Mystery of disappearing seals

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In a brightly lit room tucked among the rambling old buildings of the Bishop Museum, Ken Longenecker is sifting through a pile of tiny fish bones.

The zoologist’s task is tedious, and the smell from the bones — gleaned from the regurgitated meal of an endangered Hawaiian monk seal — can be vile. But the goal is one of the world’s most critical: rescuing an animal from extinction.

“These guys are on the brink, honestly,” Longenecker said as he explained a forensic challenge far more complex and desperate than what any TV writer could dream up.

Between the 1950s and early 1970s the monk seal population dropped unexpectedly by 50 percent. Now numbering somewhere around 1,200, the Hawaiian monk seal has failed to rebound despite efforts to protect its main habitat in the Northwestern Hawaiian Islands, the waters around which recently became a national monument.

The seals also have a developing but smaller outpost on the main Hawaiian Islands, where they are occasionally spotted by residents and tourists.

Among the seals’ most prominent problems are skinny pups that have trouble surviving through their first years. With the seals’ numbers projected to potentially plummet below 1,000 in the next five years, scientists are in a race to figure out why the shy, up to nearly 600-pound animals are disappearing from the islands.

“It’s really hard on an emotional level to know the clock is ticking,” said Jen Palmer, Conservation Scientist with the Bellevue, Wash.-based Marine Conservation Biology Institute.

Known in Hawaiian as “ilio holo i ka uaua,” or dog that runs in rough water, the seals’ English name is inspired in part by the animals’ solitary ways.

Monk seals broke off from the main evolutionary branch of seals about 12 million years ago and are believed to have since remained unchanged. Already the Hawaiian monk seal’s counterpart in the Caribbean is extinct. And the Mediterranean monk seal is estimated to number 500 at most.

With most of their lives spent in the water, much of the Hawaiian seals’ habits and even their main habitat along the remote string of islands extending some 1,400 miles across the Pacific Ocean have been a puzzle.

“In the marine environment, so much of what the animals do is a complete secret because you’re not quite sure where they’re going at any given time,” said Charles Littnan, foraging ecologist with the National Marine Fisheries Service’s Hawaiian monk seal research program.

A years-long investigation by the service, the Bishop Museum, the University of Hawaii, Dalhousie University in Canada and others is trying to find out what is happening to the seals.

Longenecker’s part of the project is to match bones found in their spew and scat to those in the museum’s collection of local specimens to figure out what the seals are eating.

The samples include bags of liquid feces and buckets of sun-dried seal throw-up brought back to the museum by researchers studying the seals during summers trips to the sparse, remote islands and keen-eyed passersby on the main islands.

While concerns remain for the Hawaiian seal regarding the potential for disease and deadly run-ins with discarded fishing gear, the study has put a particular focus on the seals’ nutritional struggles.

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.