The state is investigating the killing of a green sea turtle found by beachgoers on Laniakea Beach near Hale'iwa yesterday morning.

The turtle, one of a group of 20 that regularly comes to bask in the sun on the beach commonly called "Turtle Beach," had its shell and head cut off and was missing a flipper, said Patrick Doyle, project coordinator for Malama Na Honu, a volunteer group of turtle guardians.

"It was slaughtered," Doyle said. "Her name was Honey Girl and she was a regular at Laniakea Beach.

"We were all in tears. She came up almost daily."

The 200-pound female sea turtle was found partially buried in the sand. She is thought to be about 30 years old, a turtle in the prime of her reproductive life.

The green sea turtle is considered an endangered species in Florida and the Pacific coast of Mexico and a threatened species in other areas such as Hawai'i, according to the Endangered Species Act. The sea turtles were included for protection in 1978.

On the Mainland, the green turtles nest along the central and southeast coast of Florida. Scientists estimate the female population ranges from 200 to 1,100 nesting annually.

Violations of the Endangered Species Act can bring penalties of up to a year in jail and a $50,000 fine.

Deborah Ward, a spokeswoman with the state Department of Land and Natural Resources, yesterday said the death is the first since a killing in 2003, when a 100-pound specimen was found with a noose around its neck on a Lahaina beach.

The turtle's body has been taken to the National Oceanic & Atmospheric Administration facilities, where scientists will perform a necropsy.

"She was killed by a human being," Doyle said. "Someone cut away her belly plate and removed the flesh. It was like someone opened her up like a tin can. It's very upsetting."

Malama Na Honu has a team of volunteers who go to Laniakea daily to educate the public and to erect barricades around the sea turtles that come on the beach to bask in the sun.

DLNR enforcement officers will work with NOAA officials during the investigation, Ward said. No suspects have been identified, she said.

Laura H. Thielen, DLNR chairwoman, said she wanted to thank Malama Na Honu for its guardianship over the sea turtles at Laniakea. "This is a shocking and distressing action," she said.