Preliminary Observations on Implantation and Efficacy of Internal Acoustic Tags in Loggerhead Sea Turtles (Caretta caretta) and External Acoustic Tags in Leatherback Sea Turtles (Dermochelys coriacea)
Abstract
Acoustic tags can reveal the location of aquatic animals for long periods of time, with some tags having battery life of up to ten years.1–7 Acoustic tags have been attached to the shell of some aquatic turtle species, but premature detachment has been problematic in some cases presumably due to growth of the shell or physical dislocation of the tag during breeding interactions.1,6,7 In other taxa, surgical implantation of acoustic tags has been successful, with long periods of tag detection.2–5 In this study, acoustic tags (Innovasea V13-1H) were surgically implanted subcutaneously in the pre-femoral space of four loggerhead sea turtles that had been rehabilitated after cold-stunning. Under general and local anesthesia, a scalpel incision was made, followed by blunt dissection, tag insertion, and two-layer closure. Incision healing was excellent. All tags were detectable in a captive setting using a hydrophone. Upon release, tags were detected numerous times by receivers off the coast of Massachusetts. Under local anesthesia, external acoustic tags (Innovasea V16-4H) were attached through two osteotomy sites on the lateral ventral pygal region of the carapace of six leatherback turtles after disentanglement from fishing gear or stranding on shore. Tags were detected numerous times off the coast of Massachusetts, Florida, Georgia, and South Carolina. To the authors knowledge, this work represents the first internal acoustic tagging for any turtle species, and the first use of acoustic tags for adult and subadult leatherback turtles. Internal acoustic tagging may provide a more affordable and longer lasting alternative to satellite tags.
Acknowledgments
Acoustic tagging was conducted under authority of United States Fish and Wildlife Service Permit ES69328D-1 and National Marine Fisheries Service Permit 21301-01. We thank Megan Winton, Greg Skomal, Bill Hoffman, Joy Young, Jim Whittington, Chris Kalinowsky, Bryan Franks, and Caroline Collatos for sharing tag detection data from their receivers. We thank the staff and volunteers of Massachusetts Audubon Wellfleet Bay Sanctuary and the International Fund for Animal Welfare for recovery and transportation of stranded turtles. The staff of the Center for Coastal Studies, Northeast Fisheries Science Center, United States Coast Guard, Coonamessett Farm Foundation, Town of Dennis, Town of Yarmouth, and Town of Plymouth harbor masters, Mark Leach, Ernie Eldredge, and Robert Martin provided access to entangled leatherback turtles. Abby Gelb, Kate Sampson, Brian Stacy, and Connie Merigo facilitated authorization for internal tagging. Susan Barco provided essential pilot data regarding internal acoustic tag detection in loggerhead turtle cadavers.
Literature Cited
1. Barco SG, GG Lockhart. 2017. Turtle Tagging and Tracking in Chesapeake Bay and Coastal Waters of Virginia: Final Contract Report. Draft Final Report. Prepared for U.S. Fleet Forces Command. Submitted to Naval Facilities Engineering Command Atlantic, Norfolk, Virginia, under Contract No. N62470-10-3011, Task Order 50, issued to HDR Inc., Virginia Beach, Virginia. February 2017. 56pp.
2. Bino G, Kingsford RT, Grant T, Taylor MD, Vogelnest L. 2018. Use of implanted acoustic tags to assess platypus movement behaviour across spatial and temporal scales. Sci Rep 8(1):5117.
3. Breece MW, Fox DA, Oliver MJ. 2018. Environmental drivers of adult Atlantic sturgeon movement and residency in the Delaware Bay. Mar Coast Fish 10(2):269–80.
4. Horning M, Haulena M, Tuomi PA, Mellish JA, Goertz CE, Woodie K, Berngartt RK, Johnson S, Shuert CR, Walker KA, Skinner JP. 2017. Best practice recommendations for the use of fully implanted telemetry devices in pinnipeds. Anim Biotelemetry 5(1):13.
5. Kneebone J, Chisholm J, Skomal G. 2014. Movement patterns of juvenile sand tigers (Carcharias taurus) along the east coast of the USA. Mar Biol 161(5):1149–63.
6. Micheli-Campbell MA, Connell MJ, Dwyer RG, Franklin CE, Fry B, Kennard MJ, Tao J, Campbell HA. 2017. Identifying critical habitat for freshwater turtles: integrating long-term monitoring tools to enhance conservation and management. Biodivers Conserv 26(7):1675–88.
7. Smith BJ, Selby TH, Cherkiss MS, Crowder AG, Hillis-Starr Z, Pollock CG, Hart KM. 2019. Acoustic tag retention rate varies between juvenile green and hawksbill sea turtles. Anim Biotelemetry 7(1):1–8.