THE GULF OF MEXICO ECOSYSTEM: A COASTAL AND MARINE ATLAS
See related maps and narratives on Bathymetry, Sea Surface Currents and Atlantic Bottlenose Dolphin. Data Compilation and Mapping Methods The main source of data for Map 35 was the NOAA Cetacean Density and Distribution Mapping Working Group (Read et al., 2010). Model products were developed from the best available survey data and from models estimating density using predictive environmental factors (Best et al., 2007; Best et al., 2012). The NOAA Cetacean Density and Distribution Mapping Working Group categorized the model products in an information hierarchy, establishing a tiered level rating depending on source data and model processes employed. At the time this atlas was developed, the level of model data available for this species in the Gulf was rated as probability of occurrence, which was tier three in a five-level hierarchy (starting with the highest degree of data reliability): tier 1) Habitat Based Density, tier 2) Stratified Density, tier 3) Probability of Occurrence, tier 4) Records Exist, and tier 5) Expert Based Presence or Likely Absence. Probability of occurrence products are spatially heterogeneous predictions of the probability of encountering the species, population or guild across a grid covering the Gulf, based on environmental covariates. Two seasons of occurrence models are
available: spring and summer. The spring season of the occurrence models available for this species in the U.S. Gulf was used to illustrate the U.S. Gulfwide distribution. Data Quality Data quality for Map 35 is fair for the U.S. because, at present, these data describe distributions for only two of the four seasons. No analogous data were identified for waters of Cuba and Mexico or waters outside of the exclusive economic zones for the U.S., Mexico and Cuba. Hence, geographic and seasonal data gaps exist for this species in the Gulf. Synthesis and Conclusions Pantropical spotted dolphins are small oceanic dolphins that are likely present throughout the Gulf. The status of pantropical spotted dolphins in the Gulf is mostly unknown despite numerous confirmed sightings in U.S. waters. Studies are needed in the waters of Mexico and Cuba to assess abundance and distribution, which in combination with data from U.S. waters, will provide a more complete assessment of population size, dynamics and trends in the Gulf. Continued research, assessment and long-term monitoring are critical to determine any sublethal effects of the DWH oil disaster on pantropical spotted dolphins.
Text Citations Best, B. D., Halpin, P. N., Fujioka, E., Read, A. J., Qian, S. S., Hazen, L. J., & Schick, R. S. (2007). Geospatial web services within a scientific workflow: Predicting marine mammal habitats in a dynamic environment. Ecological Informatics, 2(3), 210 - 223. Best, B. D., Halpin, P. N., Read, A. J., Fujioka, E., Good, C. P., LaBrecque, E. A., Schick, R. S., Roberts, J. J., Hazen, L. J., Qian, S. S., Palka, D. L., Garrison, L. P., & McLellan, W. A. (2012). Online cetacean habitat modeling system for the US East Coast and Gulf of Mexico. Endangered Species Research, 18, 1-15. Davis, W. B., & Schmidly, D. J. (1997). The mammals of Texas – online edition. Lubbock, TX: Texas Tech University. Retrieved from http://www.nsrl.ttu.edu/tmot1/stenatte.htm Davis, R. W., Fargion, G. S., May, N., Leming, T. D., Baumgartner, M., Evans, W. E., Hansen, L. J., & Mullin, K. (1998). Physical habitat of cetaceans along the continental slope in the north-central and western Gulf of Mexico. Marine Mammal Science, 14, 490-507.
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