Survey of odonates reveals alarming pollution in Meenachil

A latest survey of odonate habitats along the Meenachil river has revealed alarming levels of pollution, with the exception of the river’s source at Meladukkam.

Conducted on Sunday by the Social Forestry Division of the Kerala Forest department in collaboration with the Tropical Institute of Ecological Sciences, the survey found that the population and diversity of odonates in the region have remained largely unchanged. This year, researchers identified 44 odonate species, including 24 dragonflies and 20 damselflies. The findings highlight climate change and pollution as major factors contributing to the decline in odonate diversity.

Over the past ten years, survey results have shown that the diversity of commonly observed dragonflies is significantly lower compared to damselflies. While dragonflies were abundant at most locations along the river, they were less common near Meladukkam, the river’s origin point.

Species such as the Pied Paddy Skimmer, Blue Grass Dart, and Trumpet-tail were observed along the entire stretch of the Meenachil riverbanks. Relatively rare species, including the Black and Yellow Bambootail and Little Blue Marsh Hawk, were recorded at sites such as Kidangoor and Illickal. At the upper reaches of the river, freshwater indicator species like the Black Torrent Dart and Stream Ruby were also found.

“The increasing degradation of aquatic ecosystems poses a serious threat not only to odonates but also to human health and the well-being of other animal populations,” said Assistant Conservator K.B. Subash of the Social Forestry department, who led the survey.