During 2005, program staff members were called upon to perform follow-up monitoring of 12 rough-toothed dolphins released after rehabilitation. Three of these were the survivors of a mass stranding off Ft. Pierce, Florida, in August 2004, rehabilitated by Mote Marine Laboratory’s Dolphin and Whale Hospital. The other nine were rehabilitated by the Marine Mammal Conservancy (MMC), following a mass stranding in the Florida Keys in March 2005, and were released as a group of seven and a subsequent pair of animals, due to differences in recovery times.

Mote’s dolphins were released off Ft. Pierce in March, 2005. They were tracked via satellite-linked radio transmitters as they made their way to the northeast in the Atlantic Ocean (see map below). Transmissions were received over periods of three to 23 days, and all available data indicate that the animals were doing well throughout the period of contact.

Two of the seven MMC dolphins released in May carried satellite-linked transmitters, and the other five carried VHF tracking transmitters only. They were released off the Keys, and were tracked for 31 to 38 days. After an initial period of apparent disorientation in the shallow waters west of Andros Island in the Bahamas, they continued to the east, cut north through Crooked Island Passage, and paralleled the West Indies. The last signal placed them northeast of the Lesser Antilles, with no indication of any health difficulties.

Two of the seven MMC dolphins released in May carried satellite-linked transmitters, and the other five carried VHF tracking transmitters only. They were released off the Keys, and were tracked for 31 to 38 days. After an initial period of apparent disorientation in the shallow waters west of Andros Island in the Bahamas, they continued to the east, cut north through Crooked Island Passage, and paralleled the West Indies. The last signal placed them northeast of the Lesser Antilles, with no indication of any health difficulties.

The two MMC dolphins remaining from the March stranding were released in September. Both received satellite-linked transmitters, and were released east of the Florida Keys. Tracking was performed over a period of two weeks, and the animals proceeded south to a deep trench close to the north coast of Cuba. The premature loss of contact was believed to be due to release of the tags from attachment pin breakage, a design feature for protecting the dolphins from entanglement. The attachment pins may not have been sufficiently strong to weather the heavy seas associated with Hurricane Rita as it passed over the dolphins.

The fact that these three groups of dolphins, along with another group from the March 2005 mass stranding released by another organization, followed different paths once released is interesting, and difficult to interpret. In all three cases described above there were no immediately obvious indications of any animal performance problems at the time of last transmission, suggesting that the rehabilitation programs had been successful.

Post-release monitoring is a service for which the SDRP is now contracted by NOAA Fisheries, and we expect to be involved in a number of release projects as programs at a variety of facilities in the southeast have become more successful in treating stranded dolphins.