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Tuesday, May 27, 2008 - 11:45 AM
158
The role of instream habitat and nutrient enrichment in structuring fish communities in central Texas streams
Jason M. Taylor, Charles E. Stanley, and Ryan S. King. Department of Biology, Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX 76798-7266
Nutrient pollution is a major cause of impairment in rivers and streams. Few studies have observed linkages between nutrient enrichment and fish assemblage structure in natural streams. To explore this relationship we evaluated the role of phosphorus enrichment in structuring fish assemblages relative to other environmental variables. Non-metric multidimensional scaling (NMS) ordination was performed using fish species abundance data collected at 26 locations representing a phosphorus gradient. NMS yielded a 3-dimensional solution that explained 82% of the original distance in ordination space. Environmental vectors most correlated with ordination axes included % pasture, sediment cover, total phosphorus (TP), C:P ratios of benthic algae, riparian buffer width, % sand, bank erosion, flow status and velocity depth regimes. Simple Mantel tests indicated that fish assemblage structure and some of the important environmental variables were spatially autocorrelated. However relationships between fish assemblage structure and environmental variables were still strong after removal of spatial influence through partial Mantel tests. Pure-partial Mantel tests that accounted for other environmental variables further revealed that several variables explained unique variation in fish assemblage structure and suggest that both instream habitat and nutrient pollution are structuring fish communities in central Texas streams.
Web Page: fish, nutrients, habitat
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See more of The Nabs 56th Annual Meeting (25-28 May, 2008)
See more of Contributed Sessions
See more of The Nabs 56th Annual Meeting (25-28 May, 2008)