specimens. Moraxella sp. were apparently a co-dominant with Vibrio 

 spp. during spring. There was no marked difference in the bacterial 

 flora of blennies taken from the production platform as compared to 

 those collected at satellite jacket habitats. No diseased blennies were 

 noted in any of the areas sampled. 



The crested blenny was a "clean" fish in terms of histopathological 

 anomalies. Other than a light infestation of microsporidean parasites, 

 no significant histopathological anomalies were detected in the 

 specimens examined. However, the average alkane concentration in this 

 fish was 6.79 ppm, higher than the mean levels observed for any other 

 fish from the BGOF (Middleditch and West 1980). Trace metal 

 contamination of blennies attributable to BGOF operations was not 

 indicated. 



Sheepshead were found to be "structure- faithful" fishes, and 

 density levels of sheepshead at platforms having contaminant discharges 

 were similar to densities at non-discharging structures. The most 

 notable histopathological finding with respect to sheepshead was the 

 veritable absence of any anomalous condition in tissue samples taken 

 from migrant specimens collected during the brief period of the spawning 

 aggregation observed in the BGOF in April. Typically, sheepshead 

 collected during other seasons (residents) exhibited five to seven 

 different tissue anomalies, with each condition represented in 20$ to 

 100$ of the specimens collected. With the exception of gill 

 hyperplasia, which was characteristic of all specimens collected during 

 the summer and in four of five specimens collected at the production 

 platform in fall, most of the anomalies in the tissues examined were 

 lesions associated with a parasite (e.g. nematodes). If the fish 

 collected during April were representative of a migrant population, it 

 would appear that resident sheepshead were characterized by a higher 

 degree of histopathological anomalies (or parasitism) than were 

 sheepshead which migrated in and out of the study area for spawning 

 purposes. 



Comparisons of condition of sheepshead at the treatment and control 

 structures were based upon specimens subsequently submitted for 

 histopathological and bacterial flora analysis. The data set was 

 reduced to the December 1978 and May 1979 collections, as the sheepshead 

 represented during April were not considered resident fish, and weights 

 were not obtained for the specimens analyzed from August. The 

 length-weight regressions for fish from the two habitats had equal 

 slopes, and although fish from the discharging platform were 10.6? 

 heavier than fish from the control structure, the differences were 

 non- significant . 



Sheepshead were characterized by the presence of petroleum alkane 

 contaminants in both liver (60O8 ppm) and muscle tissues (4.57 ppm) . 

 These levels were lower than that characteristic for blennies, but 

 higher than levels observed for fishes not trophically dependent upon 



65 



