aberrations and morphological 

 anomalies as well as direct toxicity (Rosenthal and 

 Alderdice 1976). Toxic hydrocarbon levels reported- 

 ly correlated with mitotic errors in eggs of Atlantic 

 mackerel, Scomber scombrus, (Longwell and Hughes 

 1980). Anderson et al. (1977) also noted lack of 

 pigmentation in estuarine killifish, and a histological 

 examination of Fundulus grandis embryos exposed 

 to the water-soluble fraction of No. 2 fuel oil revealed 

 pathological lens, liver, kidney, and epthelial tissues 

 (Ernst et al. 1977). 



In summary, the effects observed in California 

 grunion embryos exposed to the carcinogen BaP 

 were threefold: Decreased hatching rates, increased 

 number of morphological abnormalities, and short- 

 ened notochord lengths. These grossly visible 

 alterations would be detrimental to the potential 

 growth and survival of fish in the wild (Rosenthal and 

 Alderdice 1976). The number of fish reaching 

 adulthood would decrease directly as a result of the 

 lethal effects of BaP on embryos and indirectly as a 

 result of decreased ability of affected fish to elude 

 predators. Also, short-term observations such as 

 these do not address the problem of carcinogenesis, 

 although recent experiments have demonstrated 

 that the polycyclic aromatic hydrocarbon, 7,12- 

 dimethylbenz(a)anthracene, is tumorigenic in 

 freshwater fish (Schultz and Schultz 1982). 



It is predicted that BaP will increase in the environ- 

 ment unless restrictions can be imposed upon its pro- 

 duction. However, reduced production of BaP is 

 unlikely, as this compound is an unavoidable by- 

 product of incomplete combustion and petroleum 

 usage (National Academy of Sciences 1972). 

 Therefore, the results of our experiments indicate 

 that the short- and long-term effects of BaP on the 

 developmental stages of fish and other marine life 

 warrant further investigation. 



ACKNOWLEDGMENTS 



We thank Gilbert Jones, Basil Nafpaktitus, James 

 Kremer, Gary Brewer, and Steve Kottmeier for their 

 suggestions, and Bob Arthur, Melanie Posner, and 

 Havens Newman for technical assistance. 



LITERATURE CITED 



Andelman, J. B., AND M. J. Suess. 



1970. Polynuclear aromatic hydrocarbons in the water en- 

 vironment Bull. W.H.O. 43:479-508. 

 Anderson, J. W., D. B. Dixit, G. S. Ward, and R. S. Foster. 



1977. Effects of petroleum hydrocarbons on the rate of heart 

 beat and hatching success of estuarine fish embryos. In F. 

 J. Vernberg, A. Calabrese, F. P. Thurberg, and W. B. 



479 



