Interventions for dolphins in life-threatening situations are increasing in frequency in the southeastern U.S., involving rescues for on-site disentanglements and releases, translocations and releases, or rescues or strandings followed by rehabilitation and release. Follow-up monitoring remains a crucial component of interventions. Information on the success of the intervention, as judged by the survival and behavior of the animals post-release, can guide decisions about further intervention if the animal fails to thrive in the wild, and can inform future efforts with other animals under similar circumstances. Such information is increasingly important as interventions are being considered among the possible restoration options in response to the Deepwater Horizon oil spill and other environmental contaminant situations.
The Sarasota Dolphin Research Program provides follow-up monitoring services to the members of the national marine mammal stranding network through a grant from NOAA’s John H. Prescott Marine Mammal Rescue Assistance Grant Program. We maintain a supply of satellite-linked tags and tagging and tracking supplies, and provide tracking services to organizations who request them. During 2016, we provided tags to a number of organizations for possible deployment, and these were ultimately deployed in four cases, involving bottlenose dolphins and pygmy killer whales.
On January 19th, a young female bottlenose dolphin, given the name Lil’ Rae, was rescued by NOAA from a small canal near Bay St. Louis, Mississippi, and tagged and translocated to nearby Gulf of Mexico waters. She moved through a fairly limited area, in Bay St. Louis and adjacent Gulf waters, for about two months before her carcass was recovered on March 23rd at the mouth of the Jourdan River in the northwestern corner of Bay St. Louis. Final conclusions from necropsy are pending.
On March 25th, another young female bottlenose dolphin, given the name Alli, was rescued by NOAA and SeaWorld from a lake off the Perdido River in Alabama. She was tagged and translocated to Perdido Bay. She moved through a fairly limited range, including Perdido and Wolf Bays, until her carcass was recovered on June 18th. Final conclusions from necropsy are pending.
On April 28th, a young male bottlenose dolphin, given the name Octavius, that had undergone rehabilitation at Audubon Aquarium of the Americas since his stranding in October during a storm associated with the remnants of Hurricane Patricia, was returned to Barataria Bay, Louisiana for release. I traveled to Barataria Bay to perform the tagging and initial tracking, then continued remote tracking. The dolphin’s tag provided location data until June 5th, showing him moving through western Barataria Bay, Timbalier Bay, and Terrebonne Bay. On June 7th he was observed and photographed by NOAA staff with the tag intact, indicating a tag electronics failure issue. Occasional signals without location data were received through August 13th, suggesting that he was still alive at least 3.5 months post-release.
On July 11th, the Institute for Marine Mammal Studies in Mississippi released two male pygmy killer whales that had undergone rehabilitation since their stranding on September 1st, 2015, near Waveland, MS. They were tagged and released off the edge of the continental shelf south of Mississippi. One was tracked through July 26th and the other through October 7th, until maximum dive depths declined and signals ceased. They moved primarily along the shelf edge south of Louisiana, through the Mississippi Canyon and Houma Valley. Their deepest dives exceeded 350 m, and their longest dives exceeded nine minutes.
This article appeared on page 26-27 of the 2017 SDRP Annual Report, Nicks n Notches.