The hump-backed mahseer is now ‘critically endangered’
The hump-backed mahseer, found in the waters of the Cauvery, has been added to the Red List as Critically Endangered
This tiger does not have stripes. But the hump-backed mahseer—a large freshwater fish also called the tiger of the water and found only in the Cauvery river basin (including Kerala’s Pambar, Kabini and Bhavani rivers)—is now “Critically Endangered”: more threatened than the tiger is, as per the International Union for Conservation of Nature’s Red List of Threatened Species. The fish is one of the 229 species added to the Red List last November; this update also reveals that the threat status of 12 other Indian species, including great hornbills, has increased.
The inclusion of the mahseer in the Red List, an inventory of the conservation status of the world’s species, was possible only once the fish got its scientific name last June—Tor remadevii—thanks to detailed research by Rajeev Raghavan (Kerala University of Fisheries and Ocean Studies, Kochi) and his Indian and international collaborators.
When Adrian Pinder of Bournemouth University and Raghavan began studying the mahseer in 2011, “it quickly became apparent that there was still widespread confusion about their taxonomy and the distribution ranges of individual species which are fundamental to assessing population status and conservation needs,” according to Pinder.
The team set this right: their assessment now recognises 16 species of mahseer in India. Now, securing the future of the hump-backed mahseer would depend on the strong willingness and cooperation of a range of stakeholders in three states—Kerala, Tamil Nadu and Karnataka—in the Cauvery, one of India’s most contested rivers, says Raghavan.
Five other species have also made it to threatened categories: two wild orchids, the Arabian scad (a marine fish) and two wild coffee species found only in a few localities in the Western Ghats.
While 31 species that were already in the Red List have been down-listed (since threats are not as significant as earlier thought or due to conservation efforts), the threat status of 12 species has increased. The great hornbill (found in India and southeast Asia) was earlier categorised as “Near Threatened”. It is now “Vulnerable” due to high hunting pressure coupled with habitat loss and deforestation, while the wreathed hornbill has moved from “Least Concern” to “Vulnerable”.
A lot of published literature including information on the status of the birds; habitats across Asia were incorporated into this assessment, said Aparajita Datta, senior scientist at the Nature Conservation Foundation and co-chair for the IUCN-SSC Hornbill Specialist Group, who was part of the assessment team.
“An interview-based occupancy survey we conducted in five states in north-east India in 2013-14 showed a decline in great hornbills,” she said. Their earlier survey revealed that the birds have been locally extirpated from several sites in the north-east.
Conservation managers use information from the Red List to understand threats to specific species and plan effective conservation strategies to improve the conservation status of individual or groups of species, said Craig Hilton-Taylor, head of the IUCN Red List.
For instance, it is thanks to its new IUCN status that Shoal (an international organisation working to conserve freshwater species) initiated ‘Project Mahseer’ last month along with other stakeholders to enable conservation action for the hump-backed mahseer, said Raghavan. The Red List is indeed being used in many developing countries including India as a standard to understand the conservation status of species, said Datta.
“There is an increase in conservation action, funding and research when a species is included in the List. But uplisting or downlisting species is a continuous process. The latter is seen as a sign of success so that should be the ultimate aim.”
