Utilization of natural and transplanted Texas salt marshes by fish and decapod crustaceans

Abstract

Mean values for stem density and above-ground biomass of Spartina alterniflora were consistently higher in transplanted marshes. Macro-organic matter (MOM) in the upper 5 cm of sediment was significantly lower in transplanted marshes. Densities of polychaetes and amphipods within transplanted marshes were positively correlated with MOM. Transplanted marshes had significantly lower densities of decapod Crustacea (primarily daggerblade grass shrimp Palaemonetes pugio and juvenile brown shrimp Penaeus aztecus) compared with natural marshes. This reduced utilization may have been a response to low densities of benthic food organisms, and densities of decapods were positively correlated with densities of prey in sediment cores. Densities of fish (dominated by darter goby Gobionellus boleosoma and pinfish Lagodon rhomboides) were similar between natural and transplanted marshes. These small fish may rely on salt marshes more for protective cover than for enhanced food resources; above-ground structure in the transplanted marshes may have adequately provided this function. -from Authors