Some Oahu soldiers out for a bit of exercise ended up rescuing a threatened green sea turtle.

The members of Fort Shafter’s 8th Theater Sustainment Command were kayaking in the Anahulu River on the North Shore on Monday when they noticed something unusual: a crab trap buoy bobbing aggressively. After padding closer, they saw a young sea turtle was tangled in the net underwater.

Spc. Henry Caldera and Sharon Nakai, an instructor with the Army’s Family and Morale, Welfare and Recreation Programs, could see the net was strangling the turtle when they lifted it into a kayak.

"We thought it was going to die," Caldera said, according to a news release from the unit. The soldiers freed the turtle, which weighed about 35 pounds.

"He took three nice gasps of air when we cut the netting away from his neck," said Caldera, of the 643rd Company, 84th Engineering Battalion, 130th Engineer Brigade.

"He calmed down quickly," he said.

Outdoor recreation program coordinators called the National Oceanic and Atmospheric Administration’s stranded sea turtle hotline. NOAA staff arranged to pick up the rescued turtle nearby.

They released the animal Tuesday after removing some more crab line netting and taking care of it overnight. It was about 10 to 15 years old, they estimated.

Known as honu in Hawaii, green sea turtles are found around the world in tropical and subtropical waters. They nest on beaches in 80 countries.

In 1978 the U.S. government listed those that breed in Florida and Mexico’s Pacific coast as endangered. It classified all others, including those in Hawaii, as threatened.

Local honu have been recovering, however.

A 2007 NOAA review found Hawaii’s green sea turtle population has been growing at a rate of 5.7 percent per year for the past three decades.