While the vegetation cover around the Meenachil appears to be on a decline over the years, the growing habitats of odonates that thrive along the river banks here has brought a glimmer of hope to the conservationists.
A day-long survey conducted by the Tropical Institute of Ecological Sciences (TIES) in association with the Social Forestry wing of the Kerala Forest Department to assess these myriad little beasts on the Meenachil's banks, has recorded a remarkable rise in its population. The field exercise, carried out along 11 locations from the river's origin in Marmala-Meladukkam stretch to its ending at Pazhukkanila lake, identified 54 types of odonates including 32 varieties of dragon flies and 22 types of damsel flies.
Commenting on the survey, Punnen Kurian, Secretary, TIES, said the survey recorded large-scale sightings of the species such as Common Picture Wing, Rudy Marsh Skimmer, Pied Paddy skimmer, and Trumpet Trail etc. At the same time, the study also confirmed a sharp decline in the presence of Ditch Jewels, which breed in contaminated water.
“The decline in population of Ditch Jewels points to improvement in water quality. This makes us hopeful but what we are trying to convey is cautious optimism,” he said.
Adding to their delight, the survey also noticed the wide-spread presence of fresh water species such as Malabar Torrent Dart and Stream Ruby along the upstream locations of Adukkam and Marmala. The population of Black and Yello Bamboo Tailed flies, which are mostly spotted in north Kerala, too reported a rise.
Mr. Kurien attributed the decline in Ditch Jewel population to the extension of northeast monsoon till December last year and decline in sewage discharge though there could still be some unknown factors at play. “The surveys held in previous years suggested a steady growth in the population of this species, especially around the Kottayam Town. The COVID-19-induced lockdown and the consequent improvement in local environment, however, brought about a turnaround,” he added.
Among the locations, Kidangur-Punnathara region reported the highest variety of odonates while Thazhathangadi-Illikkal region in Kottayam reported the lowest numbers.
As many as 87 students and led by one expert each locations took part in the survey, which was held on Sunday.
