Tracked over 200 days, a whale shark’s migration from Gujarat to Somalia

In what they termed as the longest migratory movement of a whale shark ever recorded in the Indian subcontinent, scientists from Wildlife Trust of India (WTI) successfully tracked a female Whale Shark for over 200 days, now found off the Somalia coast. The marine creature has covered a distance of 5,500 kms (2,970 nautical miles) from Sutrapada, Gujarat, satellite data revealed.

The satellite monitoring was carried out under the Whale Shark Conservation Project run by WTI and Gujarat Forest Department (GFD) and funded by Tata Chemicals Ltd.

On December 30, 2016, Herabhai, a fisherman from the Sutrapada village in Gir Somnath district alerted the WTI field team in Gujarat that a whale shark was entangled in his fishing net approximately four nautical miles off the coast. Thirty minutes later, WTI field staff and GFD offices reached the spot. They found the 18-20 feet whale shark to be healthy. After collecting tissue samples, they tethered a 15-cm long transmitter to its dorsal fin.

This was the seventh time the team had attempted to monitor the elusive creatures of whom not much is known in terms of migration. During earlier attempts, the satellite tag would usually face technical failures.

The reasons behind occurrence of these creatures off Gujarat coast is still hazy. “Our larger assumption is that they come here to breed because baby whale sharks cannot swim long distance, so there is a high chance they are born here,” said said Sajan John, manager and head of marine conservation project, WTI.

“Various factors lead to monitoring failures. There are fishing pressures, they dive too deep and thus the satellite gets detached,” said Sajan John, manager and head of marine conservation project, WTI. Explaining the data collecting and monitoring, he added, “There is a lot of back-end work involved in tracking the location. There is a 24-hour lag in obtaining the location. The satellites pick up the location and relay to web applications managed by ARGOS System in Largo, Maryland and Toulouse, France. Additionally, the tag also collects water temperature, which contributes in studying the migratory patterns of the vulnerable category of fish.

The global scientific community has termed it as a milestone. “The efforts of the WTI team have provided a new milestone for our understanding of whale sharks in the Indian Ocean”, said Dr Mark Meekan of the Australian Institute of Marine Science. “With their 200+ days of tracking, the final piece in the jigsaw puzzle of whale shark migration in the region is starting to fall into place. It’s a great achievement for both conservation and shark science,” he added.

The satellites pick up the location and relay to web applications managed by ARGOS System in Largo, Maryland and Talouse, France. Additionally, the tag also collects water temperature, which contributes in studying the migratory patterns of the endangered marine creatures.

DNA INDIA

Related Post

Optimization WordPress Plugins & Solutions by W3 EDGE
%d bloggers like this: