they are nursery areas for many species, including menhaden, shrimp, 



mullet, tarpon, arid several sciaenids. The author states that 

 recommendations for managing estuaries based on narrow aspects of 

 the problem, without regard for the whole system, are a danger to 

 important sport and commercial fisheries. 



Too much emphasis is being placed on management based on primary 

 productivity because "high primary productivity does not necessarily 

 result in a high level of yield of the species desired by the sport 

 and commercial fisherman." Recommendations for management must 

 consider the life history and population dynamics of the species for 

 which management is proposed. (B.W.) 



Keywords: estuarine management, nursery areas, fisheries, primary 

 productivity 



IV-A-4 



Cain, S.A. 1968. Estuaries: our most endangered natural habitats. Pages 41-48 



ijX J.D. Newsom, ed., Proceedings of the marsh and estuary management 



symposium. Louisiana State University, Baton Rouge. 



Estuarine habitats are extremely productive areas, exceeding the 

 production of ordinary agricultural land by one order of magnitude and 

 that of deserts and deep oceans by two orders of magnitude. Constant 

 enrichment by topsoil from the land and the stirring of bottom sedi- 

 ments by winds and tides makes estuarine waters a rich mix for bacteria, 

 plant and animal plankton, shellfish, Crustacea, insects, finfish, tur- 

 tles, birds, and mammals. 



Estuaries are an ecosystem, rather than a single habitat, and com- 

 prise numerous subsystems. Differences in bottom materials (mud, peat, 

 sand), water depth, length of periods of submergence and emergence by 

 the tides, currents and exposures to winds, and other factors influence 

 the various communities in estuaries. 



These areas are also commercially valuable as fishing towns, resort 

 or recreation areas, industrial and trade centers, and transportation 

 centers. The problem is not that estuarine regions have many and varied 

 legitimate uses but that use must be carefully planned. Consideration 

 must be given to the costs and benefits of the alternatives so that 

 estuarine resources can be used to serve different needs, commercial 

 or developed and natural. 



The author suggests that cooperation among local and state governments, 

 the Corps of Engineers, and the Department of the Interior will protect 

 estuaries from destruction while allowing for maximum appropriate 

 utilization. (B.W.) 



Keywords: estuaries, habitats, productivity, marine ecosystems 



146 



