THE VALUE OF SALT-MARSH EDGE VS INTERIOR AS A HABITAT FOR FISH AND DECAPOD CRUSTACEANS IN A LOUISIANA TIDAL MARSH

Flume nets of various lengths and a 3-m seine were used to sample the fishes and macrocrustaceans using a flooded Louisiana salt marsh and t he adjacent tidal creek. The experiment allowed for species-specific c omparisons of the flooded marsh at the creek edge versus the interior. Of the 37,667 organisms collected in flume nets from January through November 1989. 89% were decapods (nine species) and 11% were fish (29 species). An additional 18,539 organisms (75% decapods and 25% fish) w ere collected from concurrent seine samples taken from July through No vember. Comparison of catches among different flume lengths and low ti de versus high tide seine collections revealed distinct patterns of ma rsh habitat utilization. Densities of most organisms were highest with in 3 m of the water's edge, but significant numbers of marsh-resident fish species used the interior marshes. The edge marshes appeared to b e used by both transient and resident species; however, the interior m arshes were used primarily by marsh-resident species (Cyprinodontiform es and Palaemonetes sp.) that are excellent food sources for adult tra nsient-species. Four zonations of marsh use are described for transien ts, residents, and rare species.