IV-E-12 



Kutkuhn, J.H. 1966. The role of estuaries in the development and perpetuation 

 of commercial shrimp resources. Pages 16-36 i£ American Fisheries 

 Society, a symposium on estuarine fisheries. Washington, D.C. 



This report summarizes knowledge concerning functional relationships 

 between the estuarine environment and commercial shrimp resources. 

 Discussion is largely restricted to North American species; attention 

 is focused upon situations evolving specifically as a result of the 

 rapid urban and industrial development of the estuary-rich Gulf coast. 



The association of shrimp and the brackish-water environment from 

 ontogenetic and ecological points of view is reviewed. Environmental 

 factors and biological factors such as water circulation, temperature, 

 salinity, vegetation, and substratum are discussed. The question of 

 continued productivity and perpetuation of shrimp stocks in the face 

 of man's modifications of estuaries is considered. Measures that could 

 be taken to counteract the effects of coastal wetland development are 

 discussed. (A. A. and B.W.) 



Keywords: estuaries, fisheries, shrimp, environmental changes, coastal 

 zones, U.S. Gulf coast 



IV-E-13 



Welsh, B.L. 1971. The grass shrimp, Palaemonetes pugio , as a systems 

 component of tidal marshes. Page 255 j_n D.S. Gorsline, ed.. Second 

 national coastal and shallow water research conference; abstract vol. 

 University of Southern California, Los Angeles. (Abstr.) 



Palaemonetes pugio , the grass shrimp, is an important component of 

 the marsh ecosystem. It processes organic material into highly 

 nutritious fecal pellets and it excretes large amounts of dissolved 

 organics which should stimulate microbial decomposition of the abundant 

 detritus. P. pugio accumulates organic material through rapid growth 

 in the fall with food readily available, then overwinters in the 

 marsh, at low metabolic cost to the system, thus maintaining a storage 

 of readily available animal food to sustain the reproductive growth 

 of immigrating fishes in early spring. The marsh, through rapid and 

 extreme fluctuations of temperature, salinity and oxygen concentration, 

 provides P. pugio protection from competitors and periodic relief 

 from predation. 



Present work focuses on quantifying these important interactions. 

 Mark-recapture estimates reached 1.5 million shrimp in three acres 

 in October, dropping to 13,500 in July, with 1:1 sex ratio. Present 

 research indicates females spawn more than once per summer and spring 

 larvae do not grow fast enough to spawn in the fall. Only multiple 

 spawning satisfies the dynamics of population changes without mass 

 immigration of juveniles. 



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