Abstract

A mass stranding of 30 Fraser's dolphins, Lagen delphis hosei, occurred along the southwest coast of Florida on 13 July 1994. Responding to this event was the Mote Marine Laboratory Stranding Team, in conjunction with the Fort Myers Stranding Group and the Florida Department of Environmental Protection.

In general, the dolphins appeared robust and in good body condition. Although "stranded", the dolphins were not immobilized. Most were floating with only their heads aground either on sandbars located on either side of a narrow inlet, or they were actively milling in the inlet. Many of the animals repeatedly moved of their own volition between the open water of the inlet and the shore. Later, during the release effort, the importance of maintaining the intact school in this species was apparent. The dolphins refused to be herded under a nearby bridge until a majority was physically walked as a unit under this perceived obstacle. The unescorted dolphins followed in close proximity.

This stranding provided an opportunity to collect blood samples for health profiles from 23 live, active juvenile and adult individuals (4 males: 19 females) of a species which has rarely been kept in oceanaria or treated in rehabilitation centers. On the beach, the 27 surviving dolphins were examined, hydrated, roto-tagged and later released as a group. Chemistry (Table 1) and hematology values (Table 2) are generally similar to other odontocetes including T. truncates (Asper et al., 1990; Bossart and Dierauf, 1990; Rhinehart et al., 1991, 1992). However, mean RBC (4.86 million/cmm), HGB (22.1 g/dl), and HCT (60.3 A) values are higher than in free-ranging T. truncates (Asper et al., 1990; Rhinehart et al., 1991, 1992). Liver function tests and creatinine levels appear to be elevated within this group, and there is hematological evidence of fasting prior to stranding (Bossart and Dierauf, 1990). Subsequent antibody testing revealed that 9 of 23 dolphins had significant titers (>1:100) to the dolphin morbillivirus (Duignan ef al., in press), but no external signs of disease were evident. These blood profile data are offered as a first compilation of reference values for this species.

References

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