Abstract

Development of release criteria and evaluation of post-release survival requires multi-year post-release monitoring of rehabilitated marine mammals. A novel satellite-linked Life History Transmitter implanted into the peritoneal cavity has been previously evaluated for safety and efficacy in California (Zalophus californianus) and Steller (Eumetopias jubatus) sea lions. A new generation of smaller implants (33-mm diameter x 95-mm length, 57 g) now allows their use in smaller marine mammals. Three recently weaned female harbor seal (Phoca vitulina) pups (14.3 to 17.3 kg) undergoing rehabilitation were anesthetized and aseptic technique was used to surgically implant the transmitters through a ventral midline incision. Multilayer closures with absorbable monofilament sutures were used, and the animals were closely monitored for 80 days prior to release. Haematology, fibrinogen, haptoglobins and serum chemistry were monitored regularly and showed mild to moderate transient leukocytosis after the procedure. Moderate suture reaction was noted in animals with external skin sutures while the single animal without external sutures showed no skin reaction. Incision sites were healed, and there was no indication of inflammation at the time of release. Each animal was fitted with an external satellite-linked transmitter glued to the pelage of the head for post-release monitoring. All three animals have been followed for 114 days after release and 194 days after surgery at the time of this abstract, displaying expected movement patterns for seals of this age and species. This is the first report of the successful implantation of intra-abdominal instruments in phocid seals.

* Presenting author