For the first time in India, a whale shark has been tagged with a ‘satellite collar’ to track the migration routes, behaviour and ecological preferences of this member of the largest fish species in the world.
The satellite tag was put on the fish last week by a team of researchers from the Whale Shark Conservation Project, a joint venture of the Gujarat Forest Department and Wildlife Trust of India (WTI).
According to WTI Assistant Field Officer, Manoj Matwal, another whale shark will be tagged by mid-May.
“The first set of data received indicated that the tagged whale shark, a 6.5 m long male rescued off the Gujarat coast, had reached the coast of Maharashtra moving southward,” Mr. Matwal told PTI.
“We plan to install a similar satellite tag on another whale shark, preferably a female, by mid-May as after that they are not seen off the Gujarat coast,” he said.
“For the second tagging, we are exploring the sea near Veraval and Sutrapada in Junagadh district where the spotting (of whale shark) has been good.”
Satellite-tagging is the latest initiative under the Whale Shark Conservation Project. Earlier there have been efforts to do photo-identification, genetic analysis and visual tagging of whale sharks in India.
“The satellite tag, which is a marine equivalent of a satellite collar, was attached to the caudal fin of the fish.
Data from the tag is transmitted to the satellite every time the fish surfaces,” Mr. Matwal said.
“This tag is expected to last for about six months and give us data related to movement of the fish, its preference in water temperature, diurnal and nocturnal activities and swimming patterns between different layers of water.”
The success of tagging was confirmed after receiving the first signal 68 hours after the tag was fixed.
“The signal was received 250 km off the coast of Mumbai, revealing that it had travelled southward,” Mr. Matwal said.
Over the coming months, researchers would be closely following the movement patterns of the whale shark.
During the tagging operation, WTI also collected a tissue sample of the fish for genetic analysis.
The whale shark was listed under Schedule I of the Indian Wildlife (Protection) Act in 2001, according it the highest level of protection.
Whale shark is the largest fish species in the world with a flattened head, and a wide mouth positioned at the tip of the snout that stretches almost as wide as the body. The creatures are greyish, bluish or brownish above, with an upper surface pattern of creamy white spots between pale, vertical and horizontal stripes.
Whale sharks were once hunted off the Gujarat coast for its liver oil, which was used to water-proof boats. But after initiation of Whale Shark Conservation Project in 2008, the local fishermen have been made aware of the importance of the fish, and they now participate in conservation activities.