SRIKAKULAM: A spike in the number of whales getting washed ashore on the eastern sea coast is possibly an indicator of the high pollution in these waters, experts said.
In this district of Andhra Pradesh, two whale deaths were reported in May. The carcass of a baleen whale washed up on the beach at Akkupalli village in Vajrapukotturu mandal on the morning of May 8. A fortnight later, another 40-ft whale was found dead on the beach near Yerramukkam village in Sompeta mandal.
While these deaths were not beachings, but deaths out at sea, perhaps due to a collision with a passing ship. Both carcasses reached the beach in a partially decomposed state. In January this year, carcasses of no less than 38 baleen whales were washed ashore near the Tiruchendur beach in Tamil Nadu while more than 250 were stranded in shallow waters.
Explaining the whales' behaviour, the head of the Zoology Department at Andhra University, U Shameem, said whales at times move into sea waters polluted with industrial chemicals. These are zones deficient in the whales' staple food, krill, and in oxygen. And since whales do not abandon their dead, mass beaching are often the result.
The Tamil Nadu incident was typical of this behavious, she said. Although volunteers tried to guide the whales back into the sea, they would just not go. Experts also say the waters off the eastern coast, particularly off Vizag, have busy shipping routes, and there is every possibility of a whale bumping into a ship and getting injured.
"Whales are gregarious by nature. They swim in groups with the leader showing them the direction. Sometimes, when a whale gets injured, it gets separated from the group, and becomes disoriented and may stray into shallow water," said Sankara Rao, additional director of fisheries, Hyderabad.
Shallow waters are dangerous towhales. "Whales put themselves at risk when they stray into shallow waters, because there is less oxygen there. They can die of hypoxia," said Palasa fisheries development officer Shravani Kumari. Whales usually foray into shallow waters in summer due to the lack of feed in the deep sea, said Srikakulam fisheries deputy director Yaqub Basha.
"They can't stand warmer waters and high pollution. They suffer hypoxia, resulting in their death."
(With inputs by Sri Lakshmi Muttevi from Vizag)