In 2006, President George W. Bush sat down at a tiny table in the East Wing of the White House and signed a piece of paper that instantly created a truly massive national monument. It was larger than all the national parks combined, 46 of the 50 states, and the nation of Germany.

While some called it an environmental breakthrough, others grumbled that it didn’t really count as a park. That’s because unlike almost every other national monument to come before, it protected not land, but water.

The Northwestern Hawaiian Islands (tongue-twistingly renamed Papahānaumokuākea) Marine National Monument brought the concept of a “marine protected area” (MPA) into mainstream consciousness. Over the past couple of decades, governments across the world have scrambled to protect swaths of national waters from overfishing, oil extraction and other practices that damage the environment.

“MPAs started as kind an insurance policy against management failure in the ocean,” says Steve Gaines, dean of the Bren School of Environmental Science and Management at UC Santa Barbara. “It’s sort of like what we did on land. In the face of lots of human impacts, people eventually get to the point where they say, ‘Hey, we’ve got to set aside some of these natural places.’”

California is seen by most in this new field as a leader of MPAs. And while Hawaii might have the biggest park, no other place in the country has so effectively combined research and policymaking into a series of underwater parks. And no one in the world has done it so close to a heavily-populated coastline.

MPAs have been around for decades, but it was in the early 1990s that they really picked up speed in an organized way. Along with them came controversy. Fishermen, oil drillers and the shipping industry were afraid to lose access to parts of the ocean. No one was sure what to forbid or how to enforce it. And there was the question of whether they would even help sea life that much.

Regardless, in 1999, California took the plunge and created the Marine Life Protection Act. Previously, California’s protected waters were like most others — somewhat piecemeal, some barring fishing, others banning oil drilling. The Marine Life Protection Act essentially brought all these reserves under one roof and mandated a comprehensive plan to strategically protect the ocean resources of the state.

“It’s one thing to say we are going to create a giant no-take zone in the northwest Hawaiian Islands where you have like 15 fishing boats total,” says Gaines. “It’s an island out in the middle of nowhere. That’s fine, but what do we do in places where there are a lot of people?”

That is the genius and the challenge of the California system. It must balance the needs of the ocean with the needs of millions of users. To do that, the state has had to rely heavily on scientists like Gaines through a series of scientific advisory panels. This has given California’s ocean scientists — especially those at UC — a truly unprecedented opportunity to study, advise and shape marine protection.

As the years passed, scientists and policymakers began stitching together a series of protected areas — some of which are very strict, others less so. Very quickly, scientists realized that it wasn’t enough to just put aside a few or even a few hundred square miles of ocean.

“You may have a positive effect on the surrounding ecosystems. But beyond the distance that larvae go from that MPA, that MPA is having no effect on the rest of the state,” says Mark Carr, an ecologist at UC Santa Cruz. “The goal is not just to protect what’s within the protected area, but then presumably to have an influence outside the protected area as well.”

Carr, Gaines and many other UC scientists were active in the creation of the current network of California MPAs. The challenge now, they say, is to have the largest impact with a limited amount of protected area. The other challenge is to understand how MPAs can be good not only for the ocean but for the fishermen who depend on it.

“Do marine reserves compensate fishermen for lost fishing ground? That’s the fundamental question,” says, Ben Halpern, a UC Santa Barbara researcher in marine ecology and conservation biology.

After years of work, scientists now can say with confidence that creating an MPA increases the number of fish within its boundaries (presuming the MPA is designed correctly). But fishermen tend to collect along those boundaries, catching much of what swims out. Certainly we can’t just put the whole ocean under lock and key. So the question is, how can an MPA help both fishermen and the population as a whole? And how much do we need to protect?

In many ways, California’s is the perfect coastline to study MPAs. That’s because most of the fish that we eat don’t move all that far and can spend their entire lives in safety. However, out in the open ocean, sea life has to log a few miles in order to find food. Over the past few years, scientists across the world have begun thinking about something called a “pelagic” MPA, which would attempt to protect wandering species like sharks and tuna. If we thought protecting rockfish was hard, protecting tuna brings on a whole new level of complication.

“Tuna don’t even have a home range,” says Lou Botsford, a fisheries modeler at UC Davis. “[So far] we were protecting species with a home range of 5, 10 or 20 kilometers. These are species that range over thousands of kilometers.”

Botsford’s lab is in some ways the final destination for data collected by scientists like Gaines and Carr. He gathers mountains of information and tries to predict how certain fish will react to a given MPA. He says that although the scientific community is excited about pelagic MPAs, the challenges probably are too great for them to work. For one thing, it would require designating swaths of international waters the size of continents. It then would require enforcing those designations across national boundaries.

That is not to say that the lessons learned here in California need to stay here. As word has spread of the success of the California MPA system, countries like Britain, Ecuador, Costa Rica and Brazil have been anxious to invite UC scientists to share tips and results from the massive California ocean experiment.

Their perspective often can be crucial. Sara Maxwell (in photo at top), a research associate at UC Santa Cruz, says she was studying sea turtles at a MPA in Gabon when she saw something strange.

“We knew that there was this marine protected area in place. But we also knew that the bycatch and strandings were still incredibly high. One year I found more dead turtles than living turtles within the marine protected area,” she says.

The Gabonese had very few resources to enforce any kind of regulations. So Maxwell and her team isolated one region in the south, near the border with Congo, where the turtles congregated over just a couple of months in the fall. They advised the government to focus efforts in that region, during that time; as a result, the Gabonese were able to protect the turtles during a crucial period in their life cycle.

This doesn't mean that California scientists have a perfect understanding of how MPAs work in the ocean. In fact, they are just at the beginning. Botsford says that the most useful data from the California MPA network is only starting to come in. Once they have watched ocean populations ebb and flow for a decade, California may rewrite how the world protects its oceans.   

“In 10 years we’re going to have an unprecedented sense of how well these things work,” says Botsford. “It is something that the university has contributed to a lot. Not only us at UC Davis, but UC Santa Barbara, UC Santa Cruz  and UC San Diego as well.”