Indicators in the 

 Low-Level Suite 



Finfish indicators in the low-level suite are useful primarily for 

 making nationwide comparisons of estuaries, and for identifying 

 regional problems. The objective is to assess, on a preliminary 

 basis, the extent and severity of ecological effects caused by toxic 

 contamination. Because these indicators can be applied to analyze 

 existing information, they are particularly appropriate for the early 

 stages of estuary programs. During Phase 1 , the Planning Initiative, 

 they can be used as evidence in defining and ranking problems to 

 be addressed by the Management Conference. During Phase 2, 

 Characterization and Problem Definition, they can be used to 

 establish status and trends. 



The following indicators are from the low-level suite. 



Sources of information. Information about problems related to 

 toxic contamination, such as fishery closures, is compiled from 

 various sources. These include newspaper articles, anecdotes, 

 published reports, and newsletters. 



Gross pathology. Reports of obvious anatomical abnormalities 

 like fin erosion, skeletal deformities, and tumors help to identify the 

 presence of a problem. 



Behavioral abnormalities. Changes in behavior, such as 

 avoidance or attraction of fish to contaminants, can be measured 

 by comparing the reactions of fish before and after they are 

 exposed to the test material. Other behavioral changes, for ex- 

 ample erratic swimming or lethargy, may indicate specific modes 

 of toxicity like neurological or metabolic dysfunction. 



Distribution and abundance. Profiles of the spatial distribution 

 and abundance of a species may be directly related to mortality 

 caused by exposure to toxics, or to behavioral changes like 

 avoidance and attraction cited above. 



Tissue residues, especially in commercial species. Fish tissue 

 should be analyzed for the concentration of some or all of the 129 

 priority pollutants. Bioaccumulation of certain substances in fish 

 indicates not only that the contaminant is in the environment, but 

 that it may potentially threaten the environment and human health. 



Finfish indicators in the high-level suite are useful primarily for 

 longer term monitoring studies. Monitoring is conducted in targeted 

 studies to answer specific scientific or managerial questions raised 

 during the problem definition and characterization phase. These 

 indicators are also useful biological monitors of health or stress in 

 the estuary. Because of their sensitivity, they may be used to 

 determine the effectiveness of management actions. Methods in 

 the high-level suite require collecting specific laboratory or field 

 data. 



Indicators in the 

 High-Level Suite 



C5 



