Warming waters, a world under threat

Dhritiman Mukherjee has photographed snow leopards in Leh and swum with crocodiles in the lagoons of Mexico. But the locations that draw him back more than any other are frozen-over lakes and seawaters.

Mukherjee, 46, who works as a Sony Explorer and has had work published in Sanctuary Asia, has dived into Lake Baikal in the Siberian winter, and conducted shoots between and beneath icebergs in the seas around the Arctic and Antarctic.

Temperatures in these waters are typically between 1 and 3 degrees C. “You need to be in an airtight thermal suit, with a special regulator for the oxygen cylinder that won’t seize in the cold, and with enough light to see what’s down there,” says Mukherjee, who lives in Kolkata. “Freshwater ice is translucent, so there’s a bit of light coming through. But when you duck under sea ice, which is opaque, it’s completely dark.”

Once all the gear is in place, divers descend through a hole in the ice, with a tether around the waist. The tether is their only link to the surface. “If I lose the rope, there would be really very little chance of me finding my way back to the hole, under that vast expanse of ice,” Mukherjee says.

At the poles the challenges get more intense. “Summer dives at the poles mean navigating between icebergs that are constantly moving.” One has to always look out for breakaway chunks that could crush you.

Divers don’t tend to stay for more than 30 to 40 minutes at a stretch. But in that time, one enters a different world. Under a metrethick sheet of ice or between moving icebergs, alien-looking creatures reveal themselves: giant jellyfish, star fish in all sizes, translucent ghost shrimp, amoebic sea snails, vibrantly coloured molluscs called nudibranchs that look a bit like large caterpillars from a child’s drawing book.

Mukherjee has been cold-water diving for five years and one of his main concerns returning to a place like Antarctica, where permanent ice structures dominate the landscape, is witnessing their depletion. “The sea ice is breaking off earlier than usual,” says Mukherjee. “And because the ice is melting, you can now go to some places which were inaccessible before, and you can’t access some places now because there are more icebergs in the water.”

From aiming to discover what kinds of creatures chose to live in such waters and how they did it, his photographs are now a form of climate-crisis activism. His job as he sees it, he says, is to document how life is adapting to the changing climate.

“Most people are not connected with these kinds of extreme environments, don’t know what they look like or what creatures live there,” Mukherjee says. “It’s my quest to show how beautiful the world can be, how diverse, and what kind of effects people can have on it.”