Fig. 3

Examples of optimal EDT configuration and attachments. a Australian sea lion adult female and 6-month-old pup at Kangaroo Island, South Australia, part of a research project investigating the ontogeny of diving and movement behavior and physiology [32]. The adult female is instrumented with (from head to tail) an Argos satellite transmitter (Telonics Inc., Mesa, AZ, USA), a Mk-6 depth and swim velocity data recorder (Wildlife Computers, Redmond, WA), and a VHF beacon (Lotek/Sirtrack, St. John’s, Canada). The pup is carrying a Mk-5 depth data recorder (Wildlife Computers) and a VHF beacon (Lotek/Sirtrack). 6-month-old pups were not instrumented with Argos transmitters because earlier observations indicated that they did not leave the colony until they were older, making the additional instrument unnecessary (Recommendations # 1, 3, and 4). The instruments were attached to the animals using a 2-part quick-setting epoxy, with a layer of neoprene and mesh between the tag and pelage to allow for easy removal during recapture (Recommendation # 9). Tags were attached in line along the dorsal surface to minimize disruption of laminar flow around the animal (Recommendation # 8). Photo © DP Costa, 2002, South Australian Department for Environment and Heritage permit #G24475-2. b Attachment of a SPOT Argos transmitter (Wildlife Computers, 72 × 54 × 24 mm, 119 g) to the head of an adult Pacific harbor seal in Oregon. The base of the tag was built up into a convex shape to conform to the curvature of the skull, and is then directly glued to the pelage surface with Loctite™ Type 422 ethyl-cyanoacrylate adhesive (Henkel Corp., Düsseldorf, Germany). No mesh is used to minimize the contact area to the tag footprint (Recommendation #9 and 10). This adhesive sets within 10–30 s, and may generate some heat in the process. An alternative that produces less reaction heat for work in warmer climate can be found in Loctite™ Type 4861 ethyl/butyl cyanoacrylate that cures within 60s without generating much heat in the process. Type 4861 remains flexible on curing. However, achieving proper curing can be challenging, and may be facilitated through the use of accelerants (water or acetone mist). This deployment was part of an investigation into the spatial behavior of harbor seals, their use of marine reserves, and environmental drivers of their movement [110]. The lightly sedated animal is being immobilized on a V-shaped restraint board during the attachment (Recommendation # 6). Photo © SM Steingass, 2015, NMFS #16691