2004 UC Proceedings Abstract
Environmental Predictors of Dolphin Density: ArcGIS in Marine Biology Track: Ecology and Conservation Author(s): Paula Moreno, Bernd Wursig, Michael Mathews The factors underlying bottlenose dolphin distribution in estuaries are unclear. Our study investigates whether physical variables (salinity, water temperature, depth, distance to the Gulf) and anthropogenic variables (shrimpers, boat traffic) are good predictors of dolphin density in the Galveston Bay Estuary. We used ArcGIS to create software tools to determine survey effort and dolphin density using GPS tracks, relate environmental variables to dolphin density, and maintain equal detectability by excluding from the analysis dolphins sighted further than 200 m from the transect line. We demonstrate that the heterogeneity of dolphin density in estuaries is accounted for by a few environmental variables. We also discuss the integration of photo-identification techniques with GIS to determine group association patterns and individual home ranges. This approach highlights the role of GIS tools in the study and conservation of marine species. Paula Moreno Texas A&M University at Galveston Wildlife & Fisheries Sciences 4700 ave U, Bldg.303 Galveston , TX 77551 US Phone: (409)740-4718 Fax: (409)740-4717 E-mail: pmoreno@tamu.edu Bernd Wursig Texas A&M University at Galveston Marine Biology 4700 Avenue U, Bldg. 303 Galveston , TX 77551 US Phone: (409)740-4413 E-mail: wursigb@tamug.tamu.edu Michael Mathews Texas A&M University Mathematics Dept. of Mathematics, Texas A&M University College Station , TX 77843-3368 US Phone: (979)822-6750 E-mail: mathews@math.tamu.edu |
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