Oussudu lake | Photo Credit: Mohan Ganesan
A raft of Garganey ducks blithely paddle past. On the banks of Oussudu lake, Raphaël Mathevet watches them thoughtfully through a powerful pair of binoculars. “There has been a decrease in the wintering duck population here,” he says, pointing out that the man-made lake — declared a bird sanctuary by the Puducherry and Tamil Nadu governments in 2008 and 2014 respectively — has hosted ducks from Central Asia, Siberia and northern India for decades. “Flocks now are smaller than they were in the 80s and 90s, and we are not able to understand why,” he adds, discussing why it is important for research institutions to network and decode patterns of migration.
Mathevet is a senior scientist at CNRS, which is the French National Centre for Scientific Research. He works with CEFE, in Montpellier, France, currently the largest French research centre in Ecology and Evolutionary Ecology, and is on deputation as the Head of the Department of Ecology at the French Institute of Pondicherry.
With an interest in the political geography of conservation and integrated management of ecosystems, Mathevet is now working on a project that studies and compares two kinds of wetlands: “The man-made ones, like Oussudu and the natural ones, like Kaliveli lake.” Which is why he’s standing on the shores of the lake at 8 am, with a group of interested birders, leading a ‘Wetlands tour: Oussudu Lake Adventure’ as part of the ongoing Pondicherry Heritage Festival.
The century-old lake, which attracts about 20,000 migratory birds every year, is around 12 kilometres from Puducherry and has been designated one of the most important wetlands in Asia by the International Union for Conservation of Nature.
Pointing out a cotton pygmy goose meandering past, and a gang of self-important egrets, Mathevet says the lake is interesting because of the rich biodiversity it supports. “Originally made for irrigation, the water comes from the Gingee river and when it rains, it fills in one or two days. It is very fast,” he says, adding, “Now it is a bird sanctuary, but it is also being seen as a water source as the population around it is rising every year. There is a high tourism demand as well.”
The challenge, he says, is how best to manage it all, without threatening the wetlands. “We have about 75 to 100 species of birds here through the year,” he says. Though these are mostly herons, pelicans and storks, in a couple of hours, Mathevet manages to show his group of birders darters, cormorants, Indian spot billed ducks, bee-eaters, terns, drongos, herons and the glossy ibis.
“I would say the species that is the most threatened is cotton teal. The spotted-billed pelican as well, though it is common locally, it’s rarer to find globally,” says Mathevet. “Though due to climate change, resulting in a reduction of fresh water in wetlands, it is important to protect all of them.”
A World Wetlands and Climate Change photo competition was conducted as part of the Pondicherry Heritage Festival. Entries are on public display at the Institut Français de Pondichéry, 11, Rue Saint Louis Street till February 28, 2019.