Fw: World Science: Penguin populations falling steeply, biologist warns

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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)

 

 

 

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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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