WAILUKU » Green sea turtles are making a comeback in the Hawaiian Islands thanks primarily to 31 years of protection under the federal Endangered Species Act, scientists and observers said.

And they also said hawksbill turtles are showing positive signs, as well.

“;The green sea turtles are well on the road to recovery,”; said George Balazs, a sea turtle biologist with the National Marine Fisheries Service.

Studies by Balazs and Mililani Chaloupka show a fourfold increase in nesting numbers of green sea turtles in the French Frigate Shoals in the Northwestern Hawaiian Islands during about a 30-year period.

Balazs said the hawksbill turtle population is still small but has shown signs of increasing breeding activity on Maui and the Big Island.

Commercial exploitation was the major cause of the decline of the green sea turtles and hawksbill turtles worldwide, although many nations have agreed to halt the importation of the shells, federal officials said.

A hawksbill shell commands high prices. The shell and other parts of the turtle were used for jewelry, leather, oil, perfume and cosmetics.

The Endangered Species Act of 1978 lists green sea turtles, or Chelonia mydas, as threatened in the Hawaiian Islands and hawksbill turtles, or Eretmochelys imbricata, as endangered, prohibiting the public from harming or harassing them.

Satellite studies of migration patterns show hawksbill turtles traveling within the Hawaiian Islands only and are mainly found in southeastern Hawaii and various parts of Maui, including Hana, Lahaina, Oneloa and Maalaea.

State aquatics biologist Skippy Hau said the Valley Isle witnessed a high level of breeding activity for hawksbills in 2008.

“;I think last year was an exception, having eight to 10 nests—that's a record in current times,”; Hau said.

In 2003 there were no hawksbill nests found on Maui.

Hau said the increase in nesting activity represents a shift from the 1990s, when two female hawksbill turtles searching for a nesting area were killed after crawling from the ocean and trying to cross North Kihei Road.

Government officials and volunteers built fences along the sand dunes at Maalaea to prevent turtles from crossing the highway.

Hannah Bernard, president of the Hawaii Wildlife Fund, said no turtles have been killed on North Kihei Road since the fences were installed.

Bernard said the hawksbills are still critically endangered and that the Hawaiian archipelago probably has fewer than 100.

She said her group is seeing more green sea turtles on Maui.

“;The greens are coming back in strong numbers,”; she said.