The International Rescue, Rehabilitation and Post-Release Monitoring of a Yearling Long-Beaked Common Dolphin (Delphinus capensis)
An estimated 1-year-old, male, long-beaked, common dolphin (Delphinus capensis) stranded approximately 0.5 mile south of the U.S. border. Local responders requested the assistance of SeaWorld San Diego and following emergency consultation with the NOAA-NMFS, the dolphin was imported into US under section 109(h)(2) of the MMPA.
The dolphin weighed 25 kg and measured 140 cm. He presented with full body tremors, elevated respiratory rate, diarrhea, an abscess adjacent to the right external auditory opening and leftward scoliosis. The dolphin was treated for dehydration, muscle contracture/stranding myopathy, non-specific infection, and abscessation. He was supported with a buoyancy device due to severe listing and the inability to swim. AEPs indicated that his auditory system was functional. An MRI showed no evidence of domoic acid toxicity, but extension of abscess was noted near the right ear. The dolphin showed progressive improvement and started swimming independently after 10 days of treatment and physical therapy. All clinical signs eventually resolved and a peak weight of 31 kg was attained after 8 weeks of rehabilitation.
At one year of age, small cetaceans are likely nutritionally independent but may still be socially dependent on their dam. Because of his young age, it was deemed necessary that the dolphin demonstrate the ability to forage and hunt. Initial live fish feeding trials failed. However, due to continued efforts, the dolphin started accepting live fish when introduced along with frozen-thawed fish into the pool after 12 weeks of rehabilitation.
The dolphin was microchipped, freeze-branded and fitted with a satellite tag and released into a pod of conspecifics. Nineteen days following release the satellite signal was lost 250 nm offshore. While the outcome of this dolphin is unclear, valuable lessons were learned regarding the medical management, food item conditioning and tagging of weanling small cetaceans.
The authors would like to thank the SeaWorld San Diego Rescue team and the Zoological staff members for their help and support with the management of this case. We thank NMFS, especially Sarah Wilkin, for their assistance with the emergency import and later efforts in contacting Mexican authorities and Drs. Randy Wells and John Durban for their recommendations on tag selection. The hearing test and MRI were performed by Dr. Dorian Hauser (NMMF) and Dr. Miriam Scadeng (UCSD) respectively.
* Presenting author