Antarctic penguin count reveals dramatic decline

The number of chinstrap penguins in some colonies in Western Antarctica has fallen by as much as 77% since they were last surveyed in the 1970s, say scientists studying the impact of climate change on the remote region.

Emer McCarthy reports.

Researchers have found that a certain species of Antarctic penguin has seen a massive fall in its population.

Named for its distinctive black line underneath its head, the chinstrap penguin calls the Southern Pacific and Antarctic Oceans home.

But some colonies in Western Antarctica have shrunk by as much as 77% since they were last surveyed in the 1970s, according to the scientists from Northeastern and Stony Brook universities.

They traveled on two Greenpeace ships earlier this year, using manual and drone surveillance to assess the damage.

Reuters' Stuart McDill joined the crew.

(SOUNDBITE) (English) STUART MCDILL, REUTERS JOURNALIST, SAYING: "I'm on an island off the western Antarctic peninsula, and what's happened to the chinstrap penguin here is echoed up and down the continent.

Scientists simply can't tell us why-whether it's climate change generally, warmer average temperatures.

Or something more specific- the food supply, the krill they depend on.

What we do know for certain is that over the last 50 years more than half of the penguins that were here have disappeared." Steve Forrest is a conservation biologist.

(SOUNDBITE) (English) STEVE FORREST, CONSERVATION BIOLOGIST, SAYING: "The declines that we've seen are definitely dramatic.

Now, will they continue?

That's the question.

Are there enough krill, does the population stabilize?

There are plenty of chinstrap penguins in the world, they're not going to go immediately extinct in the next couple of decades.

We've got some very large populations to the east of us in the Weddell Sea.

So the issue is more what are these particular chinstrap penguins telling us about climate change, probably, and other drivers of global ocean change in this part of the Antarctic, where it's warming more dramatically than anywhere else; in the Antarctic, currently, five degrees C (Celsius) over the last 20 or 30 years." Greenpeace is calling on the United Nations to commit to protect 30% of the world's oceans by 2030, a target called for by scientists and a growing number of governments as the minimum needed to halt the damage being done by human activity.

(SOUNDBITE) (English) FRIDA BENGTSSON, OCEAN CAMPAIGNER, GREENPEACE, SAYING: "One might say that there is a lot to do; we have reached roughly around 4%, which is really, really low.

But looking at that, if you turn it around, it still means that we can actively use 70% of the world's oceans.

So it shouldn't be that big of a call really to protect unique places like we have here around us in Antarctica." The U.N.

Meets from March 23 to April 3 to try to agree a global ocean treaty next year.