PALMER ARCHIPELAGO, ANTARCTICA – A few years ago, an icebreaker dragged research nets around the Palmer Archipelago, looking for Antarctic silverfish—oily, sardinelike creatures that spawn beneath sea ice. They used to be the dominant fish off the western peninsula, composing half of what some Adélie penguins ate. But the team, led by Joseph Torres of the University of South Florida, towed day and night around Anvers and Renaud Islands and never caught a single silverfish. In waters that have experienced some of the greatest sea-ice declines, the fish had all but disappeared. Meanwhile scientists noticed penguins gulping more krill—even though it can take 20 krill to match the caloric value of one silverfish.
Will there be enough krill to go around? It’s not an easy question. Penguins and humpbacks eat krill, but so do skuas, squid, fur seals, and crabeater seals. Leopard seals sometimes eat krill. A blue whale eats millions a day. Animals that don’t eat krill often feed on prey that does. Antarctica loves fatty krill. So do we.
In the 1960s, seeing a potential new seafood source, Soviet fleets began circling the continent. Today about 10 ships a year catch krill, led by Norway, South Korea, China, Chile, and Ukraine. The catch turns up in omega-3 pills and chewable krill-oil gummies and farmed salmon. In Ukraine peeled krill is sold in tins, like sardines. Sometimes krill gets processed at sea, boiled and dried into powder on huge trawlers.