In 2006, filmmaker Jean-Michel Cousteau, son of the explorer Jacques Cousteau, screened his documentary, Voyage to Kure, about the waters northwest of Hawaii. The theater was the White House and his audience was President George W. Bush. 

Bush was apparently moved by the images of rare sea turtles, sharks and coral, so moved in fact that within months he used his executive authority to protect a patch of ocean, called Papahānaumokuākea. It's an area almost the size of Montana and, at the time, was the world's largest fully protected marine reserve. 

“It’s an area like a national park, it’s an area that’s closed off to commercial extraction and fishing,” said Matt Rand, who directs the Global Ocean Legacy Project with the Pew Charitable Trusts. “And it’s an opportunity for that area to recover and become a healthy ecosystem.”

In the past decade, Rand’s group has helped the US and other governments protect almost a million square miles of ocean. The United Kingdom currently manages the world's largest fully protected marine reserve in the Indian Ocean, around the Chagos Islands, an area roughly the size of France. Earlier this summer, the Obama administration announced that it would create the largest reserve yet — in US waters in the south Pacific.

When Rand looks at the globe, he still seesa lot more ocean that needs help. It’s tough work convincing governments to protect their seas. It can be even harder to keep vast areas in the middle of the ocean safe.

“No question about it, they are huge challenges,” said Rand. “We’ve been looking into the satellite technologies and actually starting to use satellite technologies to help monitor those waters. So we’ve actually been able to identify vessels that are engaged in illegal fishing activity in a number of the different locations in which we’re working.”

Spotting an illegal fisherman is the easy part though. Then authorities have to get a ship out there to nab them. It’s only a crime if you get caught, right?

Pew Charitable Trusts

But Rand said just the act of declaring an area a marine reserve helps.

“If you’re an illegal fisherman out there, let’s say around the waters of Palau, and the Palau president announces that his waters are a marine sanctuary and if you enter into them, we now have new strict fines and we’re going to confiscate your vessel. There’s automatically a deterrent.”

Let’s cut to the chase: Does it work? Consider Papahānaumokuākea.

“I think it, like other marine areas, were closed as a risk-prevention action,” said University of Rhode Island oceanographer Jeremy Collie. “It wasn’t a particular activity that was going on that was of concern.”

Thus, it's hard to evaluate the success of the marine reserve. Still, Collie added, it’s good to get ahead of the curve. Think of Yellowstone National Park in 1872 — Congress and President Ulysses S. Grant preserved the area not to stop plundering, but to prevent it. 

With oceans today, Collie said governments need to make a choice.

“These are economic allocation decisions. But there are certain values, wildlife values, that are very difficult to quantify. That’s where people’s own values come into play,” Collie said.

Those values differ for different people, of course.

“When you try and protect anything, it seems that there are always people that are unhappy with that,” said Rand. “We have lots of fisherman that are not happy with this idea. There are those that are interested in deep sea minerals that oppose the idea of fully protecting areas.”

Still, Rand is steadfast: There’s a strong argument for doing more, a lot more.

“We have scientific reports that indicate 90 percent of the large predatory fish, like sharks, tuna, sword fish, cod, have already been depleted,” Rand said. “Most people are really not aware that our oceans are in a critical situation, they’re in a severe decline.”

Besides supporting marine life, healthy oceans also suck greenhouse gasses from the atmosphere and support tourism.

The Obama administration says it will decide this fall exactly where and how big that new South Pacific marine reserve will be. Rand wants the administration to go big. He cites scientific research calling for the protection of 30 percent of the world’s oceans. They’ve got a ways to go. So far, Pew has helped protect close to a million square miles of ocean, impressive no doubt, but equivalent to about 1.5 percent ofjust the Pacific Ocean

From PRI's The World ©2015 Public Radio International