Transmission from tracking device on whale shark shows where the animal travelled for 33 days
Emmanuelle Landais Gulfnews 15 Jun 10;
Dubai: The satellite tag of a baby female whale shark released back into the wild by a Dubai hotel's marine department earlier this year has popped up showing where she travelled for 33 days.
Sammy the whale shark was placed in Atlantis, The Palm in August 2008 and released in March this year.
No photos of the secret nighttime release were issued by the hotel but the tag's information has now been mapped by Mote Marine Laboratory scientists in the United States.
Scientists have satellite-tagged 30 other whale sharks in the wild. Sammy, at 4.6-metres long, is believed to be the first whale shark tracked via satellite tag in the Arabian Gulf.
Check out the tracking map for Sammy
She showed normal swimming behavior during her month-long tracking period, including diving and surfacing regularly.
Her satellite tag, programmed to "pop up" and float to the surface 100 days after her tag and release, detached two months early on April 20.
It is unknown why this happened but not unusual for satellite tags to come off early.
"Even though the whale shark's tag detached early, we have put together a good-quality picture of her travels for her first month after release," said Dr. Robert Hueter, Director of Mote's Center for Shark Research and leader of the tracking project.
"After Atlantis staff tagged and released her off Dubai, the whale shark took a mostly westward path through the Arabian Gulf, traveling south of Iran and then curving southward to waters off the coast of Qatar, ending up about 348 km west of her starting point," Hueter said.
The tag reveals that between March 18 and April 20 Sammy experienced temperatures of between 22.6 and 26.8 degrees Celcius, came to the surface at least once each day, and dove as deep as 72 metres. The Arabian Gulf's average depth is 50 metres and its maximum depth is 90 metres.
The satellite tag stored location data based on sunlight levels. Mote scientists analysed the raw data, looking at dawn and dusk times along with day length to estimate the shark's position.
Those sunlight conditions change with latitude and longitude, allowing the scientists to estimate the shark's location over the course of the track.
"That's normal behaviour similar to what we've observed in other whale sharks," Hueter said.
"Atlantis is thrilled that Mote Marine Laboratory has been able to track the whale shark's progress and share the collected data so the entire whale shark community can continue to learn from her," said Steve Kaiser, Vice President of Marine Science and Engineering at Atlantis, The Palm in Dubai, which provided funding for the tag, satellite transmission, and data analysis.
The Atlantis team bought a total of five tags from Mote in 2007.
