SEPTEMBER 2009 Climate Change Threatens Penguins By: Shaye Wolf Penguins are not just found in •11 of 18 penguin species are Antarctica declining and considered an Penguins—waddling wonders of extinction risk the Southern Hemisphere Although penguins are commonly associated with Antarctica, penguins •Two species are considered Penguins (order Sphenisciformes, are found in a variety of habitats stable. family Spheniscidae) are flightless in the Southern Hemisphere. seabirds found almost entirely in Eighteen different penguin species •The population status of the the Southern Hemisphere. Although inhabit areas from Antarctica to the remaining five is unknown. their wings have become useless for Equator. They can be divided into Studies have linked climate change flight, they have become superbly three groups: to past, ongoing, and projected adapted to swimming and diving. population declines of many For example, Gentoo penguins •Four penguin species breed in Antarctica and/or the Antarctic penguin species. Because penguins can swim up to 35 km per hour— live in different ocean habitats of compared with 9 km per hour for islands: the Emperor, Adélie, Chinstrap, and Gentoo penguin. the Southern Hemisphere, climate the fastest Olympic swimmer. change affects penguins in these Emperor penguins can dive to •Most penguin species breed on regions in different ways. depths of more than 520 m to find islands in the sub-Antarctic waters food—deeper than any other bird. of the Southern Ocean (a.k.a. How is climate change affecting Penguins must return to land or sea Antarctic Ocean), the South Atlantic Antarctic penguins? ice to rear their young, however, Ocean, the South Pacific Ocean, and they are renowned for their The Antarctic continent is warming and the Southern Indian Ocean: as a whole,1 but the Antarctic feats of endurance as parents. The the King, Southern Rockhopper, Emperor penguin raises its chick on Peninsula—the northernmost Northern Rockhopper, Macaroni, region that juts out towards South top of the frozen Antarctic Ocean and Royal penguin. Several penguin amid winter temperatures as low America—is warming faster than species are found only on the any other place in the Southern as -60°C and winds of 195 km per coastlines and islands of Australia hour. For two months, the male fasts Hemisphere.2 Because of this rapid and/or New Zealand: the Little warming, sea ice along the western while taking on the sole duty of Blue, Snares Crested, Erect Crested, incubating the egg, which he must Antarctic Peninsula is shrinking Fiordland Crested, and Yellow-eyed in size, and the sea-ice season is balance on top of his feet to protect penguin. it from the ice below. shorter.2 The loss of sea ice is •The most northerly penguins breed harming Emperor penguin chicks along the more temperate coasts and adults. Emperor penguins rear of South America and Africa: the their chicks on land-locked sea ice. Humboldt, Magellanic, Galápagos, When sea ice breaks up before their and African penguin. chicks have matured and grown their waterproof feathers, chicks Penguins are a highly threatened that are swept into the ocean are group. According to the International likely to die. For adults, the loss Union for Conservation of Nature, of sea ice can lead to lower food Macaroni Penguin (Eudyptes chrysolo- the world authority on the status of availability, which can result in phus) on Hannah Point, Livingston Is- threatened species: increased mortality. land, Antarctic Peninsula, sports colorful crests. Photo: Jerzy Strzeleck exceed 1.3°C of warming before mid-century.11) Penguin scientists also predict that sea-ice loss due to global climate change will push the Emperor population chronicled in March of the Penguins to the brink of extinction within this century.12 How is climate change affecting sub-Antarctic penguins? For the penguin species that live in the Southern Ocean, which encircles Antarctica, global climate change is also having significant impacts. In the Atlantic sector of the Southern Ocean, ocean warming and the melting of sea-ice are linked to the decline of the penguins’ major food supply—Antarctic krill. Krill in this region have declined by as much as 80% since the 1970s.13 The loss of sea ice is linked to of pebbles on the sparse areas of Since krill graze on algae that grow Emperor penguin population the Antarctic shoreline that are free on the bottom of the sea ice, the declines at the warmer northern of ice and snow.6 On the western loss of ice leads to the loss of krill. regions of Antarctica: Antarctic Peninsula, warmer Researchers project that a 1°C rise temperatures allow the air to hold in sea surface temperature in this •The Emperor colony at Terre more moisture, and this leads to region could result in a further 95% Adélie in East Antarctica—featured more snowfall in the region.7 reduction of krill.14 This collapse in in the Academy Award-winning Adélie penguin populations are the food supply would be disastrous French documentary, March of the disappearing rapidly because they for the penguins like the Macaroni, Penguins3—plummeted by more cannot find snow-free ground for which has already suffered a 50% than 50% in the late 1970s during nesting.8 The loss of winter sea ice population decline at its main a warm period with little sea ice in this region is also impacting the breeding site in this region—the cover, when adults died en masse.4 Adélie’s food supply negatively.9 South Georgia Island—between the Because the sea ice continues to As sea ice declines, the more ice- mid-1970s and mid-1990s.15 disintegrate, and the prolonged intolerant Chinstrap and Gentoo There is also evidence that ocean blizzards cause ongoing chick penguins are expanding southward warming has led to penguin mortality,4 the colony has yet to into Adélie breeding areas in the population declines in other regions recover. Antarctic Peninsula, replacing of the sub-Antarctic by reducing Adélie penguins.10 •On the fast-warming Antarctic their food supply. Peninsula, another Emperor colony Both Emperor and Adélie penguins •On Marion Island in the southern has declined from 250 pairs to 10 face a bleak future from global Indian Ocean, a 60% decline in pairs since 1960, due to the rapid climate change. According to a Southern Rockhopper population,16 loss of the sea ice.5 study by Antarctic researchers, and a 50% decline in the Macaroni a temperature increase of 1.3°C Another Antarctic penguin that is population have been attributed to will jeopardize 40% of the world’s being affected by global climate ocean warming17. change is the Adélie penguin. Emperor penguins and 70% of the Unlike the Emperor penguin, the world’s Adélie penguins—largely •On the sub-Antarctic islands of Adélie does not raise its chicks on because of diminishing sea ice.5 New Zealand, Southern Rockhopper sea ice. Instead, it builds a nest out (At present rates, the world will For example, the Galápagos Our greenhouse gas emissions are penguin has proven to be extremely also causing the oceans to become vulnerable to starvation during acidic, which threatens the entire El Niño events. Adults are forced ocean food web from plankton to abandon their eggs and chicks to penguins. The oceans absorb a to search for food, leaving their large portion of the carbon dioxide chicks to starve.20 Following produced by our industrial society. the powerful El Niño events of As ocean waters have absorbed this 1982–1983 and 1997–1998, the excess carbon dioxide, the acidity Galápagos penguin population of the ocean has increased by 30% Adélie Penguin (Pygoscelis adeliae) feeding plummeted by 77% and 65%, and carbonate ions have become young. Photo: Jerzy Strzeleck respectively,21 leaving less than less available.22,23 Carbonate ions penguin populations plummeted by 2,000 penguins today— the world’s are used by calcifying creatures 50–94% during a period of warmer smallest penguin population. such as plankton, corals, and clams ocean temperatures.18 to build their shells. As ocean Emerging threats acidification reduces carbonate ion •Likewise, researchers studying In addition to global climate change availability, these creatures will King penguins in the southern effects harming penguins, two become increasingly unable to Indian Ocean found that warm- emerging threats resulting from the build new shells and existing shells water events negatively impact world’s greenhouse gas pollution will begin to dissolve,24,25 which adult survival and breeding success, are gaining attention: leaves these animals with no way and they warn that King penguins to survive, and therefore, affects the are at extinction risk under future •sea level rise; and penguins’ food supply. warming scenarios.19 •ocean acidification. Although all oceans are affected by How is climate change affecting acidification, the Southern Ocean, Rising sea levels threaten to drown temperate penguins? and the upwelling systems where important coastal nesting sites for penguins live, will be among the first It may seem odd to think of penguins penguins—especially in places regions to be impacted. For example, living along the Equator at the where natural barriers like cliffs, at current rates of greenhouse Galápagos Islands or on the desert or human barriers like roads and gas emissions, the pteropod—a coasts of Africa and South America, developments, prevent penguins planktonic snail which forms a key but penguins are able to inhabit from retreating inland. places where upwelling brings cold, part of the food web in the Southern nutrient-rich ocean water to the Ocean—may be unable to survive surface, which creates a bountiful as early as 2030.26 The loss of the food supply. The penguins living pteropod will have profound impacts in these upwelling ecosystems on the Southern Ocean food web, periodically face extreme food and the penguins that depend on it.