Pollution Endangers Rare Fish in Tamil Nadu River

The Tamirabharani River, unique for originating and flowing entirely within Tamil Nadu, harbors a rich fish diversity including seven endemic species. A recent survey identified 125 fish species in its various stretches. However, pollution, habitat loss, invasive species, and human activities are severely impacting these native populations.

Endemic species are vital indicators of a river's ecological health. Scientists have noted that five endemic species are still surviving, but two found outside forest areas are under significant threat. The potential extinction of these species raises alarms about the river's overall condition.

Several endemic species are particularly vulnerable. Dawkinsia tambraparniei, known locally as Tamirabharani Seval Kendai, is listed as endangered by the IUCN due to declining numbers. Haludaria kannikattiensis, found only in a small area within the Kalakkad-Mundanthurai Tiger Reserve, is a steno-endemic species. Other unique species include Neolissochilus tamiraparaniensis, Mesonoemacheilus tambaraparniensis, Garra kalakadensis, and Hypselobarbus tamiraparaniei.

Adding to the challenges, invasive fish like tilapia and African catfish compete with native species for resources and prey on their eggs. The destruction of riverine vegetation further exacerbates the survival and breeding issues for the local fish fauna, signaling a critical environmental crisis.