569 



pie, will there be more fouling and wood borer problems ? Is just the 

 removal of pollution enough to reclaim an area or do we need to 

 develop techniques for rehabilitating despoiled estuarine areas and for 

 increasing fish and wildlife production in low value habitats? How 

 do we reconstruct a marsh after dredging, filling, and channelization 

 projects, if, in fact, we can reconstruct a marsh ecosystem? Another 

 need is to establish the time required for an estuary despoiled by over- 

 fertilization and decreased flushing to reestablish a normally diverse 

 flora and fauna upon stoppage of nutrient input and increase in 

 flushing rate. This could be accomplished by constructing experimental 

 embayments using survey data available for known polluted areas; 

 and by developing model analogs based upon existing survey data and 

 experimental results. Progress on reconstruction and rehabilitation 

 of a despoiled estuarine area is based again on the information which 

 would result from exhaustive detailed baseline studies described 

 earlier. 



Ecosystem management 



The use of systems analysis techniques to determine the effects of 

 various changes in the environment and harvesting techniques on 

 population levels is extremely productive. It seems that some of the 

 very critical problems of estuarine and Continental Shelf resources, 

 such as trash fishing, may be amenable to such analysis. In no other 

 way can we ever hope to determine what the effect of removal of a 

 certain portion of a population at a given age would have on the ability 

 of the population to survive and multiply. Based on this kind of 

 data, we could satisfy the need to develop better estuarine husbandry 

 programs, and aquaculture might be more profitably and productively 

 pursued. Fish production might be increased by altering Currents 

 and by other means. Mitigating effects of environmental alterations, 

 controlling disposal of waste products, controlling fish diseases ahd 

 predators, and developing genetic strains of desired species more suited 

 to moderately disturbed habitats might possibly ensue from a 

 sophisticated analysis of the above factors. Certainly we should know 

 more about the effects of any changes in the estuarine environment 

 on the increase or buildup that might be expected of aquatic weeds, 

 pest species of insects and other arthropods, and diseases and predator 

 species that may reduce populations of desirable organisms or inhibit 

 recreational uses of estuarine a^eas. \ 



BIOLOGICAL STUDIES 



Estuarine biological systems are extremely complex: when compared 

 to fresh water or truly marine environments. The areas between the 

 fresh water and the sea remain the biological link between the systems 

 which, if broken, will result in the elimination of many valuable 

 resources. The planktonic stages which are characteristic of life his- 

 tories of species having commercial or recreational importance are 

 especially vulnerable to environmental changes. 



Sources of food 



The complicated food chains, associated with the polymorphic life 

 histories of estuarine organisms, are poorly understood. For example. 



