KERALA

DNA codes identify beached whale

Special Correspondent

Scientists say it is Bryde’s whale of the Balaenoptera edeni species

Thiruvananthapuram: DNA tests of samples taken from the putrefied carcass of a marine animal washed ashore at the Poonthura beach here on June 26 have revealed that it was a Bryde’s whale (Balaenoptera edeni).

A. Bijukumar of the Department of Aquatic Biology and Fisheries, University of Kerala, who collaborated with Sanil George of the Rajiv Gandhi Centre for Biotechnology to identify the species, said the specimen could not be identified on visual examination because of its damaged upper jaw and putrefied carcass.

Going by the baleen plates suspended from the upper jaw and the long pleats on the lower profile of the head, scientists who examined the carcass on location confirmed it as a whale in the genus Balaenoptera (Byrde’s whale, fin whale and blue whale belong to this group). But the dented upper jaw made identification difficult.

“Further examination of the specimen was difficult because of the public outcry to bury the foul-smelling carcass. We decided to use DNA barcoding to confirm the identity of the specimen, as marine mammals are rare and are included in the Schedule I of Indian Wildlife (Protection) Act. The WWF of India Kerala State Office and the Kerala Forests and Wildlife Department were keen to record the taxonomic identity of the specimen, as whales were of conservation value,” Mr. Bijukumar said.

Barcoding

DNA barcoding is a standardised technique to discover, characterise, and distinguish species, and to assign unidentified individuals to species. It involves the use of a short DNA sequence like a bit of tissue from a living or dead organism.

The Marine Mammal Conservation Network of India ( >www.marinemammals.in), which maintains records of marine mammal sightings and stranding in the country from the year 1800, registers only one earlier stranding of Bryde’s whale in southwest coast of India.

Named after Norwegian consul to South Africa Johan Bryde, who helped set up the first whaling station in Durban, South Africa in 1908, this little-known species among baleen whales is distributed in the Pacific, Indian and Atlantic oceans, in warmer waters. The Bryde’s whale is included in Appendix I of Conservation of International Trade of Endangered Species of Flora and Fauna (CITES) and in Appendix II of the Convention on Migratory Species (CMS), and thus offered protection at international level.

The whale found in Thiruvananthapuram measured about 14 meters in length, the normal size of a Bryde’s whale, though pygmy forms have also been recorded.

The whales washed ashore and stranded on the beaches of India are often not properly identified due to the lack of taxonomic expertise locally and poor condition of the specimens. The IUCN Red List of endangered species classifies the Bryde’s whale as “Data Deficient” because there is insufficient information to determine the risk of extinction. The main threats to marine mammals are fishing-net entanglement, chemical pollution and noise pollution.

“A database is needed to assess the distribution and migratory nature of various species of whales that have inhabited the earth’s oceans for millions of years and are a vital part of the ocean’s ecosystem,” Mr. Bijukumar said.

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