When we think of Antarctica, most of us envision colossal icebergs, fleets of penguins, and frisky seals leaping in and out of the water. We imagine pristine white snow, towering mountains, and oceans dotted with hunks of ice, like floats in a parade. But we know precious little about the marine life that lives in these extreme waters. Curious to understand this habitat, wildlife photographer Dhritiman Mukherjee spent two weeks in the Antarctic Peninsula, diving into the waters around its many islands and photographing its lesser known inhabitants.
Diving around icebergs is always a challenge. Divers have to carry heavy gear, combat extreme temperatures, and deal with equipment far more technical than that required by regular dives. Diving in Antarctica is a whole other ball game. “Everything is constantly moving,” explains Dhritiman. “The icebergs move, the sea ice moves, so in a sense the landscape is always changing. It’s confusing because you have no landmarks, but also hazardous because you have to constantly watch out for breakaway chunks of ice large enough to crush you.”
Add to this, the shifting density of the water. Ice in Antarctica is largely of two types: Icebergs formed from fresh water, and sea ice formed when saline ocean water freezes. They both have different densities, which affects the buoyancy of the diver. If you aren’t mindful, you could drop several feet, or whoosh up to the surface when you approach these ice forms.
For all these reasons, polar diving requires plenty of experience. Before breaking the ice in Antarctica, Dhritiman went ice diving in the Arctic Ocean to photograph orcas, and in Baikal Lake in Siberia where he documented the Nerpa seals endemic to the region. Still, he says, diving in the Antarctic Peninsula was his most trying underwater experience.
It was also his most surprising. “There is a very unique diversity of fauna here,” he says. “Each animal has evolved in very special ways, to combat the extreme habitat.” Seals have layers of blubber to protect them from the cold, fish like the Notothenid have specialised proteins that prevent their body tissue from freezing, while anemone like the Edwardsiella andrillae, are able to live attached to ice. As Dhritiman says, “It’s really quite fascinating.”
Sculpted by the wind, the ice takes on exquisite forms, both above and below the surface. The icebergs are titanic in size, often spanning several square kilometres, and dwarfing the ship as seen in this image.
There are over 35 species of starfish in the oceans around Antarctica. The most striking of these, is the Labidiaster annulatus, which spans over two feet. Unlike most other sea stars that have five rays, the sunshine-yellow labidaster has over 50 spindly rays, which it uses to catch and consume small fish.
Matching in elegance is the salp: tubular, gelatinous sea creatures that are somewhat similar to jellyfish in appearance. Salpa move by pumping water through their barrel-shaped bodies. They are constantly straining the ocean water for algae cells, which they consume for energy.
The strongest swimmer in the region is the Weddell seal, which can dive down 600 metres for food. Hunting at this depth gives them access to cod icefish (their favourite seafood) and keeps them clear of predators such as the leopard seal, which are known to hunt other seals.