The giant mahseer of India’s river Cauvery could become extinct within a generation. Pollution, hydropower projects and blue-finned mahseer, which are not native to the river but were introduced to improve fishing, are all factors sending the population of the orange-finned or humpbacked mahseer to dangerously low levels. Introducing non-native mahseer to boost stocks for anglers has acted as a catalyst that has had a catastrophic effect on the numbers of endemic mahseer, warn scientists who have been studying the species. The humpback mahseer, which is only found in the river Cauvery and its tributaries, can grow larger than 120lb. Adrian Pinder of the UK’s Bournemouth University and Rajeev Raghavan of St Albert’s College in Kerala, south-west India, says their priority is to source specimens of the humpbacked mahseer.“If we are not already too late, obtaining DNA will allow us to get it classified as critically endangered on the International Union for Conservation of Nature’s Red List. Their findings are are reported in the international conservation journal Endangered Species Research.