Hawaiian monk seals 'on brink' of extinction

Not enough food
Each of the Hawaiian monk seals' six main sub-populations in the islands has its own challenges, including sharks preying on young seals at the animals' largest home base along French Frigate Shoals. But all the populations are unified by one factor — they're not getting enough food, Littnan said.

The big questions that need to be answered include: How is the seals' environment affecting their diet? Are other species of predators beating them to their prey? Is a large scale environmental change knocking the seals out of their ecological niche? And what has been the role of people in the seals' struggles?

Finding answers is made particularly difficult by the bounty of the ocean surrounding the islands.

While most seals in colder waters prey chiefly on about five species, the Hawaiian monk seals' diet appears to incorporate 28 species of cephalopods — squids and similar animals — alone, Littnan said.

That diversity makes Longenecker's job tough and slow-going. It is also complicated by the fact that the visual markers, such as spines and color, usually used to identify a species are often gone once he receives the sometimes weeks or months old specimens.

"I feel pretty good about myself when I figure out which species has been eaten," said Longenecker on a recent day when he was contending mostly with the remains of a tangle of eels but had also been able to separate out parts of a few fish, such as the head of a scorpionfish.

In three years of work, he still can't classify about 5 percent of the fish remains he's seen even within a family of fish.

Beetles help out
To expand his ability to identify more of the samples, he has been working to broaden the museum's collection by bringing in new specimens. The month-long identification process includes drying the whole fish and then placing it in a box with carrion beetles to gently remove the flesh and reveal the bones underneath.

Meanwhile Longenecker consults with the researchers trying to unravel the seals' diet by analyzing the fatty acids found in small biopsies of seal blubber. And the animals continue to be tracked for their behavior and watched for disease and signs of contamination from pollutants.

"Every person takes a very tiny bit of the puzzle and you hope at some point you ... put it all together and it makes a pretty clear picture," said Littnan, who expresses some hope for the seals' future.

"Some people throw out the term 'evolutionary dead end.' ... I think that's an easy out to say that. It's kind of a giving up sort of statement," Littnan said.

The seals themselves have at least implemented one lifestyle change on their own.

There are no recorded births on the main Hawaiian islands until the 1990s. Now about 10 pups are born each year here, where sharks and other natural competitors for prey are more scarce. Thirteen pups have been born in 2006 so far, mostly on Kauai.

MORE FROM ENVIRONMENT

Environment Section Front

South Africa will sell ivory to Japan, China Scientists confirm shark's ‘virgin birth’ Canada faces suit over killer whales Court wrangles over Navy sonar, whales N.J. to 'race to the sea' for wind power Orphaned rhino adopted by park rangers Study: Arctic stormier as Earth warms EarthTalk Q&A: Painkillers, electric bikes Deadlines set for polar bear habitat Geothermal energy backers expect rebirth Environment Section Front   Add Environment headlines to your news reader: