Patterns of bottlenose dolphin, Tursiops truncatus, strandings in Texas

During the spring of 1994, large numbers of bottlenose dolphins, Tursiops truncatus, washed ashore along the upper Texas coast. The majority of these carcasses were in an advanced state of decomposition, indicating that death had occurred some time earlier, possibly offshore. Despite intensive efforts to determine the cause of death by traditional pathological examinations, no conclusions could be drawn. Eventually, through the use of polymerase chain reaction (PCR) techniques, the Armed Forces Institute of Pathology was able to determine that a large proportion of the animals had an active morbillivirus infection and that this was likely the cause of death. Compared to normal years, increased numbers of dead dolphins began washing up on beaches during December 1993, peaking in March and April 1994 when a total of 171 dolphins were retrieved and continuing through May 1994. Of this total, 89% were retrieved between Matagorda Bay and the Louisiana state line. The actual impact on thecoastal bottlenose dolphin population may never be known because of a lack of robustness in the population estimates, however, ongoing surveys of the resident populations in Galveston, Matagorda, and Corpus Christi Bays do not indicate any decline in local abundance