567 



BASELINE STUDIES 



Purpose 



The most important gaps to be filled by a baseline stud}^ are a knowl- 

 edge of the physical and chemical characteristics, identification, dis- 

 opinion that our most important knowledge gaps and thus the most 

 tribution, diversity, and abundance of resident and nonresident organ- 

 isms, exhaustive studies of their interactions, and the underlying causes 

 for these characteristics. This would permit classification of each es- 

 tuary into a characteristic habitat type and prediction of the produc- 

 tivity of fish, shellfish, wildlife, and other renewable resources for each 

 habitat. Properly conducted baseline studies would increase under- 

 standing 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 question of how much natural ha- 

 bitat — 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 

 estuaries relatively unaffected by man's activities. These pristine areas 

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

 modified to various degrees by human activities. It is extremely diffi- 

 cult to assess changes in the productivity or the decline or disappear- 

 ance of economically important species without sufficient background 

 information. In some cases, such changes can be attributed fairly 

 accurately to specific causes such as pollution, overexploitation, or 

 natural variation. On the other hand, the general decline of a species 

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

 the Pacific Northwest, suggests subtle ecological changes which are 

 much more difficult to assess. It would be invaluable to be able to com- 

 pare existing water quality conditions in given estuaries with condi- 

 tions as they were 50 years ago. One wonders, for example, how sea- 

 sonal and annual stream flow regimes have changed due to human 

 activities in watershed areas and how such changes have affected the 

 estuarine environment and hence the indigenuous biota. 



Necessary kinds of informationi, j 



The information needed as a base for technical management should 

 be in the form of an outline describing the Nation's coastal areas. To 

 resolve questions of best estuarine use, necessary information includes 

 the following: size and shape, existing water quality, degradation, 

 sources and types of wastes, climate, hydrology, circulation, ecology, 

 present and potential habitat value, identification, distribution and 

 abundance of organisms, physical modifications, bathymetry, and 

 bottom conditions. 



42-847 O— 7C 



