|Session VI: Bird & Animal Studies
||Abstract #: 97603
POPULATION BIOLOGY OF THE RIVERINE GRASS SHRIMP, PALAEMONETES PALUDOSUS AND ITS RESPONSE TO WATER-LEVEL CHANGE IN EVERGLADES MARSHES
NMFS, 75 Virginia Beach Dr., Miami, FL 33149
William F. Loftus
USGS-Biological Resources Division, Everglades National Park Field Station, 40001 State Rd. 9336, Walt Dineen Homestead, FL 33034
is abundant in Everglades marshes and serves as an important link in the marsh food web. Only one other study has investigated the life history and ecology of this species in Everglades marsh habitats, but the conclusions of that study are questionable because of an inherent bias in the pull-trap sampling gear used. We used an improved sampling gear, the throw trap, to examine the responses of riverine grass shrimp to hydrological patterns in the Shark River Slough marshes of Everglades National Park, during a six year period. We analyzed shrimp density, biomass, fecundity, reproductive seasonality, and size of maturity in long-hydroperiod marshes and in hydrologically challenged, short-hydroperiod areas. Prawn density and biomass were significantly lower in areas subjected to frequent dry-downs than they were in areas with sustained flooding. Although previously published pull-trap data indicated that shrimp abundance declined during an extended high-water period, data from our study show instead that the density of P. paludosus
increased during a period of prolonged high-water. Based on the results from the more accurate throw-trap gear, we conclude that frequent dry-downs will produce degraded marshes with reduced standing stocks of aquatic animals.