water quality of the Bay is to take this or a similar 

 general conceptualization of the system and esti- 

 mate magnitudes (at least relative magnitudes) of 

 the flows. It will not be easy. An example of the 

 kind of information and calculations required is 

 given in appendix B, a rough attempt to quantify 

 carbon fixed in the Bay system by marsh plants, 

 seagrasses, and phytoplankton, and to compare 

 that quantity to carbon imported by rivers. Rela- 

 tive flow information can be useful for manage- 

 ment. The largest inputs to primary production are 

 most important to protect. The largest point or 

 nonpoint sources of pollutants arc the most impor- 

 tant to regulate. The nutrient regeneration path- 

 ways having the highest turnover rate should be 

 measured accurately so that the waste-treatment 

 capacity of the system can be calculated. The eco- 

 system context provides a perspective on the rela- 

 tive importance of various management problems, 

 if quantitative information can be obtained. 



In a hierarchical approach to the Bay ecosys- 

 tem, such as currently taken, subsystems are 

 studied. Practicality dictates some subdivision of 

 the ecosystem for study purposes, and a communi- 

 ty approach (seagrasses, plankton, fishes, etc.) is 

 workable. It is important to include information 

 about exchanges between the particular communi- 



ty under study and the rest of the system (seagrass 

 export of detrital carbon, consumption of zoo- 

 plankton by fishes, proportions of phytoplankton 

 production consumed by various grazers) as well as 

 interactions within the subsystem itself. Quantita- 

 tive information, with seasonal and spatial varia- 

 tions or year to year variations, is most useful. 



Whenever quantitative estimates of any of the 

 model compartments or flows are made for any part 

 of the Bay system, an attempt should also be made 

 to extrapolate the estimates to the whole Bay for a 

 year. If such an extrapolation cannot be made, the 

 information necessary to complete it should be 

 identified. If an extrapolation is made, the underly- 

 ing assumptions on spatial and temporal variations 

 should be defined. 



The attempt to quantify standing stocks and 

 annual total flows for the conceptualized Bay sys- 

 tem may eventually lead to development of a simu- 

 lation of Bay ecology. In the meantime, it provides 

 a mean^ for examining a variety of assumptions 

 about dynamics of subsystems in the context of 

 the whole ecosystem. 



A list of specific research questions of concern 

 to scientists interviewed for this project is presented 

 in appendix C. 



REFERENCES 



Adams, S. M. 1976a. Feeding ecology of eelgrass fish com- 

 munities. Trans. Am. Fish Soc. 105:514-519. 



Adams, S. M. 1976b. The ecology' of eelgrass, Zostera mari- 

 na (L.), fish communities 1. Structural analysis. J. Exp. 

 Mar. Biol. Ecol. 22:292. 



Adams, S. M. 1976c. The ecology of eelgrass, Zostera ma- 

 rina(L.) fish communities II. Functional analysis. J. 

 Exp. Mar. Biol. Ecol. 22:292-311. 



Axelrad, I). M. 1974. Nutrient flux through the salt marsh 

 ecosystem. Ph. D. Dissertation. William and Mary Uni- 

 versity. 134 pp. 



Bigelow, II. B., and W. C. Schroeder. 1953. Fishes of the 

 Gulf of Maine. U.S. Fish and Wildl. Serv., Fish. Bull. 53. 

 577 pp. 



Biggs, R. B., and D. A. Flemer. 1972. The flux of particulate 

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Boesch, D. F., M. L. Wass, and R. W. Virnstein. 1976. The 

 dynamics of estuarine benthic communities. Pages 177- 

 196 in L. E. Cronin, ed. Estuarine processes. Vol. I. 

 Academic Press, New York. 



Cronin, L. E., and A. J. Mansueti. 1971. The biology of an 

 estuary. Pages 14-39 in A symposium on the biological 

 significance of estuaries. Sport Fishing Institute, Wash- 

 ington, D.C. 



Dale, M. B. 1970. Systems analysis and ecology. Ecol. 51: 

 1-16. 



Green, K. A. 1975. A simulation of the pelagic ecosystem 

 of the Ross Sea, Antarctica: a time varying compart- 

 mental model. Ph. D. Dissertation. Texas A&M Univer- 

 sity. 187 pp. 



Hacfner, P. A., Jr. 1971. Avoidance of anoxic conditions by 

 sand shrimp, Crangon scptcmspinosa Say. Chesapeake 

 Sci. 12:50-51. 



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