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Open Access Highly Accessed Methodology article

Intraperitoneal implantation of life-long telemetry transmitters in otariids

Markus Horning1*, Martin Haulena25, Pamela A Tuomi3 and Jo-Ann E Mellish34

Author Affiliations

1 Department of Fisheries and Wildlife, Marine Mammal Institute, Oregon State University, Newport, OR 97365, USA

2 The Marine Mammal Center, 1065 Fort Cronkhite, Sausalito, CA 94965, USA

3 Alaska Sea Life Center, 301 Railway Ave, Seward, AK 99664, USA

4 School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, AK 99775, USA

5 Vancouver Aquarium, PO Box 3232, Vancouver, BC V6B3X8, Canada

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BMC Veterinary Research 2008, 4:51  doi:10.1186/1746-6148-4-51

Published: 10 December 2008



Pinnipeds, including many endangered and declining species, are inaccessible and difficult to monitor for extended periods using externally attached telemetry devices that are shed during the annual molt. Archival satellite transmitters were implanted intraperitoneally into four rehabilitated California sea lions (Zalophus californianus) and 15 wild juvenile Steller sea lions (Eumetopias jubatus) to determine the viability of this surgical technique for the deployment of long-term telemetry devices in otariids. The life history transmitters record information throughout the life of the host and transmit data to orbiting satellites after extrusion following death of the host.


Surgeries were performed under isoflurane anesthesia and single (n = 4) or dual (n = 15) transmitters were inserted into the ventrocaudal abdominal cavity via an 8.5 to 12 cm incision along the ventral midline between the umbilicus and pubic symphysis or preputial opening. Surgeries lasted 90 minutes (SD = 8) for the 19 sea lions. All animals recovered well and were released into the wild after extended monitoring periods from 27 to 69 days at two captive animal facilities. Minimum post-implant survival was determined via post-release tracking using externally attached satellite transmitters or via opportunistic re-sighting for mean durations of 73.7 days (SE = 9.0, Z. californianus) and 223.6 days (SE = 71.5, E. jubatus).


The low morbidity and zero mortality encountered during captive observation and post-release tracking periods confirm the viability of this surgical technique for the implantation of long-term telemetry devices in otariids.