VI-101 



and the underlying causes for these characteristics. This would per- 

 mit classification of each estuary into a characteristic habitat type 

 and prediction of the productivity of fish, shellfish, wildlife, and 

 other renewable resources for each habitat. Properly conducted base- 

 line studies would increase understanding of the causes and mechanisms 

 of natural and man-made fluctuations in species abundance. Baseline 

 studies would be necessary before considering the merit of preserving 

 certain estuaries in their present condition for future comparative 

 reference. Perhaps the most valuable benefit to be derived from 

 baseline studies is information bearing on the key management ques- 

 tion of how much natural habitat -- estuary, marsh, lagoon -- is 

 required for the maintenance and production of adequate numbers of 

 desired species of plants and animals. 



Studies of Unpolluted Estuaries 



Knowledge of baseline conditions is particularly important in estua- 

 ries relatively unaffected by man's activities. These oristine areas 

 serve as controls for ourposes of comparison with bays that have been 

 modified to various degrees by human activities. It is extremely 

 difficult to assess changes in the productivity or the decline or 

 disappearance of economically imoortant soecies without sufficient 

 background information. In some cases, such chanaes can be attributed 

 fairly accurately to specific causes such as pollution, over-exoloi- 

 tation, or natural variation. On the other hand, the general decline 

 of a species over a wide geographic area, such as the Olympia oyster 



