583 



Parallel studies should be done for other disease-causing organisms 

 such as the viruses and microscopic organisms such as the viruses and 

 microscopic organisms that produce toxicants such as Clostridiv/m 

 and Gonyaulax. 



Another group of pathogens sorely in need of research and under- 

 standing are those which affect desirable estuarine organisms. Crabs in 

 Chesapeake Bay have been known to suffer epidemics of viral diseases. 

 Oysters in the Northeast have been subjected to, and nearly eliminated 

 from large areas, by the disease MSX. A great deal of work must be 

 done to determine the extent and variety of these disease-causing 

 organisms and to develop control measures so that desirable crops 

 might be maintained. The ability to protect economically important 

 organisms is essential before aquaculture can be pursued on a profitable 

 basis. 



SUMMARY 



1. The cause and effect relationships of nutrient supply, bacterial 

 action, and algal growth processes must be better understood. Environ- 

 mental conditions inducing and supporting nuisance eutrophication 

 must be controlled. 



2. Detailed knowledge of the environmental requirements and the 

 ecology of estuarine bacteria should be developed. 



3. More must be learned about coliform bacteria as indicators of 

 pollution. Methodology appropriate for estuarine waters must be 

 made more definitive. 



4. Methodology for detection, identification, and quantitation of 

 Salmonella and other disease organisms must be developed. The per- 

 sistence and transmission of disease organisms must be better under- 

 stood and methods of control developed. 



5. A great deal of work must be done to determine the extent and 

 variety of organisms which cause disease in desirable organisms, and 

 control measures developed. 



Section 7. Physics and Mathematics 



The specific kinds of research that must be done within the physical 

 and mathematical aspects of estuarine management fall generally into 

 the broad categories of hydraulics, sedimentation, physical modifica- 

 tion and structures, and physical and mathematical modeling. 



HYDRAULICS 



Scofe 



The briefest statement of what is needed in hydraulics is an under- 

 standing of the water dynamics of the estuary, including details of 

 tidal and current regimes, an evaluation of the effects of river flow, 

 rates of water exchange, characteristics of flushing, and all of the other 

 phenomena related to the nature and behavior of the fluid portion of 

 the estuarine zone. 



Flow characteristics 



A starting point in understanding the hydraulics of an estuarine 

 system would be an analysis of macroscopic flow and circulatory pat- 

 terns including seasonal discharges from rivers, seasonal temperature 

 inputs from rivers, density asj)ects (completely mixed versus stratified 



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