Metabolic studies with laboratory microcosms were used to quantify 

 effects of excreted dissolved organics on microbial metabolism. 

 Fecal matter contributed to the system under field trophic conditions 

 on a 24-hour basis was measured. 



The extent to which the marsh offers protection to P. pugio was 

 determined by survival studies in the field with mixed, caged populations 

 of P^ pugio , P. vulgaris and Crangon septemspinosus . P. pugio has 

 exhibited physiological adaptation to low O2 in the water. The habitat 

 regularly becomes nearly anaerobic at night, and this probably is 

 the most significant stress in regard to eliminating the two potential 

 competitors from the area. (A. A 



'1 



Keywords: grass shrimp, tidal marshes, marsh ecosystems, fecal pellets, 

 U.S. coastal regions 



IV-E-14 



Mock, C. R. 1966. Natural and altered estuarine habitats of Penaeid 



shrimp. Proceedings of the Gulf and Caribbean Fisheries Institute 



19:86-98. 



This study demonstrates what can happen to a shrimp nursery area 

 when it is altered by bulkheading. Two areas were chosen--one adjacent 

 to an unaltered vegetative shore and the other near a concrete bulkhead. 

 Both had similar hydrology and sediment types, but differed in the amount 

 of organic detritus in the bottom sediments and in water depth. Intensive 

 sampling over a 10-month period indicated that 2.5 times more brown shrimp 

 ( Penaeus aztecus ) and fourteen times more white shrimp (P^. setiferus ) were 

 produced from the natural habitat than from the bulkhead area. This pre- 

 ference for the unaltered habitat depended on the physical rather than the 

 hydrologic characteristics of the habitat. (A. A.) 



Keywords: shrimp, estuarine habitats, detritus, environmental change, 

 Florida 



IV-E-15 



Rekas, A.M.B. 1973. The migration of post larval Penaeus aztecus and 



P. setiferus into a Louisiana nursery area (Airplane Lake). M.S. Thesis, 

 Louisiana State University, Baton Rouge, Louisiana. 79 pp. 



A study of the migration of post-larval brown shrimp ( Penaeus 

 aztecus Ives) into Airplane Lake, Louisiana, was started in March 1972. 

 Sampling gear included tide traps, a marsh sled, and a one-meter 

 plankton net. Stations were located in the most direct route to 

 Airplane Lake. Tide trap collection periods were six hours long for 

 a 24-hour period at 10 primary collection stations. A marsh sled was 



185 



