Climate Click

Penguins are in dire peril due to climate change and a resurgence of hungry whales, according to the results of a long-term study.

Back in the early 80s, about half of Adelie and chinstrap penguins on the West Antarctic Peninsula returned to their breeding grounds after hatching. That number has plummeted to just 10 percent today – the implication being that the AWOL penguins have starved to death.

Biologist Wayne Trivelpiece of the National Marine Fisheries Service, a researcher in the study who has been on the penguin case since the 1970s, thinks he knows what’s killing off the birds: a lack of krill. These tiny shrimplike crustaceans are a huge food source to young penguins, and without enough of them the creatures are essentially screwed.

So what’s causing the krill implosion? Trivelpiece et al cite two prime suspects.

The first is warmer temperatures over Antarctica. The average winter on the West Antarctic Peninsula has risen by 10 degrees since about 1950. Krill feed off of algae that accumulates on sea ice, and with warmer winters causing less ice their population drops sharply – about 80 percent since the mid-1970s, the researchers say. (It’s true that Antarctic ice increased during 2010, but any growth is expected to be temporary.)

Not everything is starving around the South Pole. Whales and seals have regained a little footing in the underwater food chain since the days when they were prey for widespread human hunting. These creatures are slurping up enough krill that it might actually be harming the penguins. Humans are eating them, too: Krill factors into several types of dietary supplements (Krill Oil)

So will the penguins be able to revert to their historical food source, fish? Maybe not, says Trivelpiece.