During the characterization phase, a preliminary list of priority 

 problems should be proposed. If there is a decrease in the abun- 

 dance of fish, a high incidence of diseased fish, or a potential threat 

 to human health due to toxins in fish, the following steps are 

 warranted. 



• Use the low-level suite of indicators; and 



• Synthesize historical data on the abundance of fish, the 

 amount and type of tissue residues, and the incidence of 

 disease. 



At the same time, collect and analyze data on toxic contamination, 

 sources, and pollutant loads. If the analysis shows a correlation 

 between toxic contamination and changes in fish, the program may 

 choose to do the following: 



• Conduct field sampling to define further the nature and extent 

 of the problem; 



• Conduct laboratory toxicity studies to identify the pollutants 

 of most concern; and 



• Identify any probable current sources of those pollutants and 

 reduce current loadings. 



Furthermore, if toxic contamination is the cause, follow-up activities 

 should be conducted. The program should identify pristine refer- 

 ence areas and summarize all available data on these areas. 



After the contaminant problem has been characterized and neces- 

 sary critical information identified, a focused monitoring program 

 should be designed to assess correlations between specific 

 toxicants, or groups of toxicants, and the effects on fish. Indicators 

 from the high-level suites should be used during this phase. To 

 design the monitoring program, first select the appropriate species. 

 Follow the guidelines developed in the workshop. 



• A relatively nonmotile, nonmigratory species should be used. 



• Commercially or recfeationally important species are 

 preferable. 



• Species for which baseline data are available are preferable. 



• Provisions for making an archive of tissue samples for future 

 use in assaying additional indicators should be included. 



How to Use Finfish 

 Indicators in an 

 Estuary Program 



Years One and Two 



Years Three and Four 



C7 



