HR: 08:45h
AN: NB41F-02 INVITED     [Abstracts]
TI: Ecological Importance of Tidal Fresh Waters: Longitudinal Patterns in Biotic Diversity in Mid-Atlantic Coastal Rivers
AU: * Smock, L A
EM: lsmock@saturn.vcu.edu
AF: Department of Biology, Virginia Commonwealth University, Richmond, VA 23284 United States
AU: Viverette, C B
EM: cbvivere@vcu.edu
AF: Center for Environmental Studies, Virginia Commonwealth University, Richmond, VA 23284 United States
AU: Garman, G C
EM: gcgarman@vcu.edu
AF: Department of Biology, Virginia Commonwealth University, Richmond, VA 23284 United States
AU: Garman, G C
EM: gcgarman@vcu.edu
AF: Center for Environmental Studies, Virginia Commonwealth University, Richmond, VA 23284 United States
AU: McIninch, S P
EM: spmcinin@vcu.edu
AF: Department of Biology, Virginia Commonwealth University, Richmond, VA 23284 United States
AU: McIninch, S P
EM: spmcinin@vcu.edu
AF: Center for Environmental Studies, Virginia Commonwealth University, Richmond, VA 23284 United States
AB: Tidal freshwaters represent the interface between non-tidal freshwater habitats and estuaries and are a substantial proportion of the coastal habitats on the Atlantic Slope. They typically are considered depauperate compared to upstream riverine and downstream estuarine habitats. The objective of this study was to quantify patterns in fish and macroinvertebrate community composition and biodiversity along the James River, Virginia continuum, testing the prediction that the tidal freshwater section supported a unique species assemblage lower in biodiversity than the other sections of the river. A second objective was to quantify the impact of non-native species of fishes on patterns of community composition along the river continuum. Data were collected from nearly 50 locations along the river. Multivariate analyses identified fish and macroinvertebrate assemblages unique to specific river reaches. The results show that species assemblages shift along a longitudinal gradient. Contrary to predictions, species richness of fishes increased in a downstream direction but peaked in the tidal freshwater reach. Occurrence of non-native species, particularly piscivores, influenced fish community structure along the entire river. The results indicate that tidal freshwater reaches combine characteristics of both riverine and estuarine ecosystems in a manner typical of an ecotone or habitat edge.
DE: 4815 Ecosystems, structure and dynamics
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly