On a bright May morning, a helicopter lifts off the Esperanza, a Greenpeace ship, and heads north, tracking the edge of the sea ice east of Greenland. Below us is Fram Strait, a deep ocean channel and one of the Arctic’s richest feeding grounds, where narwhals, bowhead whales, and beluga whales gather each spring to feast at the ice edge.

We’re on the lookout for these ocean giants. It’s day three of a two-week expedition, and so far, there’s no sign of any whales. Already, the sea ice is melting, releasing some of the richest fare on offer in the frozen Arctic: ice algae, specialist life forms that live in water pockets at the bottom of the