The Hawaiian monk seal population is about 1,200 worldwide, the lowest ever recorded.

Researchers have been making efforts to increase the number through a new captive care project at Midway Atoll that released six female monk seals last month.

Should efforts like these cease, researchers fear the number could drop below the key threshold of 1,000 worldwide.

"The Hawaiian monk seal population is in the worst shape it's ever been in," Robert Braun, a National Oceanic and Atmospheric Administration Fisheries contract veterinarian, said at a press conference yesterday.

Through this captive care project, monk seal scientists at the Pacific Islands Fisheries Science Center and several other partner agencies are trying to improve pup survival to increase the population growth rate.

80 PERCENT OF PUPS DIE

Currently, the chance a monk seal pup has to reach reproductive age is less than 20 percent.

The project started when researchers rescued twin Hawaiian monk seal pups in May 2006, which generated substantial public interest.

Last month, the twins, along with four other female monk seals, were released with satellite tracking devices that researchers — and now the public — can monitor.

A new Web site, launched by NOAA Fisheries, allows the public to track the movements and diving behavior of the six female monk seals. The site will be updated twice a week.

The goal is to raise awareness about the critically endangered species while satisfying the curiosity of people who want to know what happened to the twin pups — known as PO22 and PO26 — recovered last year.

"When they were released, we were really concerned about how they would react," Braun said. "But within a day or so, they were acting ... very normally. They're doing just fine."

Researchers collected female seals at weaning and supported them in shoreline pens.

BACK TO THE WILD

After the twin monk seals, which were severely underweight and malnourished, were rehabilitated at the Pacific Islands Fisheries Science Center's Kewalo Research Facility, they were returned to Midway Atoll in October 2006 and placed in a protective pen on Cargo Beach for further care.

Four other female pups were added to the pen, which straddled the beach and adjacent shallow water to create an authentic environment for the pups.

After up to 27 days of hand-feeding the monk seals, scientists began throwing high-calorie herring into the shallow water to encourage them to feed on their own. Soon the seals were demonstrating predatory behavior, Braun said, charging for fish that accidentally got into the pen.

"Anything that swam through was fair game," he said.

On March 19, the twins were released on the northeastern side of Eastern Island, one of the three islands that make up Midway Atoll.

At first, the twins hesitated to leave their cages. "They weren't quite sure if they were ready to give up their free lunch," Braun joked.

But as soon as the two females hit the water, they took off, Braun said.

"So far it's looking very successful," said Charles Littnan of NOAA's Pacific Islands Fisheries Science Center. "The animals are behaving normally, and we're very happy about that."

Through the project, researchers hope to find better and more effective ways to grow the dwindling population and save the monk seals from extinction.

"We want to expand this project into a larger program in the future so we can really make an impact on the population," Braun said.

Reach Catherine E. Toth at ctoth@honoluluadvertiser.com.