Factors influencing the growth, recruitment success, and distribution of Farfantepenaeus aztecus (Crustacea:Penaeidae) in high and low salinity salt marshes

Abstract

Densities of brown shrimp (Farfantepenaeus aztecus) were compared between high and low salinity salt marshes in Galveston Bay, Texas. Growth rates within the high salinity study area (West Bay) were estimated during the peak immigration period. Relationships between F. aztecus density and growth were related to both physical and biological parameters. Density was most significantly related to salinity and prey abundance. Growth rates were positively correlated with temperature and salinity. Brown shrimp were more abundant in West Bay than in the low salinity study area (Trinity River Delta). Peak abundances were observed during the spring at both study areas, with the exception of Trinity River Delta in 1997. During 1997, excess rainfall on the Trinity River watershed resulted in high volume river flow and reduced the salinity in the Delta to near zero. This high volume river flow limited the effective nursery grounds in the Galveston Bay ecosystem to higher salinity areas. It appears that physical parameters (i.e. salinity, temperature, river flow) and benthic infaunal abundance may determine the utilization of salt marshes by brown shrimp post-larvae and juveniles.