2nd UF Water Institute Symposium Abstract

Submitter's Name Matthew Lauretta
Session Name Poster Session: Hydrologic, Biogeochemical and Ecological Processes 2
Category Hydrologic, biogeochemical and ecological processes
Poster Number 228
Author(s) Matthew Lauretta,  University of Florida
  Thomas Frazer,  University of Florida
  William Pine, University of Florida
  Eric Nagid, Florida Fish and Wildlife Conservation Commission
  Increased nutrient loading in Florida’s spring-fed, coastal rivers: effects on habitat and faunal communities.
  Long-term research on spring-fed rivers along Florida’s central gulf coast indicates that rapid, large-scale changes in aquatic vegetation composition and biomass have occurred in several systems over the last decade. Aquatic macrophyte abundances have precipitously declined coincident with marked increases in nutrient loading rates and periphyton associated with the plants. The potential broader-scale consequences of nutrient over-enrichment on the ecological health and integrity of coastal rivers is currently unknown. The goal of this project was to provide the complementary fish and invertebrate data necessary to identify and characterize broad-scale ecological impacts associated with vegetative habitat loss. Our specific objectives were to quantitatively characterize the fish and invertebrate assemblages in two coastal rivers with contrasting vegetative habitat structure, and to quantify the food habits of fishes so that trophic relationships could be established. Invertebrate assemblages associated with submersed aquatic vegetation differed considerably between rivers with dissimilar vegetative habitats, while invertebrates assemblages associated with sediments were comparable in composition. Freshwater and saltwater fish abundances and biomass were significantly greater in river reaches where submersed aquatic vegetation was most prevalent, and the fish community structures were distinctly different between rivers. Crustaceans were found to be an important food source for fishes in both systems, and substantial differences were observed in the composition of crustaceans consumed in each river. This research suggests that large-scale changes in vegetative habitat may impact faunal community structure, abundance, biomass and trophic interactions in spring-fed, coastal rivers.