They indicate the size ,breed and location of the Sharks.
This is a Project being done in Australia.
About 300 Sharks have been fixed with Transmitters and these signals are picked up by a Computer which Tweets to Twitter at Surf Life Saving Western Australia’s (SLSWA) Twitter feed.
Western Australia is now the world’s deadliest place for shark attacks. Surfer Chris Boyd, 35, was killed in November and was the sixth person to die in the region in just two years.
Authorities in the state have patrolled beaches using helicopters and boats for years, but the recent spate of attacks has prompted the local government to look at new ways of trying to prevent incidents.
Ministers have just agreed to a controversial scheme allowing professional fishermen to kill sharks larger than three metres found in certain zones which are used by surfers and beach goers.
And bait will be put out one kilometre off shore to attract and catch sharks during the summer.
It is a move that has angered environmentalists.