Mahseer fish, found only in Cauvery basin, is on the brink of extinction, going by a joint study by Indian and UK biologists, who attribute the cause to pollution, sand mining and upcoming hydel power projects on the river Cauvery, especially the Mekadatu dam.
First mentioned in HS Thomas’s ‘A Rod in India’ in 1873, the giant fish of the carp family has been known to anglers around the globe as ‘one of the largest and hardest fighting freshwater fish in the world’ and its distribution has been limited to South India’s River Cauvery.
Rajeev Raghavan of the Conservation Research Group of St Albert’s College in Kerala and his British counterparts from the Bournemouth University studied logbooks maintained by 3 angling camps on the Cauvery to come to this conclusion.
These proxy indicators of the eroding population of the orange-finned fish in the Cauvery river show that the fish can survive maximum one more generation and become extinct soon. “This fish is now believed to be so endangered it may be extinct in the wild within a generation,” said Raghavan.
Out of 17 species of Mahseer fish species, 4 are already listed as ‘Endangered’ on the International Union for Conservation of Nature (IUCN) Red List and soon the ‘Humpback Mahseer’ of cauvery basin would join the list, going by these researchers.
Another interesting angle of their research was the introduction of Maharashtra’s blue-finned Mahseer in the Cauvery basin the in the 1980s that made the species survive in abundance but at the cost of native Mahseer, said researchers.
“Without a doubt, their (Maharashtra) success has been at the expense of the humpbacked Mahseer that historically occurred throughout the entire river catchment,” said Adrian Pinder of Bournemouth University in the UK.
Another feature going against humpbacked Mahseer is that it was not named as an entirely different species and hence its extinction will not even make its presence in the records, said Pinder.
“The state of confusion surrounding Mahseer taxonomy means the humpback Mahseer currently lacks a valid scientific name and could potentially go extinct before being named,” he noted and said that it is not too late to obtain DNA from this fish species and name it and include it in ‘critically endangered’ on the IUCN Red List.
Their findings have been published in the journal Endangered Species Research.