Conditioning Bottlenose Dolphins (Tursiops Truncatus Gilli) for Voluntary Diving Studies

The behavior and physiology of diving has been extensively studied in several species of pinnipeds and marine birds. Less is known about the diving adaptations of the most completely aquatic mammals, the cetaceans. Early investigations of the diving abilities of dolphins were conducted using forced dive conditions in the laboratory, resulting in extreme physiological responses. The investigative technique improved during the late 1960's and 70'2 when dolphins were trained for diving experiments in the open sea, providing initial data on the natural diving physiology of these animals. In the present study, two Pacific Bottlenose dolphins (Tursiops truncatus gilli) were trained to dive to specific depths and then return to station for fluke presentation allowing immediate post-dive blood sampling. The samples were analyzed for lactic acid content, providing an indication of anaerobic effort during the graded dives. A Time-Depth Recorder worn by the animals recorded dive profiles which allowed calculation of swimming speed, bottom time, and ascent/descent rates. Additional experiments conducted in the home pen involved training the animals to allow serial blood samples to be drawn during voluntary breath-holds, thus providing information on blood gas changes. Simultaneous heart rate measurements were made to verify that forced dive bradycardia did not occur. These studies demonstrate the value of conditioning voluntary responses for scientific investigation, and additional uses for 'medical' behaviors

Presented at the Annual Conference of The International Marine Animal Trainers Association, Freeport, Bahamas, Nov 92.