Telemetry on Wild Sea Lions: Surgeries

surgeryLHX1 tags are relatively small compared the size of a Steller sea lion. Each tag accounts for less than 0.1% (one tenth of one percent) of the typical mass (weight) of a one year old sea lion. This is substantially less than the recommended limit of 3% of an animal’s mass. Using full gas anesthesia and many of the same aseptic procedures as for human surgeries, a marine mammal veterinarian surgically implants two sterilized tags inside the body cavity of the sea lion near the abdomen. The tags are specially coated with an inert material used in some human biomedical implants that prevents body tissue from growing around and sticking to it. This is important, since the coating allows the tag to freely move around the abdomen and come out of the body easily if a predator dismembers an animal. Each sea lion gets two tags to maximize the likelihood that the scientists will receive data if the animal dies (see the LHX Tags page for more information). The first 15 animals that received LHX implants in 2005 through 2008 were monitored for four to eight weeks after surgery to monitor healing of the incision as well as their general health and well being. Results from this initial monitoring showed that normal wound healing is completed within 6 weeks or less and that the surgery is well tolerated. Now animals are monitored for only 1-2 weeks before receiving a final checkup and being released back into the wild.

The surgical protocol we used to implant 1st generation LHX1 tags is described in this freely downloadable 2008 publication:

Horning M, Haulena M, Tuomi P, Mellish J (2008) Intraperitoneal implantation of life-long telemetry transmitters in otariids. BMC Veterinary Research 2008 4: 51.

The following paper (also freely downloadable as an Open Access paper) describes the updated surgeries we used ti omplant the much smaller 2nd generation LHX2 tags into rehabilitated harbor seal pups at the Vancouver Aquarium:

Horning M, Haulena M, Rosenberg JF, Nordstrom C (2017) Intraperitoneal implantation of life-long telemetry transmitters in three rehabilitated harbor seal pups. BMC Veterinary Research 13: 139.

A brief summary of this paper written for the general public can be found here as part of our new ASLC science blog: 60 North Science.

Also of interest should be the following Open Access paper in which we synthesize our own experiences over the past 15 years, as well as those of colleagues that also use implanted telemetry devices, for a set of best practice recommendation son how to use implanted devices in pinnipeds:

Horning M, Haulena M, Tuomi PA, Mellish JE, Goertz CE, Woodie K, Berngartt RK, Johnson S, Shuert CR, Walker KA, Skinner JP, Boveng PL (2017) Best practice recommendations for the use of fully implanted telemetry devices in pinnipeds. Animal Biotelemetry 5:13.

You can also read a brief summary of this paper written for the general public, in our new ASLC science blog: 60 North Science.