Table 42. Average CV and range/average SD for biochemical measures in Platichthys 

 stellatus (present study), Platichthys flesus (Stegeman et al., 1988; Addison and Edwards, 

 1988), and Pseudopleurotiectes americanus (Stegeman et al., 1987). 



*units were reported as nmol/B(a)p/min/mg protein 



It is apparent that the P. stellatus cytochrome P-450 system is highly responsive to 

 exposures to organic compounds. Total P-450, EROD, and P-450E activities were highest in 

 fish from the BK and/or OK sites which were located nearest known sources of potentially 

 P-450-inducing contaminants. These end-points indicated differences in response both among 

 the sites in the estuary and between sites within and outside the estuary. Experience with 

 the P. stellatus confirmed the patterns in response observed with P. americanus and scup in 

 New England and flounder in Norway. It is also apparent that these end-points are 

 excellent specific indicators of exposure to high molecular weight hydrocarbons in the 

 environment. The markedly different values obtained from highly induced fish versus fish 

 from reference areas facilitates determinations of site-to-site differences. 



In either laboratory exposures or in feral fish, the suite of total P-450/EROD/P-450E end- 

 points appear to respond to contaminants similarly among the species tested thus far. 

 While the P-450 suite of tests may indicate the successful response of fish to xenobiotics, and 

 may not necessarily reflect an adverse effect upon the longevity or fecundity of the animal, 

 the tests, nevertheless, are indicators of exposure to contaminants that may not be 

 quantifiable otherwise and that may cause subtle adverse effects. In conclusion, the suite of 

 total P-450/ EROD/P-450E measures appears to be very sensitive, correlated with some 

 contaminant data, relatively low in variability among fish from the same site and over a 

 similar range in response among species. 



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