Methods
Husbandry
Live sea turtles are held in an indoor sea-turtle holding facility at the Virginia Institute of Marine Science (VIMS) in tanks suitable to the size of the individual turtle. They are bathed in filtered water from the York River estuary, with salinity kept within the normal range of the animal’s natural habitat. The water and air temperature of the facility is monitored and controlled. VIMS staff members are on call at all times in case of emergency and are alerted by an electronic warning system if environmental conditions within the facility exceed a pre-determined range. The Institutional Animal Care and Use Committee (IACUC) of the College of William and Mary inspects our facility on a regular basis, under the strict guidelines of NIH and the USDA. The VIMS facility is registered under the Animal Welfare Act, U.S.D.A. registration number: 52-R-002. Animals held for scientific research or rehabilitation may be concurrently held on educational display. Turtles are regularly fed live or freshly dead crabs and/or squid. Portion size is based on a turtle’s size and weight.
Holding Methods and Facilities
Stranded turtles are held on the deck of small fishing vessels for up to 2 hours for initial transport to the nearest landing. They are then transferred onto shore and held in the shade, usually in a small amount of water. Water is also periodically poured on the turtles to keep them cool. Turtles are transferred to the VIMS' permanent facility in the back of a fully shaded pick-up truck specially adapted for the safe transport of live sea turtles. Transit time is less than 2 hours. The turtles are accompanied by VIMS personnel trained in the care, handling, and transportation of sea turtles. This protocol has been followed for 20 years with no ill effects on any sea turtles handled. Dr. Robert George of Gloucester Veterinary Hospital is on call in the case of any emergency.
Tagging
VIMS researchers tag stranded turtles prior to release in order to study their movement, behavior, and population dynamics.
Flipper Tagging
We use Inconel flipper tags to identify sea turtles that are stranded or found swimming and feeding in the storage pound of a commercial poundnet. Each tag has a unique 3-letter/3-digit number and an address to contact if the tag is found. Tags are applied to the turtle's flipper with a crimping tool. We normally place the tag on the back edge of a front flipper, near the first large scale. If a turtle has a damaged or missing front flipper, tags may also be applied to a hind flipper. Inconel tags can remain on turtles for more than 10 years. Tagging data are studied at VIMS and also provided to the Archie Carr Center for Sea Turtle Research (ACCSTR) at the University of Florida. Mark-recapture activities occur year-round, with most tagging occurring between May and December.
PIT Tagging
Passive Integrated Transponder (PIT) tags are small, inert microprocessors sealed in glass that transmit a unique identification number to a hand-held reader. These are the same tags that are used to identify household pets. When the reader passes close to the tag, the tag is activated with a low-frequency radio signal and the identification number associated with the tag is transmitted to the reader. PIT tags are inserted into the shoulder muscles of sea turtles, under the scales, or between the digits of the front flipper. Unless the turtle incurs flipper damage, this is a relatively permanent form of tagging. All PIT tagging data are provided to ACCSTR. Mark-recapture activities occur year-round, with most tagging occurring between the months of May and December.
Satellite, Radio and Acoustic Tagging
Satellite and radio transmitters are used to track the at-sea movements of sea turtles. The tags transmit a signal when the turtles come to the surface to breathe. Satellite and radio transmitters are placed on the turtles’ carapace at the second vertebral scute. This location provides optimal transmission when a turtle surfaces. Prior to application, the scute is lightly sanded with 100-grit sandpaper and then cleaned with acetone. Quick setting marine epoxy is used to attach the transmitter to the turtle.
Acoustic transmitters are placed along the ninth and tenth marginal scute. Two holes are drilled in each marginal scute and the transmitter is secured into place using degradable wire and quick-drying marine epoxy. Satellite, radio, and acoustic tags are temporary tags. As turtles shed their scutes, tags are lost. The duration and location of our satellite telemetry study depends on how long each satellite tag transmits and where the turtles travel while tags are transmitting.