The tagged shark was within detection range, about 1,500 feet, for only a few minutes before apparently leaving the area, according to Brandt Kehoe of the Friends of the Elephant Seal. It was first detected at 6:13 p.m.
The buoy, deployed by researchers with Stanford University’s Hopkins Marine Station with the support of the Friends of the Elephant Seal, is one of four shark-monitoring devices placed near California elephant seal rookeries to find out if the predators are attracted to areas with high concentrations of elephant seals.
The shark tags send out a signal every two minutes. If they’re within 1,500 feet of a detector, the signal is rebroadcast to a satellite, which forwards the message to a ground station that, in turn, notifies researchers on the ground by email within seconds.
About 100 sharks have been tagged.
The Piedras Blancas elephant seal colony began in 1990. Currently, an estimated 17,000 seals use the beach some time during the year.