There are three ways to watch the dense green mangrove forests that distinguish Adyar creek and estuary: up, close, and personal.
From up, on Adyar bridge, I see bush-like trees all along the water — “from Pattinapakkam to Thiru.vi.ka bridge,” says an official from Chennai Rivers Restoration Trust (CRRT), the organisation behind the development of Adyar eco-park. I walk through a red picket gate on the bridge and descend the slope to a walkway made with stones.
A 500-metre gingerly-executed trek takes me to an Amman temple that fishermen from Foreshore Estate visit on Fridays, where they clean the space and offer puja. The path to the small temple is lined with mangrove so thick, that you have to look closely to glimpse the river through them. From the bridge to the river bed, you can see mangroves growing on the seven islands inside Adyar river.
Planting native mangrove trees was part of the eco-restoration of Adyar creek and estuary. The Theosophical Society and northern bank of Adyar river have two islands where trees, which are over 40 years old, stand proudly. CRRT slashed out prosopis juliflora (karuvelam) on the seven islands and planted mangroves — spawning breeding grounds for fish.
Inside 58-acre Adyar Poonga, you can observe mangroves closely, to soak in all their scientific glory. Walking along the trail near the creek, I stop to observe the gravity-defying, breathing roots of the trees. They stick out from the ground, forming a mini-forest of their own.
I climb the fenced highground to feast on a remarkable sight — salty backwaters on one side of the trail and a man-made sweet rainwater lake on the other. While mangroves line the backwaters, a tropical evergreen forest — native vegetation of the east coast — surrounds the rainwater.
A group of students from Nadukuppam Government School hiking the trail enthusiastically explain the bio-diversity bucked-up by this arrangement. “The fish and other creatures are different on the two sides,” says one of the students, “On the mangrove side there is more density and diversity since the roots provide shelter to the fish.”
In Phase II (2015 to the end of 2016) CRRT planted 55,000 saplings of six mangrove varieties. Some were lost in the December 2015 floods, but the Trust took up the challenge of replanting.
“It was both a biological and engineering intervention,” said the officials. “We consulted a wildlife biologist, zoologist, hydrologist and a botanist — and plugged saplings every three to four metres. What you see now are second and third generation bushes — a success story, thanks to tidal water interaction.” When sea water level increases, tidal water enters the mangrove forests, maintaining the level of salt it needs to thrive.
The forest is alive
The impact of mangroves on the estuarine ecology has been dramatic.
Mangroves act as flood-barriers, curtail wave activity, and in Pichavaram and Muthupettai, arrest currents. They trap the silt thereby enriching the soil around their base. Their aerial roots offer a safe haven to fishes, birds, turtles, snakes and insects, allowing them to breed in peace. It is a secure place for young and sub-adult creatures. The fish feed on the high-protein mangrove leaves. Fishing activity, affected by the tsunami in 2004, has also been revived.
Mangrove forests act as a buffer zone, offering a breeding ground for migratory birds.
The third trail winds through Foreshore estate. The students and I pass a composting yard, walk outside a big gate, and onto a track on the edge of the backwaters.
From this side, where the Central Institute of Brackishwater Aquaculture has a lab enclosure, we spot mangrove thickets on the opposite side of water. The track takes us behind Chettinad Palace, Jain Housing and the Leela Palace hotel.
The lovely 500-metre walk ends with a view of the mudflats, where the river surrenders to the sea.
Visit www.chennairivers.gov.in for Adyar eco-park timings
In this column, we document the city’s lesser-known oases for you to explore