tion, with code 1 being a live animal and code 5 being mummified or ..... Sea World Research Institute, 7007 Sea World Dr., Orlando, FL 32821. Unpubl. data.
NOAA Technical Report NMFS 147
November 1999
Investigation of Unusual Mortalities of Bottlenose Dolphins along the Mid-Texas Coastal Bay Ecosystem during 1992 A. A. Colbert G. I. Scott M. H. Fulton E. F. Wirth J. W. Daugomah P. B. Key E. D. Strozier S. B. Galloway
U.S. Department of Commerce
NOAA Technical Report NMFS 147 A Technial Report of the Fishery Bulletin
Investigation of Unusual Mortalities of Bottlenose Dolphins along the Mid-Texas Coastal Bay Ecosystem during 1992 A. A. Colbert G. I. Scott M. H. Fulton E. F. Wirth J. W. Daugomah P. B. Key E. D. Strozier S. B. Galloway
November 1999
U.S. Department of Commerce Seattle, Washington
Investigation of Unusual Mortalities of Bottlenose Dolphins along the Mid-Texas Coastal Bay Ecosystem during 1992 A. A. COLBERT, G. I. SCOTT, M. H. FULTON, E. F. WIRTH, J. W. DAUGOMAH, P. B. KEY, E. D. STROZIER, and S. B. GALLOWAY Center for Coastal Environmental Health and Biomolecular Research at Charleston National Ocean Service, NOAA 219 Fort Johnson Road Charleston, South Carolina 29412
ABSTRACT An investigation was conducted into the deaths of more than 220 bottlenose dolphins (Tursiops truncatus) that occurred within the coastal bay ecosystem of mid-Texas between January and May 1992. The high mortality rate was unusual in that it was limited to a relatively small geographical area, occurred primarily within an inshore bay system separated from the Gulf of Mexico by barrier islands, and coincided with deaths of other taxa including birds and fish. Factors examined to determine the potential causes of the dolphin mortalities included microbial pathogens, natural biotoxins, industrial pollutants, other environmental contaminants, and direct human interactions. Emphasis was placed on nonpoint source pesticide runoff from agricultural areas, which had resulted from record rainfall that occurred during the period of increased mortality. Analytical results from sediment, water, and biota indicated that biotoxins, trace metals, and industrial chemical contamination were not likely causative factors in this mortality event. Elevated concentrations of pesticides (atrazine and aldicarb) were detected in surface water samples from bays within the region, and bay salinities were reduced to
