However, readily available historical data, which consists of infor- 

 mation already computerized or collected by local, state, and 

 federal agencies, may not address the specific problems being 

 investigated in each estuary. Historical data are also incomplete 

 and limited to specific regulatory programs. To overcome these 

 limitations, new sources of data are identified and information is 

 collected from virtually all possible sources — scientists, academic 

 and research institutions, and public health and living resource 

 agencies. Characterization should benefit from previous, published 

 work as much as feasible; however, many of the analyses that will 

 be done will require access to original data for manipulation. 



Because collecting new scientific information is generally quite 

 costly, historical data are used to set priorities for the kinds of new 

 information needed for the characterization effort. These data are 

 also used to shape new sampling and monitoring programs needed 

 to define specific problems. 



Characterization proceeds through the following major steps: 



• Identifying the most significant problems for investigation; 



• Collecting priority data sets; 



• Identifying data management support; 



• Screening priority data sets; 



• Determining estuary segments; 



• Analyzing data; 



• Considering significant gaps in available data; 



• Reporting results in both peer-reviewed technical publica- 

 tions and public documents; and 



• Preparing a characterization report or a series of charac- 

 terization reports. 



The relationship among these steps is presented in Figure 3.1 . 



The first step in the characterization process is identifying the most 

 important environmental problems in the estuary. This activity is 

 conducted by the Management Conference and therefore cannot 

 begin until a management framework is set up. Because all the 

 problems cannot be addressed, it is critical to rank them so that 

 effort and funding levels can be allocated effectively. The Manage- 

 ment Conference must establish criteria by which it will define and 

 rank environmental problems for characterization. 



Overestimating the severity or significance of certain problems can 

 divert attention from those that actually deserve greater concern. 

 The presence of toxic contaminants in the tissue of fish, for ex- 

 ample, may capture widespread publicity and interest because of 

 its potential effect on human health. However, the incidence of such 

 contamination may be limited to specific sites. On the other hand. 



Characterization 

 Steps 



Identification and Ranking 

 of Priority Problems for 

 Study 



25 



