One-Fifth of the Global Population Risks Malnutrition As Fish Stocks Decline

Coral reefs are under tremendous pressure from climate change, ocean acidification, and overfishing. A growing number are bleached a deathly white. This year has seen the worst global coral bleaching event since 1998, Nick Graham, a marine ecologist at Lancaster University, told me. (Coral bleaching happens when the water warms and colourful algae, called zooxanthellae, dies off. The coral dies if it gets bad enough.)

In some of the places where Graham works, like the western Indian Ocean, "we're recording 85 percent of corals bleached this year," he said. "We're not sure yet how many will die."

This coral die-off has huge implications, not just for plants and animals that rely on reefs, but for human populations too. In total, 1.39 billion people around the world—that's 19 percent of the global population—are vulnerable to nutritional deficiencies if fish stocks continue to decline. That's because fish makes up more than 20 per cent of their food intake by weight, says a commentary out Wednesday in Nature.

"Massive coral bleachings are affecting reefs substantially," William Cheung of the University of British Columbia's Institute for the Oceans and Fisheries, who's an author on that paper, told me. "With climate change, events like this are predicted to increase," putting millions of people who rely on fish stocks at risk.

Those most affected will be "in developing countries," Cheung added.

But, there's also reason to be hopeful. Graham and a team have completed a massive survey of over 6,000 reefs around the world, in 46 countries, and found something that's fairly surprising. Amid all this darkness, there seem to be some "bright spots," they say, where there are actually more fish thriving on the coral reefs than was expected.

It's not that these "bright spots" are perfectly pristine reefs far from human populations, or that they've somehow been spared the pressures of climate change. "The bright spots are outliers, punching above their weight," Graham explained. "They have way more fish than we'd expected." (They identified 15 bright spots globally, and 35 "dark spots," which are actually worse off than other areas.)

The important question is, why?

Turns out that handing over the management of fish stocks to local populations has a lot to do with it.

Around the bright spots, researchers saw strong "local involvement in [fisheries] management," Rashid Sumaila, director of UBC's Fisheries Economics Research Unit, told me. (He's a co-author on the coral reefs study, which is also out Wednesday in Nature.) "It's not just top-down. Governments can set the framework," he continued, "but they involve local people."

In other words, local fishers are given authority over the fish stocks they rely on. They also have incentive to protect these areas from illegal fishing, or poachers.

Sumaila points to Fiji as an example, where local management exists through traditional fishing "qoliqoli" areas. "They are really run by the villages," he told me, "So the villages know who has the right to fish, and where."

It's worth briefly telling the story of why, according to Graham, he and other scientists refer to these areas as "bright spots." It dates back to a 1990 project by Save The Children, he said. "They were interested in combating childhood malnutrition in Vietnam."

Save The Children focused on poor households—and pinpointed those where kids weren't actually malnourished, despite the poverty they faced. It turns out their parents were doing something different: crushing up little shrimps and crabs, gathered from the rice paddies, into their food, which gave them them another source of nutrition. They were also feeding their kids four smaller meals a day, instead of the more customary two.

One of the lessons here is that "local solutions were far more successful" than anything imposed from the top-down, said Graham, who added that the next step will be sending out teams of researchers—not just marine ecologists, but social scientists, economists, a whole range—to study the reefs where fish are doing relatively well, and figure out what, exactly, is going on in those places. Not just environmentally, but in the community, too.

Fish are critical to the health of the entire ecosystem, Graham said. "The more fish you have on the reef, the more likely it is to bounce back and recover from disturbances related to climate change." But we need fish to support local populations, too.

It turns out that giving people a hand in managing the resources they rely on, is likely one of the best ways we've got to support coral reefs.