There is very little light. Clouds obscure the weak moon, and except for the slight glow from the foam of the waves, there is darkness all around. The wind whips up the waves and the fine sand particles abrade my face. It is around 1 am and I am standing on the shores of Gahirmatha beach in Orissa’s Gahirmatha marine sanctuary. Watching the waves makes me feel queasy as it reminds me of the boat journey that had brought me there.
I am also surrounded by turtles. Olive Ridley turtles. This beach is amongst a few beaches in Orissa where turtles gather in large numbers every year to mass nest. Called arribada or “the arrival”, it is a dramatic natural phenomenon. In the gusty dark it was hard to see clearly but the general shapes of turtles filled the eyes for a large stretch of the beach. This is not the main nesting season yet and the first few turtles have just started to arrive. There are about 40 adult females laying eggs around me.
Olive Ridley turtles spend most of their lives in the ocean and come ashore only to lay eggs. Photo: Dhritiman Mukherjee Every year, thousands of female olive Ridley turtles turn up on the shores of Gahirmatha to lay eggs. In 2019 alone, this mass nesting phenomenon, called 'arribada' (arrival in Spanish), saw over 2,00,000 turtles. Cover Photo: Kartik Shanker
Turtles are some of the oldest living reptiles on earth. Some fossils have been dated back to over 220 million years. Sea turtles live in the oceans and only come to land to nest. They are hatched from eggs buried in nests dug into the sand by female turtles. Hatchlings dig their way out from their nests and then make their way back to the ocean. The females, when sexually mature, return to the beaches of their birth to lay eggs. How they navigate out of their nests to their ocean homes and how they come back to the beaches where they are born was a mystery for a long time. Many theories abounded but recent science suggests that individual beaches have magnetic fields unique to them. When the turtles hatch, these fields are imprinted into their brains, allowing them to sense it when they need to return. It’s a magnificent internal compass as accurate as the latitudes and longitudes used by humans.
As the horizon turns a little and I can see better, I follow one turtle up from the ocean. This female could have been anywhere from fifteen years or older. Fifteen is the earliest age at which they reach sexual maturity. They live for 60-80 years. They mate with males in the ocean and then use wind and tides to reach the beaches. Usually solitary by nature, the mass nesting where they can gather in numbers of over 50,000 at a time is unique to the olive Ridley and Kemp’s Ridley.
The olive Ridley is the second smallest of the sea turtles. They weigh up to a 45 kilograms and are about 1m to 1.2 m long. There are eight separate species of sea turtles, with the olive Ridley being the most prolific with an estimated population of 8,00,000 females. They are a schedule 1 species in the Wildlife (Protection) Act while listed as vulnerable by the IUCN Red list of species. They are found in the Pacific and Indian oceans and in the warmer parts of the Atlantic Ocean.
Growing up to 60 cm and weighing up to 50 kg, the turtle has greenish skin and an olive shell. Photo: Dhritiman Mukherjee
She looks awkward and clumsy as she makes her way up the beach. She is also entirely unconcerned by my presence. She stops, rests a little in contemplative silence. She then starts to move in a peculiar twisty way and then uses her flippers to start digging. All I can see is sand flying at a furious rate everywhere. I stand at a distance watching the oval lumbering being, wondering how she manages to dig her nest. Having been on turtle walks to not only protect nests but then to also remove eggs from vulnerable nests in order to give them a better chance to survive in Chennai, I know that she will create a space in the sand that is shaped like an earthen pot. The nest is deep and round with packed mud which will not collapse unless disturbed. My arm on the day I helped collect eggs disappeared into the nest almost armpit deep and I could feel how round and perfect it was. It still mystifies me that she can do that with just her flippers when I cannot do it with my supposedly dexterous hands!
She holds still as soon as she stops digging and I can see her strain. I know she was laying her eggs then. The eggs have to drop into the nest and often land on top of each other. In order to prevent them from cracking, the eggs are almost leathery in texture and dent in places where pressure is applied. This gives them a certain flexibility and toughness. She can lay up to 100 eggs at a time and in one season she will come up at least twice if not more to lay. Usually the first wave of turtle nesting is a bit of a disaster. This is because often the second wave of turtles can come up and dig over existing nests. It gets more problematic when nesting beaches shrink reducing nesting spaces. The eggs that don’t hatch and rot feed the sand with nutrients allowing coastal vegetation to thrive.
Sea turtles are threatened by the unchecked development of coasts, the proliferation of ports, shipping lines and trawling by fisheries. Bottom trawling for shrimps and prawns kills tens of thousands of olive Ridleys every season and I have seen dozens of turtles trapped in nets dead with their eggs spilling out of them. Turtles are also killed for their magnificent shells, their meat for turtle soup and their eggs too are consumed.
These solitary reptiles come together once a year for the arribada, when females, sometimes in thousands, return to nest on the beaches where they were born. Photo: Dhritiman Mukherjee
Life is hard for olive Ridleys. Perhaps one in a thousand babies make it to adulthood, and killing of sexually mature females is a critical issue. Climate change is also causing problems with rising sea levels changing coastlines, shifting the contours of beaches and also affecting the sex ratio of the turtles. As with all reptiles, it is the temperature of the sand around the eggs that decides whether a hatchling will be a male or female. A shift to higher temperatures can affect that fragile balance.
Sea turtles eat algae, seaweed, sea grass, lobsters, crabs and tunicates. Their grazing allows the sea grass and seaweed to grow better. Richer the growth of sea grass and seaweed, the more carbon the ocean can sequester, making the sea turtle a keystone species, essential to the health of the oceans.
The turtle's eggs are shaped like golf balls and have a leathery texture that allows them to dent without breaking when they drop. Photo: Dhritiman Mukherjee
I am now sitting near the nesting female, watching her intently, as tears roll down from her eyes. It’s always disconcerting to see this. Intellectually, I know that her body is just shedding excess salt and protecting her eyes from the sand, but emotionally, it’s still something that touches my heart. I reach out to touch her carapace and immediately the area where I rest my hand is lit up in a ghostly glow. Phosphorescence or bioluminescence caused by some of the algae on her shell. Again, science has an explanation, but to my palm it was like touching something magical.
I think of the hatchlings that will struggle out after two months. I think of how they will push their vulnerable little bodies out of the sand onto the beach and then make their trek to the water. I think of the hundreds of sea gulls, crows, Brahminy kites and dogs that will kill them. I think of the tiny fragile baby making its way to the water and then being overwhelmed by waves. I think of the ones who won’t make it out of the sand. And then I think of the one who would, swim into that vast ocean, so small in a such a big world filled with hungry mouths. Then finally I think about how one female will against overwhelming odds survive and come back to this very beach like her mother. My respect is huge and my heart heavy with apology for adding the greatest threat they face — human activity and human exploitation. Maybe that’s why I reached out and laid my hand softly on her shell.
Olive Ridley turtle hatchlings making their way to the ocean have to overcome a multitude of threats, which include predation by crows, crabs and dogs. Photo: Dhritiman Mukherjee
We still don’t know exactly where baby turtles go and how they live to survive to adulthood and what their migratory distances and passages are like. We are still finding out through radio telemetry from turtles with attached satellites. Her job done she goes back to the water while others lumber out from the ocean.
We must be aware of the fact that any prawns and shrimps we eat that are brought in by trawlers kill these magnificent animals. There is a device called the turtle excluder device or the TED, a gate-like device on trawl nets that allows bigger animals to push their way out, that can be fitted to reduce the killing. India has a terrible track record of enforcing this as evidenced by the numbers of dead turtles that wash up every season. We must pressurise the authorities to ensure that better practices are followed.
These beautiful creatures survived catastrophic events that wiped out the dinosaurs, including a meteorite, on their own. They could now do with a little help from humans to secure their future.
