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Penguin populations falling steeply: biologist

July 1, 2008
Courtesy University of Washington
and World Science staff

Like the pro­ver­bi­al ca­nary in the coal mine, pen­guins are sound­ing the alarm for po­ten­tially cat­a­stroph­ic changes in the world’s oceans, a Uni­ver­s­ity of Wash­ing­ton bi­olo­g­ist says.

The cul­prits are glob­al warm­ing, oil pol­lu­tion, de­ple­tion of fish­er­ies and ram­pant coast­line de­vel­op­ment, which threat­en breed­ing hab­i­tats for many pen­guin spe­cies, she ar­gues.

Rain has soaked this Adé­lie pen­guin chick in Ant­arc­ti­ca be­fore its feath­ers are ca­pa­ble of re­pel­ling wa­ter. Though the icy con­ti­nent is in es­sence a des­sert, coast­al rain­fall is be­com­ing more com­mon with chang­ing cli­mate. (Cour­te­sy Dee Boersma)
These fac­tors are be­hind rap­id popula­t­ion de­clines among the birds, said the uni­ver­s­ity’s Dee Boers­ma, an au­thor­ity on pen­guins. 

“Pen­guins are among those spe­cies that show us that we are mak­ing fun­da­men­tal changes to our world,” she said. “The fate of all spe­cies is to go ex­tinct, but there are some spe­cies that go ex­tinct be­fore their time and we are fac­ing that pos­si­bil­ity with some pen­guins.”

In a pa­per pub­lished in the July-August edi­tion of the re­search jour­nal Bio­Science, Boers­ma notes there are 16 to 19 pen­guin spe­cies, and most pen­guins are at 43 sites, vir­tu­ally all in the South­ern Hem­i­sphere. 

For most of these col­o­nies, po­pu­la­t­ion trends have been un­clear, so few peo­ple real­ized that many pen­guins were suf­fer­ing sharp popula­t­ion de­clines, Boers­ma said. She ad­vo­cates an in­terna­t­ional ef­fort to check on the larg­est col­o­nies of each pen­guin spe­cies at least eve­ry five years.

Work­ing with the Wild­life Con­serva­t­ion So­ci­e­ty and col­leagues, Boer­sma has stud­ied the world’s larg­est breed­ing col­o­ny of Mag­el­lanic pen­guins at Pun­ta Tombo on Ar­genti­na’s At­lan­tic coast. That popula­t­ion probably peak­ed at about 400,000 pairs be­tween the late 1960s and early 1980s, and to­day is half that, she said.

There are si­m­i­lar sto­ries from oth­er re­gions. Af­ri­can pen­guins de­creased from 1.5 mil­lion pairs a cen­tu­ry ago to just 63,000 pairs by 2005, Boersma claimed. Galapa­gos Is­lands pen­guins, the only spe­cies whose range ex­tends in­to the North­ern Hem­i­sphere, now num­ber around 2,500, about a quar­ter of what their popula­t­ion was when Boers­ma first stud­ied them in the 1970s.

Boersma re­counts watch­ing in 2006 as cli­mate anoma­lies wreaked hav­oc on the same popula­t­ion of Em­per­or pen­guins fea­tured in the pop­u­lar 2005 film “March of the Pen­guins.” The col­o­ny bred in the same place as in oth­er years, where the ice is pro­tected from the open sea and wind keeps snow from pil­ing up and freez­ing the eggs. But in Sep­tem­ber, with the chicks just more than half-grown, the adults ap­par­ently sensed dan­ger and un­char­ac­ter­is­tic­ally marched the col­o­ny more than three miles to dif­fer­ent ice. 

The ice they chose re­mained in­tact the longest, but in late Sep­tem­ber a strong storm broke it up and the chicks were forced in­to the wa­ter, Boersma said. While the adults could sur­vive, the chicks needed two more months of feath­er growth and build­up of in­su­lat­ing fat to be in­de­pend­ent. The likely re­sult, Boers­ma said, was a to­tal col­o­ny­wide breed­ing fail­ure that year.

Glob­al warm­ing al­so ap­pears to be key in the de­cline of Galapa­gos pen­guins, she said: as the at­mos­phere and ocean get warm­er, El Niño South­ern Os­cilla­t­ion events, which af­fect weath­er world­wide, seem to oc­cur more of­ten. Dur­ing those times, ocean cur­rents that car­ry the small fish that pen­guins eat are pushed far­ther away from the is­lands and the birds of­ten starve or are left too weak to breed.

These prob­lems raise the ques­tion of wheth­er hu­mans are mak­ing it too hard for oth­er spe­cies to co­ex­ist, Boers­ma argued. Pen­guins in places like Ar­gen­ti­na, the Falk­lands and Af­ri­ca run ris­ing risks of be­ing fouled by oil, ei­ther from ocean drill­ing or be­cause of pe­tro­le­um dis­charge from pass­ing ships, she con­ti­nued. The birds’ chances of get­ting oiled are al­so ris­ing be­cause they often have to for­age much far­ther than be­fore to find prey.

“As the fish hu­mans have tra­di­tion­ally eat­en get more and more scarce, we are fish­ing down the food chain and now we are be­gin­ning to com­pete more di­rectly with smaller or­gan­isms for the food they de­pend on,” she said. As the world’s popula­t­ion con­tin­ues to ex­plode and more and more peo­ple live in coast­al ar­eas, the neg­a­tive ef­fects are grow­ing for both ma­rine and shore-based hab­i­tats used by a va­ri­e­ty of spe­cies, Boer­sma added.

“I don’t think we can wait. In 1960 we had three bil­lion peo­ple in the world. Now it’s 6.7 bil­lion and it’s ex­pected to be eight bil­lion by 2025,” she said. “We’ve waited a very long time. It’s clear that hu­mans have changed the face of the Earth and we have changed the face of the oceans, but we just can’t see it. We’ve al­ready waited too long.”

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Like the proverbial canary in the coal mine, penguins are sounding the alarm for potentially catastrophic changes in the world’s oceans, a University of Washington biologist said. The culprits are global warming, oil pollution, depletion of fisheries and rampant coastline development, which threaten breeding habitat for many penguin species, she argues. These factors are behind rapid population declines among the birds, said the university’s Dee Boersma, an authority on the flightless birds. “Penguins are among those species that show us that we are making fundamental changes to our world,” she said. “The fate of all species is to go extinct, but there are some species that go extinct before their time and we are facing that possibility with some penguins.” In a paper published in the July-August edition of the research journal BioScience, Boersma notes there are 16 to 19 penguin species, and most penguins are at 43 sites, virtually all in the Southern Hemisphere. For most of these colonies, population trends have been unclear, so few people realized that many penguins were experiencing sharp population declines, Boersma said. She advocates an international effort to check on the largest colonies of each penguin species at least every five years. Working with the Wildlife Conservation Society and colleagues, Boersma has studied the world’s largest breeding colony of Magellanic penguins at Punta Tombo on Argentina’s Atlantic coast of Argentina. That population probably peaked at about 400,000 pairs between the late 1960s and early 1980s, and today is half that, she said. There are similar stories from other regions. African penguins decreased from 1.5 million pairs a century ago to just 63,000 pairs by 2005, Boersma claimed. Galapagos Islands penguins, the only species whose range extends into the Northern Hemisphere, now number around 2,500, about a quarter of what their population was when Boersma first studied them in the 1970s. Boersma recounts watching in 2006 as climate anomalies wreaked havoc on the same population of Emperor penguins featured in the popular 2005 film “March of the Penguins.” The colony bred in the same place as in other years, where the ice is protected from the open sea and wind keeps snow from piling up and freezing the eggs. But in September, with the chicks just more than half-grown, the adults apparently sensed danger and uncharacteristically marched the colony more than 3 miles to different ice. The ice they chose remained intact the longest, but in late September a strong storm broke it up and the chicks were forced into the water, Boersma said. While the adults could survive, the chicks needed two more months of feather growth and buildup of insulating fat to be independent. The likely result, Boersma said, was a total colonywide breeding failure that year. Global warming also appears to be key in the decline of Galapagos penguins, she said: as the atmosphere and ocean get warmer, El Niño Southern Oscillation events, which affect weather worldwide, seem to occur more often. During those times, ocean currents that carry the small fish that penguins eat are pushed farther away from the islands and the birds often starve or are left too weak to breed. These problems raise the question of whether humans are making it too hard for other species to coexist, Boersma said. Penguins in places like Argentina, the Falklands and Africa run rising risks of being fouled by oil, either from ocean drilling or because of petroleum discharge from passing ships. The birds’ chances of getting rising are also increasing because in many cases they have to forage much farther than before to find the prey on which they feed. “As the fish humans have traditionally eaten get more and more scarce, we are fishing down the food chain and now we are beginning to compete more directly with smaller organisms for the food they depend on,” she said. As the world’s population continues to explode and more and more people live in coastal areas, the negative effects are growing for both marine and shore-based habitats used by a variety of species, Boersma added. “I don’t think we can wait. In 1960 we had 3 billion people in the world. Now it’s 6.7 billion and it’s expected to be 8 billion by 2025,” she said. “We’ve waited a very long time. It’s clear that humans have changed the face of the Earth and we have changed the face of the oceans, but we just can’t see it. We’ve already waited too long.”