Antarctic krill, a shrimp-like crustacean that supports the food web at the South Pole, were discovered at a hydrothermal vent off the Antarctic Peninsula during the National Geographic and Rolex Perpetual Planet Southern Ocean Expedition in collaboration with the Schmidt Ocean Institute.

Importance of Antarctic Krill

These shrimp-like crustaceans are a crucial food source for penguins, seals, and whales. Kim Bernard, a biological oceanographer at Oregon State University and a National Geographic explorer, stated, "Most of them feed on Antarctic krill. And if they don't, they feed on something else that feeds directly on Antarctic krill. So they are absolutely fundamental to the functioning and health of that ecosystem."

Krill also play a vital role in recycling nutrients that allow tiny algae called phytoplankton to grow. Additionally, they are fished in large numbers to produce aquaculture feed and omega-3 fatty acids as dietary supplements. However, experts warn that this rich habitat in the Southern Ocean is rapidly changing due to climate change. Bernard noted, "It's one of the most rapidly warming areas on the planet, and that's cascading through the food web and affecting the Antarctic krill population."

Discovery at Hydrothermal Vents

In a recent study published in the journal Communications Biology, Bernard and her colleagues reported the surprising discovery of krill at hydrothermal vents, which are essentially hot springs on the ocean floor. Characterizing the importance of this habitat, especially for reproductive females, may help inform conservation efforts for these crucial crustaceans.

Antarctic krill typically inhabit the upper layers of the ocean. Bernard explained, "They can be found forming swarms and layers at the surface. You can photograph them from airplanes." However, deeper observations have been sparse and anecdotal.

In late 2024, while aboard the National Geographic and Rolex Perpetual Planet Southern Ocean Expedition, Bernard was in the Bransfield Strait off the Antarctic Peninsula. Her colleague, Andrew Thurber, a benthic ecologist from UC Santa Barbara, was using a remotely operated vehicle called SuBastian to study a hydrothermal vent approximately 3,600 feet below the surface.