Wild Sounds: Voice of the Sea Ice

Welcome to Antarctica - a land of ice, extremes, and ambition. From historic expeditions to modern day science projects, Antarctic exploration is a unique, and dangerous, experience. We meet one researcher involved in an epic journey across the largest ice shelf in Antarctica, mapping a safe route through a crevassed landscape for others to follow. Plus, we learn about the different types of ice found in this vast, frozen landscape.

Step out on the sea ice just outside New Zealand’s Scott Base with researchers studying the physics of its annual cycle. Each year a massive patch of ocean around Antarctica freezes and then melts again come summer – Antarctica’s heartbeat. In winter, the ice effectively more than doubles the size of this already massive continent, and it plays a huge role in controlling our planet’s climate.

What’s it like to live and work on the frozen ocean? A team of researchers are camping out on the sea ice to investigate the small critters that live on the bottom of the ice, and among the sloshy platelet ice layer just below it. From microalgae to krill, these tiny organisms hold up the big complex food web of Antarctica. Scientists are keen to understand these communities, and how they might shift as the sea ice cycle changes.

Penguins that return to the ice in the middle of winter to lay their eggs. Seals that use cracks in the ice to keep their pups safe. And fish that have antifreeze proteins to survive in the icy cold waters... Antarctic life is tough, and full of surprises. Scientists are keen to piece together the Antarctic food web puzzle to better understand the interconnections, and to enable smart conservation decisions.

In February 2025, the world hit a new low for global sea ice extent. Arctic sea ice has been declining for several decades now, but Antarctic sea ice had been holding steady, until recently. With low summer sea ice extents for four years in a row, it appears that Earth’s warming has kicked Antarctic sea ice into a new regime. Claire Concannon speaks to scientists to understand what this means for Antarctica, what this means for us, and how they feel about it.