Highlights of 



Conclusions About 



the Usefulness of 



Finfish as Indicators 



Screening Across Estuaries 



Table 1.— Criteria for Using Finfish as Indicators of Toxic Contamination 

 The following criteria are essential: 



• Causality. There must be an unequivocal cause and effect relation- 

 ship between toxic pollution and the indicator. 



• Cost-Effectiveness. The indicator must be affordable and provide 

 enough data to warrant the amount of money spent. 



• Useability. Laboratories throughout the country must be able to use 

 the indicator. 



The following criteria would also be helpful: 



• Specificity 



— The method should be pollutant-specific. That is, its use should in- 

 dicate the effects of a specific pollutant or class of pollutants. 



— The method should be species-specific.That is, it should be ap- 

 plicable only to one or a limited number of fish species. 



• Applicability to small or large spatial scales 



— The method should permit identification of small areas of con- 

 tamination within the estuary. 



OR 



— The method should also permit locating the effect of contamina- 

 tion in large areas of the estuary. 



• Usefulness as an early or late indicator 



— The method should be usable as an early indicator of toxic con- 

 tamination. That is, it should be sensitive enough to demonstrate 

 an effect after brief exposure to low concentrations of pollutants. 



OR 



—The method should be useable as a late indicator. That is, it 

 should have a low degree of sensitivity and be capable of 

 demonstrating an effect after prolonged exposure to high con- 

 centrations of pollutants. 



Human Healtli Indicators 



The following discussion highlights workshop conclusions regarding 

 the usefulness of finfish as indicators of toxic contamination. 



Historical data on the abundance and distribution of fish populations 

 and on the concentration of contaminants in fish generally are 

 readily available. Therefore, these parameters are the most useful 

 early screening tools. The use of other indicators is more limited 

 because historical data are usually unavailable. Furthermore, cost 

 and time considerations preclude collecting large amounts of field 

 data during the screening phase. 



Concentrations of contaminants in tissues, or tissue residues, are 

 useful indicators of human health effects. Lesions, tumors, and 

 other histopathological changes are not useful for this purpose. 



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