571 



greatest extent possible through influence on permits for dredging, 

 filling, draining, or other modifications of estuarme zones. 



An extension of the study of necessary habitats would be to deter- 

 mine in quantitative terms, the importance of the estuary as a spawn- 

 ing area, and then its importance as a nursery area. These data on life 

 cycle events, population dynamics, food chains, nursery, habitat, 

 spawning area values, may exist already in one form or another, 

 but they are certainly not generally available. They need to be drawn 

 together in a way so that they can be used by the resource manager. 



WATER QUALITY CONSIDERATIONS 



As indicated in the discussion on baseline studies, it is essential to 

 have a full knowledge of the characteristics of the receiving waters in 

 the development of a realistic program for pollution control and water 

 quality management. In most cases, the pollutional control characteris- 

 tics are unknown for the various estuarine areas. These characteristics 

 need to be established for each estuary. While some basic data concern- 

 ing expected norms can be interchanged among estuaries, much work 

 with each individual system is needed to establish the validity of such 

 interchanges. 



Effects of combined wastes 



Residential, recreational, agricultural, and industrial development 

 of the estuarine zones is proceeding at a rapid rate. These activities 

 frequently result in highly complex waste waters from many sources 

 that eventually become mixed in the bays and oceans. While the toxic 

 and other characteristics of some of the individual types of waste water 

 have been studied, ejffects of combined waste waters, including syner- 

 gistic and antagonistic effects, are largely unknown. 



Water quality requirements for fish, other aquatic life, and wildlife 



Having learned something of the water quality of the estuaries, the 

 next step is to ascertain the water quality requirements for the estua- 

 rine and near-shore environment. At the present time, knowledge in 

 this area is incomplete, with the resulting tendency to use criteria that 

 have been developed for fresh water systems. Because of the com- 

 plexity of the marine system, many of the measures used in the fresh 

 water environments are of questionable value or at least difficult to 

 interpret. Although there has been a considerable amount of work 

 done, there still exist gaps in our knowledge of water quality require- 

 ments for the various finfish, shellfish, organisms that comprise their 

 food chains, and other marine species. Further, much of the work 

 that has been done on the subject has addressed itself to toxicity limits 

 which determine the level of various materia!ls that are fatal to marine 

 species. This approach is undesirable because the objective for man- 

 agement of the marine environment is not to determine the minimum 

 level or quality that can be tolerated, but is to maintain the quality 

 that is necessary to sustain and enhance the fishery production and 

 other beneficial uses of marine areas. This requirement is of particular 

 importance because the estuaries and near-shore zones comprise the 

 nursery grounds and habitat for 75 percent of the important marine 

 species. 



