Leatherback Tagging Project Completed Successfully

 Marine Turtle Research Program (MTRP)
The 2007 field effort for in-water capture and sampling of leatherback turtles off the central California coast concluded on October 2. Scott Benson led this 7-week effort with MTRP staff (Erin LaCasella, Peter Dutton, Tomo Eguchi, Mike James), contractors and partners. This year was the most productive field sampling season in the history of the project. Twelve leatherbacks were captured in neritic waters between Point Montara and Pigeon Point (San Mateo County) for blood and DNA samples, and 7 of the turtles received satellite-linked transmitters as part of phase I of the Leatherback Use of Temperate Habitat (LUTH) project. It is expected that some of the tagged turtles will return to waters off California next year to guide the LUTH sampling and survey efforts. In addition to the capture effort, 9 short-term (1-116 hours) deployments of VHF transmitters combined with time-depth-temperature recorders were accomplished without capture, via a pole-mounted small suction cup apparatus, to provide behavior data at the coastal foraging ground. For the first time, suction cup tags were deployed over multiple days and recovered 1-7 days later with the help of the aerial tracking team. Concurrent aerial and shipboard surveys provided additional distribution and ecosystem data, including size and composition of jellyfish prey and oceanographic sampling. The 2007 season contrasted greatly to the 2006 season when leatherbacks and jellyfish were absent from the study area. Combined results from this and previous field studies will be useful for determining abiotic and biotic conditions that are required for presence of leatherback turtles in the nearshore marine environment. Observations from the field can be viewed at http://www.topp.org/blog/scottbenson.  The SWC-MMTD website will be updated with video clip pieces showing new field techniques.