Using estuarine landscape structure to model distribution patterns in nekton communities and in juveniles of fishery species

摘要

Spatial relationships between distribution patterns of many species and vegetated habitats over multiple scales have been used in terrestrial ecosystems to help identify and map important areas for conservation and management. This approach is not widely used in characterizing habitat use of nekton species in estuaries, but it has great potential because these systems contain fairly discrete vegetated habitat types, and the distribution of nekton species can be influenced by the spatial arrangement of habitat. We examined the spatial relationships between estuarine habitats and nekton species to help map estuarine nekton communities for use in conservation planning. Using a Geographic Information System (GIS), we measured area (m~2) and edge density (m km~(-2)) of estuarine habitats over multiple scales in Charlotte Harbor, Florida (USA). We used redundancy analysis (RDA) to examine spatial patterns of nekton community composition, habitat, and local habitat characteristics. RDA revealed that spatial patterns in nekton community composition were most highly correlated with distance from the nearest pass to the Gulf of Mexico (r = -0.97) and with salinity (r = 0.94) and area of continuous seagrass habitat (r = 0.91). We used GIS maps of 2 variables (distance from the nearest pass and area of continuous seagrass habitat) to model spatial patterns in nekton community composition and the distribution of several juveniles of fishery species (red drum Sciaenops ocellatus, gray snapper Lutjanus griseus, lane snapper L. synagris, sand seatrout Cynoscion arenarius, and spotted seatrout C. nebulosus). The results suggest that incorporating measures of habitat area (over multiple scales) and spatial position into spatial models of nekton distribution is useful in conservation and management planning.