Photojournalist Alexandre Meneghini knew the voyage to Antarctica might be a bumpy ride. But he refused to take motion sickness pills. "That was a mistake," he later admitted. At times, he felt like he was inside a centrifuge. Especially here, in the infamous Drake Passage — a body of water near Cape Horn where the Pacific and Atlantic oceans converge.

But Antarctica's stunning natural beauty makes the rough seas worth enduring. On this voyage organized by Greenpeace, whales surfaced near the research ship multiple times. More than a dozen species of whale spend at least part of the year in Antarctic waters, including the blue, Minke, humpback and sperm whale.

But Meneghini also saw more worrying activity on the horizon. This krill-fishing vessel was spotted in Crescent Bay. For a long time, krill was of little interest to humans. Now, they are being targeted by the fishing industry, which markets krill oil as a source of omega-3. That's a problem, according to Greenpeace, as almost all Antarctic animals in rely on krill as a staple food.

Meneghini's journey though the Antarctic featured some unforgettable moments, and encounters with penguins certainly ranked among them. Here, he came face-to-face with a colony of Gentoo penguins on Cuverville Island. Krill makes up the bulk of these birds' diet.

Gentoo penguins waddle across an ice-free spot in Neko Harbor. Meneghini said getting so close to penguins on shore made him feel like a kid in a sweet shop. "If you don't move, the penguins will stay close by for hours," the photographer said.

A fur seal takes a break from the water in Maxwell Bay. Fur seals were hunted to close to extinction by the early 20th century. Since then, their numbers have recovered. Still, individual animals are at risk of getting entangled in shipping debris. And although they also feed on fish and even penguins, fur seals could come under pressure from krill fishing, conservationists warn.

Of course, Antractica wildlife isn't only threatened by fishing. Climate change is eroding the continent's glaciers faster than expected. That's disrupting local species' habitat — and threatens to force global sea levels up to the point where some worst-case scenarios see all the world's coastal cities wiped out before the end of this century.