“Antarctic krill, such endearing little critters. No wonder they’ve entertained scientists for generations,” marine biologist Angus Henderson says. Despite their diminutive size, these creatures, shown here in a shipboard lab, “support the entire ecosystem of the Southern Ocean,” the waters encircling Antarctica.
Henderson, a doctoral student at Australia’s University of Tasmania, captured these photos in January as one of 20 Australian Antarctic Program scientists who spent two months aboard Investigator, a Commonwealth Scientific and Industrial Research Organisation research vessel. Henderson worked as a predator observer on the expedition, keeping an eye on the whales and snapping photos whenever he had a free moment.
The purpose of the mission: To collect data off East Antarctica to determine how many krill live there and how they interact with the penguins, whales and other predators that depend on them.
The data will inform efforts by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) to update its krill fishery management measures, including protective catch limits.
Protections like these aren’t just for the sake of krill: Not only do these shrimp-sized crustaceans serve as the base of the entire Southern Ocean food web, they also store carbon equivalent to the yearly emissions of 35 million cars.
Plus, according to Henderson, they’re just plain pretty: “I was inspired by how beautiful these little guys are when they’re swimming around.”
Surrounded by massive icebergs, wild ocean waves, and even the great Southern lights, Henderson found his first trip to Antarctica—featured in a recent “takeover” on the @PewEnvironment Instagram feed—to be an amateur photographer’s dream.
Listening for whales
Researchers deployed sonobuoys during the voyage to acoustically detect whale communication from up to hundreds of kilometers away.
“This piece of tech—called a sonobuoy—records sound while we’re underway,” explains Henderson. “They’re thrown overboard and stay at about 300 meters below the surface.”
“We put hundreds of individual krill in jars—which I termed krill high-rise, or apartment, living—hoping that a portion of them would molt,” says Henderson, remarking on this photo of Abbie Smith, a trace-metal chemist.
Smith wears gloves to handle the frigid containers and a headlamp to examine the precious cargo.
“We then measured the molt length and the krill length,” Henderson adds, “which gives us some idea of how much the krill are growing.” This is important information for determining management strategies in the Southern Ocean.
“We came across a huge super-swarm of krill around 100 meters thick and more than 2 kilometers long. And, as you would expect, if we found them, so did the whales,” recalls Henderson. At one point, “we had around 80 whales within 2 kilometers of the vessel, feeding continuously.”
Rough days at sea
The parameters of the research survey required the team to reel in the krill net even in heavy snow and stormy seas.
“I thought the deck crew would like this photo,” Henderson says. “They often work in temperate and tropical regions, and not often in snow.”
Southern lights surprise
“We’d been waiting to see an aurora australis all trip,” Henderson remembers. “On this night, the third mate woke us up to let us know there was an aurora visible.
“My cabin mate and I charged up seven flights of stairs to the bridge, which was filled with excited scientists like myself in complete darkness.”
“It's rare to have the spray, light, and such a beautifully shaped berg at the same moment,” Henderson says of this image of one of the expedition’s final iceberg sightings. “She was far away, but we passed close enough to capture it with a 400 mm lens.”
Like this scene, lasting protections for Antarctic seas are tantalizingly close—yet elusive.
When it meets in October, CCAMLR will have an opportunity to live up to its mandate to protect the Southern Ocean and its marine life.
The Pew Charitable Trusts and its partners call on CCAMLR to adopt ecosystem-based fisheries management practices and establish a network of large-scale marine protected areas around Antarctica to protect this spectacular region.
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Nicole Bransome works on The Pew Charitable Trusts’ protecting Antarctica’s Southern Ocean project.