Fish counters in green rain slickers patrol a narrow channel of glacier-fed river, keeping close tabs on the thousands of salmon that migrate upstream to spawn.
Elsewhere along the coast, observation teams slosh through waterways in waders, carrying rifles to ward off aggressive bears. Still others monitor the migration from low-flying planes, or take inventory at fish weirs and atop counting towers placed strategically throughout the wilds of Alaska as part of an elaborate surveillance of returning fish.
At the first hint of a decline in salmon numbers, the Alaska Department of Fish and Game is quick to shut down coastal fishing grounds and order fishermen to pull in their nets and lines.
State officials do this without protest from fishermen. Rather, they work together, to protect not just a prized fish, but an economic bonanza and a leading source of private-sector jobs in the state.
"We don't want to catch fish this year, but in future years too," said Juneau fisherman Jev Shelton, who remembers when the collapse of Alaska's salmon fisheries from overfishing was declared a national disaster about 50 years ago.
Threatened with the loss of one of its top industries, Alaska began limiting the number of boats and fishermen, restricting the size of their catches, and giving fishermen a stake in the long-term viability of salmon and other fish.
If only the rest of the world had learned from Alaska's response to the crisis. Today, records show that 90% of the big fish — tuna, cod and swordfish — are gone from the oceans. If the serial depletions continue unabated, a group of scientists recently predicted, major seafood stocks will collapse by 2048.
Alaska's policy shifts are still an exception. By and large, ocean fishing, especially in international waters, remains a free-for-all with too many boats chasing too few fish.
Only about 6% of the global fish catch is certified as "sustainable," meaning that fish are not pulled from the ocean faster than they can reproduce and are not caught in ways that destroy other sea life or undersea habitat. Much of it comes from Alaska.
Though other U.S. regions and nations have been reluctant to rein in their fishing fleets, help has emerged from an unexpected quarter.
Wal-Mart Stores Inc. has pledged within three to five years to sell nothing but wild-caught seafood that meets standards for sustainability set out by the nonprofit Marine Stewardship Council. Founded in 1997, the council grants a blue and white label to fish that stand up to independent certification.
Wal-Mart's shift in policy has rippled through the global seafood trade. The National Fisheries Institute, the seafood industry's principal lobby, has become a booster of the sustainable seafood movement after years of resistance.
McDonald's is now nudging its suppliers to come up with sustainably caught fish for its Filet-O-Fish sandwiches, which consume 110 million pounds of Alaskan pollack, New Zealand hoki and other whitefish from around the globe.
Meanwhile, Darden Restaurants, the parent of Red Lobster, is taking similar steps, as is the Compass Group, America's largest food-service provider to corporate and university cafeterias.
In turn, commercial fisheries are seeking certification, for flounder caught off Japan, herring in the North Sea, Chilean hake and albacore off California.
"This is supply-chain pressure of the best kind," said Rupert Howes, chief executive of the London-based Marine Stewardship Council. "The Wal-Mart commitment is actually catalyzing commitments from other retailers around the world. We have a major Japanese retailer that wants to launch MSC-labeled products."
Yet there could be even more risks for precarious fish stocks as megagrocers such as Wal-Mart enter the seafood market, creating increased demand for the types of fish that the sustainable seafood movement is trying to save.
"That's what fundamentally undermines the market-based approach," said Daniel Pauly, a fisheries scientist at the University of British Columbia. "You create more customers for fish and invariably increase the pressure on the stocks."
Pauly and other critics believe it's too late for the market alone to protect fish when the world's population is growing and two-thirds of the world's commercial stocks are already being fished at or beyond their capacity.
The only solution to overfishing, they say, is for governments to muster the political will to restrict catches and take other measures to slow the plunder of the sea's diminishing bounty.
Much is at stake. Overfishing jeopardizes the dietary essentials of the billion people who rely on fish as their primary source of nonvegetable protein, and it threatens the health of the oceans themselves.
Fish and other marine animals help maintain the ocean's equilibrium by eating algae and keeping microbes in check. Overfishing abets the spread of these primitive organisms, which smother coral reefs and create "dead zones" in coastal waters that starve most sea life of oxygen.
Despite plummeting fish stocks, overfishing is accelerating around the globe, encouraged in part by $30 billion in annual subsidies for fishing boats, fuel and other assistance.
Asian and European nations provide the heftiest subsidies in efforts to keep a beleaguered industry afloat.
Subsidies and government inaction undermine efforts to give a rest to areas of the ocean so fish have a chance to replenish their populations.
S. Robson "Rob" Walton, son of Wal-Mart founder Sam Walton, was on a scuba-diving trip at Cocos Island off Costa Rica when one of the nation's leading conservationists persuaded him to join the sustainability movement.
Peter Seligmann, co-founder of Conservation International, had arranged the dive trip. During previous outdoor adventures, a friendship had evolved and with it $21 million in donations from the Walton Family Foundation for Conservation International's ocean programs.
After diving with schooling sharks and boating amid spinner dolphins, Seligmann told Walton that even a billionaire's generosity wasn't enough to prevent the impoverishment of the oceans.
"I was very clear with Rob," Seligmann said. "I said, 'I respect that you are dealing with philanthropy and your personal interest. We need to have a discussion with Wal-Mart. It is important for us to discuss with the world's largest retailer the issue of supply chain and the impact it has positively and negatively on the resources of the world.' "
Walton, who is a major Wal-Mart shareholder and chairman of its board of directors, agreed to introduce Seligmann to Wal-Mart Chief Executive H. Lee Scott Jr. A series of discussions led to a meeting in February at corporate headquarters in Bentonville, Ark.
There, company officials announced to a gathering of conservationists and seafood suppliers that Wal-Mart would switch to wild-caught seafood certified by the Marine Stewardship Council.
It also pledged to push for improvements in the way farm-raised shrimp and salmon, its two most popular items, are grown. Shrimp and salmon farms often spread pollution and disease to surrounding waters and contribute to the overfishing of wild fish, which are used to feed farm-raised stocks.
"We are the largest seafood retailer in the U.S.," said Peter Redmond, Wal-Mart's vice president for seafood and deli. "We have a pretty large footprint in everything we do. We have the kind of volume that could help a fishery make the move to sustainability."
McDonald's recently began taking similar steps after collapsing fisheries prompted it to look for ways to ensure a long-term supply for its 30,000 restaurants in 119 countries.
"We have seen fisheries dry up," said Bob Langert, McDonald's vice president for corporate social responsibility. "We want to make sure that we take actions within our supply chain to secure fish for the future. We want to have fish on our menu 10, 20 and 30 years from now."
Today, McDonald's has begun to shift away from rapidly dwindling stocks of Russian pollack to more sustainable sources, including the council-certified Alaskan pollack and New Zealand hoki.
Kellie McElhaney, a UC Berkeley business professor who studies corporate social responsibility, said a reform movement often gained stature when big companies decide to join.
"It ain't a church if you don't invite the sinners," she said.
For reforms to last, she said, corporations must see them as part of a business opportunity, such as gaining market share, customer loyalty or securing long-term supplies — as is the case with McDonald's.
"Anytime I hear a CEO saying, 'I'm doing it because it's the right thing to do,' I get nervous," McElhaney said. "It has to be part of the business strategy, such as helping people want Wal-Mart in their communities."
Today, the corporate sustainability movement affects millions of meals every day. But more than two-thirds of the world's seafood is consumed in China and other parts of Asia largely untouched by the movement to save fish stocks.
"It's really exciting," said Jane Lubchenco, a marine biologist at Oregon State University. "When Wal-Mart speaks, people listen. But it remains to be seen what kind of leverage that will bring on policy makers."
Success will come if these big buyers can change the political climate, said Mike Sutton, director of the Monterey Bay Aquarium's Center for the Future of the Oceans.
"The arm of the law is short, but commerce reaches everywhere," Sutton said. "If we can change the politics of fishing, it will make good management of fishing politically feasible."
In the United States, the politics are dominated by eight federal fishery management councils, quasi-governmental entities that were set up in the 1970s to help expand the domestic fishing fleets and divvy up the spoils.
The councils, which are controlled by fishing industry representatives, are not inclined to reverse course and begin shrinking the size of fleets to allow fish populations to recover.
Over the years, as fishermen struggled to stay in business amid declining fish stocks, the councils have urged raising the limits on allowable catches — even as government and university scientists warned that such exploitation was like a farmer eating his seed corn.
In that environment, the cod fishery off New England collapsed, as have some species of rockfish off California.
Although many scientists and two national commissions have spelled out needed changes, little has occurred.
Still, the climate of permissiveness in the United States doesn't compare with the free-for-all on the high seas or off the shores of poor nations that sell fishing rights to foreign ships.
Occasionally, progress on the policy front has been made.
Disregarding industry objections, President Bush earlier this year established the world's largest marine reserve around the northwest Hawaiian Islands. Such reserves act as fish nurseries, and scientists say a global network of them is needed to help depleted stocks rebound along with the health of the oceans.
Scientists say governments also need to reduce fishing pressure around the reserves. One way is to thin fleets by buying out boats and licenses. Another is to allocate an overall catch limit among fishermen and let them buy and sell shares, creating an economic incentive for some to quit fishing.
Experts say lasting reform is impossible until fishermen, like those in Alaska, are persuaded that short-term sacrifice ensures the long-term health of fish stocks.
In Alaska, the culture of reform did not take hold until after years of emergency closures of fishing grounds, idled boats, foreclosed loans and bankruptcies. Some fishermen lost their livelihoods.
"If there are no rules, then fishermen end up their own enemies," said Juneau's Jev Shelton, who is 64 and in his 46th year as a commercial fisherman. "That's what happens when you have unfettered access to a fishery. Human nature will bring unfortunate results."
Alaska voters in 1972 changed the state constitution to "limit entry" into any fishery for conservation purposes or to prevent economic distress among fishermen. The state has since kept salmon fleets from growing too large by restricting the number of permits.
Today, salmon catches are setting records — results that fishermen attribute to a new ethic of restraint. Fishermen see that they share the responsibility for the health of fish stocks, a dramatic shift from the short-term frenzy to catch as much as possible by any means necessary.
"We were all criminals at one point," said Scott McAllister, a purse seiner who has fished Alaskan waters since 1971. "You wouldn't turn in anybody, if they were your buddy or not.
"But now, it's self-policing."
McAllister, to his horror, recently realized he had violated the rules. Misreading a notice, he fished in a newly closed area.
"It was a honest mistake, but I couldn't live with myself," McAllister said. He turned himself in, forfeiting $12,000 worth of fish to state authorities.
About this story
This is one in a series of Los Angeles Times articles on threats to the world's oceans. To read the series "Altered Oceans" and see a multimedia presentation, including photo galleries and video reports, go to latimes.com/oceans.
What you can do to help
Everyone, especially seafood eaters, can help support healthier oceans by making even slight changes in what you buy and eat, and how you live.
Ask questionsAsk questions when buying fish at a store or in a restaurant. Where is it from? How is it caught? Customers' questions will force markets to get the answers.
Get educatedGet educated about seafood choices. The Monterey Bay Aquarium and other nonprofit groups offer helpful pocket guides to avoid overfished species and destructive fishing practices. Websites for specifics: http://www.seafoodwatch.orgwww.blueocean.org/seafood http://www.oceansalive.org
Shop for sustainabilityLook for the blue and white label from the Marine Stewardship Council for fish certified as sustainably caught.
Eat lower on the food chainEat more oysters, scallops, crabs and squid, and less swordfish, grouper, tuna and shark. Shellfish and other species low on the food chain reproduce much faster than slow-growing big fish.
Avoid buying seashellsMany of these animals are hunted for their shells, accelerating their decline.
Support protected areasSupport the creation of marine protected areas. The ocean equivalent of wildernesses, protected areas ban fishing and allow depleted species to recover.
Target abundant speciesIf you go ocean fishing, target species that are abundant, and avoid those that are overfished or poorly managed, even if it's legal to catch them.
Hang on to fishing gearDon't toss your fishing gear, including snarled lines. Discarded line and other gear can trap birds, turtles and marine mammals and cause them to drown.
Sources: Monterey Bay Aquarium; Seafood Choices Alliance; "50 Ways to Save the Ocean" by David Helvarg; Environmental Defense; Marine Stewardship CouncilCopyright © 2015, Los Angeles Times