The International Union for Conservation of Nature (IUCN) has classified this species as 'vulnerable'. In addition to the otters, researchers recorded 35 mammal species, including deer and mongoose, as well as 67 types of plant species.
The study also documented 175 bird species in the area, with 12 of them classified as vulnerable. Conducted by the Madurai Nature Cultural Foundation from August 28 to September 6, the research aimed to assess pollution levels in the Vaigai River.
Results indicated that the river is heavily polluted and unsuitable for consumption. Water samples collected from 28 points along the river were found to be highly contaminated and classified under category ‘E,’ the lowest in water quality grading.
Additional samples from 36 points showed alarming levels of contamination, largely due to pesticide pollution. Sources from the Water Resources Department (WRD) stated that while water quality is better at the river’s origin, it deteriorates downstream due to human activity.
The study noted the presence of birds like coots and the glossy ibis, which are typically found in waters with high sewage contamination. Alarmingly, there has been a decline in the number of storks, a species sensitive to water quality.
The drop in stork populations serves as an indicator of severe water pollution. Researchers also highlighted the proliferation of invasive plant species, such as water hyacinth and various types of grasses, which obstruct the waterway and further degrade water quality.
The research team included botanists N. Raveendran and N. Karthikeyan, along with a group of dedicated volunteers. R. Palaniswami, a Professor of Environmental Studies based in Tamil Nadu, urged the government to take immediate action to restore Vaigai River.
“The Vaigai is the lifeline of several southern districts in Tamil Nadu and holds cultural significance. Strong intervention at the level of the Chief Minister is essential to restore the river to its former state,” he said.