the biofouling community for food. No significant trace metal 

 contamination related to BGOF operations was demonstrated (Tillery 

 1980) . 



Spadefish showed no evidence of either petroleum or trace metal 

 contamination attributable to BGOF operations, and were characterized by 

 the lowest levels of total alkanes of any fish tested (Middleditch and 

 West 1980; Tillery 1980). Density levels of spadefish were equivalent 

 among the various structure types in the field. Seasonal disease 

 epidemics were observed but seemed best explained by natural phenomena. 

 Whereas condition of spadefish was significantly lower during winter 

 than during other seasons as might have been expected, condition did not 

 differ significantly among the structures sampled during winter. 



However, the possibility, although considered to be slight, remains 

 that the winter disease epidemics may have been related to the chronic, 

 low-level discharge of contaminants. Minchew and Yarbrough (1977) found 

 that 96% of the mullet, Hugii cephalus , held in ponds subjected to a 

 low-level oil spill (4 to 5 ppm) suffered fin rot whereas only 6 % in a 

 control pond developed eroded fins. The primary pathogen considered 

 responsible for the fin erosion was a species of Vibrio . Subsequent 

 laboratory work by Gilles et al. (1978) confirmed the above results and 

 showed that chronic, low-level exposure of mullet to oil significantly 

 altered the bacteria on the fish, allowing for a large population of 

 potentially pathogenic Vibrio . They also suggested that the Vibrio , 

 through utilization of the oil, may have acquired an enhanced virulence. 

 The results of Gallaway et al. (1980) agree with the findings of the 

 above pond and laboratory experiments in that fish exposed to chronic, 

 low-levels of hydrocarbons in discharges developed external lesions and 

 fin rot which may have been attributable to Vibrio sp. 



Of the 34 red snapper from the BGOF examined for histopathological 

 anomalies, 62$ were characterized by gill hyperplasia and 47$ by 

 intestinal parasites, usually accompanied by intestinal inflammation, 

 fibrosis and lesions. Gill parasites were believed largely responsible 

 for the observed hyperplasia. No marked difference in the frequency of 

 the various anomalies was observed for production platforms vs. 

 satellite jacket populations or among seasons. Bacterial flora of red 

 snapper varied seasonally with Vibrio sp. usually the dominant form on 

 fish from each of the two habitats sampled. Hemolytic Vibrio spp., 

 which include representatives of potential fish pathogens, were well 

 represented on specimens from each structure during each season except 

 fall 1978 when none were isolated from any of the samples. Aeromonas 

 spp., which also include fish pathogens, were isolated from specimens 

 taken at the production platform in summer 1978 (27? of the total 26 

 colonies isolated from snapper tissue were Aeromonas spp.) and in 

 spring 1979 (15? of the total 47 isolated colonies). Aeromonas spp. 

 were not isolated from red snapper specimens taken at the control 

 structure during any season. No evidence of disease or red snapper in 

 poor condition was observed at any location or during any season. 

 Hydrocarbon contamination was variable (Middleditch and West 1 980) but 



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