McDERMOTT EHRLIC'H ET A I, Clll.l >KINA TKI ) 1 1 YI)R< X AKI'.i >NS IN IHIVKR SOI.K 



174 ± 3 mm and 193 ± 6 mm, respectively; the 

 respective body weights were 78 ± 5 g and 115 ± 

 11 g. Measurements for the diseased (n = 14) and 

 unaffected (n = 8) Orange County specimens 

 were 195 ± 4 mm and 182 ± 7 mm SL, 119 ± 8 g 

 and 98 ± 10 g, respectively. These fish were gen- 

 erally 3 to 4 yr old, though some were younger and 

 some older. The mean standard lengths of several 

 age-classes of over 425 southern California Dover 

 sole collected at coastal locations by small otter 

 trawl were as follows: age-class I, 70 mm; II, 

 140 mm; III, 170 mm; IV, 190 mm; V, 220 mm 

 (Mearns and Harris 5 ). 



Muscle tissue subsamples were excised from 

 each of the specimens when they were semi- 

 thawed. The dissections were performed on 

 cleaned Teflon 6 sheets, using carbon steel imple- 

 ments. The tissue samples were placed in glass 

 containers, which had been heated overnight in 

 a kiln at 538°C (1,000°F). The samples were then 

 frozen until chemical analyses were performed. 



Levels of total DDT and total PCB were mea- 

 sured in the samples using electron-capture gas 

 chromatography (Young et al. 1976b). The com- 

 ponents were identified by retention time; values 

 were derived by comparing the peak heights of the 

 samples with the peak heights of standards. 



RESULTS AND DISCUSSION 



Migration Hypothesis 



The hypothesis that the diseased Dover sole 

 collected off Orange County had migrated from 

 the Palos Verdes shelf was tested by measuring 

 the levels of total DDT and total PCB in muscle 

 tissue from specimens with and without eroded 

 fin tips from both locations. To discount possible 

 seasonal variability, all results obtained for each 

 disease category at an individual station were 

 combined on a quarterly basis. To discount possi- 

 ble station variability, only data from those sta- 

 tions for which both diseased and unaffected 

 specimens had been analyzed were used. For com- 

 parison, we used the median total DDT and total 

 PCB concentrations for diseased and unaffected 

 fish. Tables 1 and 2 present the results for total 

 DDT and total PCB, respectively. 



TABLE l, — Median concentrations (milligrams per kilogram 

 wet weight) of total DDT in muscle tissue of Dover sole, with 

 and without eroded fins, collected off Palos Verdes Peninsula 

 and Orange County, 1974 quarterly trawl series. 



TABLE 2. — Median concentrations (milligrams per kilogram 

 wet weight) of total PCB in muscle tissue of Dover sole, with 

 and without eroded fins, collected off Palos Verdes Peninsula 

 and Orange County, 1974 quarterly trawl series. 



5 Mearns, A. J., and L. H. Harris. 1975. Age, length, and weight 

 relationships in southern California populations of Dover sole. 

 South. Calif. Coastal Water Res. Proj., Rep. TM 219. 



6 Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



Using the Mann- Whitney Latest, we found no 

 significant difference (P>0.20) between total 

 DDT concentrations in the muscle tissue of dis- 

 eased fish from the Orange County and Palos 

 Verdes regions. The overall median total DDT 

 concentrations were 13 and 18 mg/kg wet weight, 

 respectively. In contrast, there was a significant 

 difference (P<0.05) between total DDT levels in 

 the unaffected fish from the two regions (over- 

 all medians of 1.1 and 11 mg/kg wet weight, 

 respectively). 



In this study, the overall median values ob- 

 tained for total DDT levels in diseased Dover 

 sole from both areas and in the unaffected fish 

 from Palos Verdes were 10 or more times greater 

 than the overall median value obtained for the 

 unaffected Orange County specimens. McDermott 

 and Heesen (1975) had previously found that the 



515 



