FAGATELE BAY, AMERICAN SAMOA » It is what the coves of Oahu must have resembled a century ago: a place teeming with rich, healthy, diverse marine life, where the sea floor remains visible 60 feet down.

Hokule‘a and Hikianalia voyaging canoe crews ventured to the pristine, federally protected waters of Fagatele earlier this week mainly because the winds didn’t let them sail to a marine preserve in the Phoenix Islands, several hundred miles to the north, as planned.

But their “plan B” expedition in American Samoa turned out surprisingly well. The crews discovered a local sanctuary system that’s tried in recent years to better connect with the village communities, and whose approach is very much in tune with the Malama Honua “Care for the Earth” worldwide voyage.

“They seem to be incorporating local culture, which should be No. 1. You should start from there,” Hikianalia watch captain and Office of Hawaiian Affairs Papahanaumokuakea program specialist Brad Wong said of the National Marine Sanctuary of American Samoa. The local agency oversees some 13,500 square miles of protected waters in the South Pacific.

Fagatele Bay, with nearly 170 recorded coral species, 272 fish species and other biodiversity, represents just a quarter square-mile of those waters. It’s the one spot in the American Samoa marine sanctuary system that’s “no-take,” prohibiting any kind of fishing whatsoever.

Other areas permit sustenance fishing for local residents or some limited types of commercial fishing, local sanctuary officials say.

“I really like what they’re doing, especially being all the way out here,” Wong said.

Being “all the way out here” does present certain challenges, however — mostly enforcing the fishing restrictions with only a minimal U.S. Coast Guard presence in the territory, officials say.

“We’re so far, we’re so remote” — and local officials need more help to give enforcement “real teeth,” local National Marine Sanctuary Deputy Superintendent Atuatasi Lelei Peau said Thursday. The sanctuary has relied on partnerships with other agencies in the area such as the National Park Service and the U.S. Fish and Wildlife Service to help keep an eye on things, he said.

The situation is similar to some of the concerns raised in August during a public hearing held in Honolulu over President Barack Obama’s proposal to expand the Pacific Remote Islands Marine National Monument. Several local fishermen testified that the expansion would remove longliners and other fishing vessels that typically watch for any boats fishing illegally there. They further questioned whether federal agencies could sufficiently patrol the vastly expanded area in place of those boats.

On Thursday, Obama moved ahead with the plan, signing a memorandum expanding the monument to cover 490,000 total square miles and making it the largest marine preserve in the world. The move bans commercial fishing, deep-sea mining and other extraction of underwater resources. Recreational fishing will continue to be allowed — partially in hopes that it will help keep some boats present there. The expansion aims to protect millions of sea birds, turtles and marine mammals.

Meanwhile, back in American Samoa, Peau said that he’s seen commercial vessels fishing illegally at night during at least two of his three visits in the past several years to the national monument at Muliava, also known as Rose Atoll. That site represents the vast majority of the 13,500 square miles that the American Samoa marine sanctuary office oversees, and commercial fishing is prohibited there.

Many local residents either don’t have access to or aren’t aware of the pristine places in the waters that surround them, Peau said, so the sanctuary has focused much of its recent energy on community outreach to explain the benefits of protecting those areas.

The American Samoa National Marine Sanctuary opened a public ocean center in Pago Pago Harbor two years ago that’s already recorded 17,000 visitors (the entire island has a population of 55,000).

The local sanctuary office is also pushing to turn its six sanctuary sites into tourism destinations that would help create job opportunities in the nearby villages in addition to sustaining marine resources for the future.

“You’re not just protecting marine biodiversity, you’re also protecting people and place,” said Gene Brighouse, superintendent of the National Marine Sanctuary of American Samoa.

The preserves in American Samoa and the central Pacific are among several major sanctuary systems emerging in the world’s largest ocean.

For example, the Phoenix Islands Protected Area, governed by the Republic of Kiribati and established in 2008, covers more than 157,000 square miles of ocean about halfway between Hawaii and Fiji and is poised to enact tight restrictions against fishing in those waters in 2015.

Such preserves could help protect migratory fish species, including tuna, whose numbers have decreased by as much as 90 percent on average in recent decades due to industrial, some studies have shown.

Even the most ardent backers of more marine conservation zones say that they won’t go far enough unless they eventually connect — forming a corridor for these coveted, migratory fish species to safely travel across vast ocean distances without getting picked off by fisheries in between.

Some key Pacific Island nations have started talking about forming such corridors.

At the Pacific Islands Forum held this past summer in Palau, some member states started a connectivity study to see where corridors might work best to help better protect tuna and other pelagic fish stocks, said Bob Richmond, director of the University of Hawaii’s Kewalo Marine Laboratory.

About 3 percent of the world’s oceans is under some form of protection — but that number should eventually expand to about 20 percent to keep ocean resources healthy and stable, according to Greg Stone, executive vice president and chief scientist for the nongovernmental agency Conservation International.

But Stone said he’s also seen an “interesting turning point” in the public’s awareness of marine conservation issues in the past five years or so, and that it’s starting to transform into political action.

“Leaders are sensing a moment where oceans are coming to the center point,” he said earlier this month. “The oceans agenda has risen.”

The Associated Press contributed to this report.