Whales are present in Antarctica, with the Southern Ocean serving as a globally recognized marine habitat. This vast, icy region hosts a diverse array of whale species, drawn by its abundant marine life. Antarctica’s ecosystem supports these large marine mammals, providing feeding grounds and, for many, a seasonal home. Its productive waters contribute significantly to global ocean health.
Whale Species of Antarctica
The waters surrounding Antarctica are home to various whale species, broadly categorized into baleen and toothed whales. Baleen whales, known for their filter-feeding plates, include some of the largest animals on Earth.
The Southern Blue Whale, the largest animal to have ever lived, is found here, with a distinct population in the Southern Ocean. Fin Whales, the second-largest whale species, also frequent these cold waters.
Humpback Whales are commonly sighted, recognized for their acrobatic displays and long flippers. These baleen whales can reach over 60 feet and consume thousands of pounds of food daily. Antarctic Minke Whales, while smaller, are abundant and often spotted near the pack ice. Other baleen whales like Sei Whales and Southern Right Whales also visit the region.
Among toothed whales, Orcas (Killer Whales) are prominent and the largest members of the dolphin family. Several ecotypes of Orcas exist in the Southern Ocean, each with varying diets and hunting techniques. Male Sperm Whales, the largest toothed whales, are also found in Antarctic waters, capable of deep dives to hunt prey.
Antarctica’s Rich Feeding Grounds
Whales are attracted to Antarctic waters due to the abundance of food, particularly Antarctic krill. The Southern Ocean is considered the Earth’s largest feeding ground for marine mammals.
This region’s cold, oxygen-rich waters and powerful ocean currents create an environment conducive to life. Microscopic marine plants called phytoplankton bloom under nearly 24 hours of daylight during the austral summer.
These phytoplankton blooms, fueled by nutrients from the deep ocean, form the base of a dense food web. Swarms of tiny marine crustaceans, predominantly Antarctic krill, feed on these phytoplankton.
Antarctic krill are one of the most abundant animal species on the planet, with an estimated 400 million tonnes in the Southern Ocean. This vast concentration of krill provides a feast for baleen whales, which filter these organisms from the seawater.
Seasonal Journeys to Antarctic Waters
Many whale species undertake seasonal migrations to and from Antarctic waters, driven by their life cycle needs, primarily feeding and breeding.
During the austral summer (approximately December to March), whales travel south to the Southern Ocean to take advantage of rich feeding grounds. They spend these months consuming large quantities of krill and other prey to build blubber reserves, which sustain them for the rest of the year.
As winter approaches in the Southern Hemisphere, and food availability diminishes due to reduced sunlight and increased sea ice, many whale species migrate thousands of miles north. They travel to warmer, temperate or tropical waters for breeding and calving.
For instance, humpback whales migrate from Antarctica to breeding grounds off the coasts of Australia and South America. While birthing in warmer, safer waters is a key reason, recent research also suggests warmer waters assist in skin molting.
Protecting Antarctic Whales
Conservation efforts safeguard whale populations in the Antarctic region, which faced severe depletion due to historical commercial whaling.
The International Whaling Commission (IWC) implemented a global moratorium on commercial whaling, effective in the 1985-86 Antarctic whaling season. In 1994, the IWC declared the entire Southern Ocean a whale sanctuary. These measures have allowed some whale populations to begin recovering.
Beyond whaling bans, Marine Protected Areas (MPAs) in the Southern Ocean contribute to whale protection. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) established the South Orkney Islands Southern Shelf MPA in 2009 and the Ross Sea Region MPA in 2016.
These MPAs aim to conserve marine biodiversity and provide safe havens for species, including whales. Despite these protections, Antarctic whales still face threats from climate change (impacting krill populations and sea ice), ongoing krill fishing, pollution, and shipping traffic.