SPOT tags use GPS based satellite telemetry and transmit data whenever the dorsal fin breaks the surface of the water. SPOT tags are manually attached by drilling through the dorsal fin, which requires the shark to be lifted from the water so that it may be operated on. These tracks may have root mean square errors of 0.89- of longitude and 1.47- of latitude. Tracks are determined from the ARGOS positioning system using data collected on light levels, which can then compare sunrise and sunset and estimated location.
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In order to access the full archival record of the tag the tag needs to be retrieved. PAT tags remain attached for a predetermined period (days/months) before automatically “popping-off”, floating to the surface and transmitting a summary of data collected via satellite. White sharks are lured close to a research vessel and the tag is attached below the dorsal fin using a tagging pole as the free-swimming animal passes the vessel. For white sharks ( Carcharodon carcharias) specifically, two types of satellite tag have been used: Pop-off Archival Tags (PAT) and Smart Position Only/Temperature transmitting Tags (SPOT) – PAT tags are considered to be low stress generating and a relatively non-invasive method of satellite tagging. The last decade of pelagic marine animal research has shown that satellite telemetry has greatly enhanced the documentation of these movements –.
Transmissions from satellite tags can not penetrate the water's surface, and acoustic telemetry requires receivers to be within a limited range to pick up tag transmission. Monitoring the large scale movements of pelagic animals is logistically difficult due to the vast spatial ranges they transverse.