Shifting Baselines: Why the Environment Is Even Worse Off Than You Think

When it comes to the ocean, we don't know how good we used to have it.

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Mark Conlin via Getty Images

Bleached and dead coral in the Pacific Ocean

I had a chance to tag along this past weekend in Belize with a team from the Catlin Seaview Survey as they began their underwater assessment of the endangered coral reefs of the Caribbean. You can read about the project—which is using panoramic underwater cameras and machine vision to digitize the oceans—over here. It’s very cool stuff, done in conjunction with Google Earth.

As part of my reporting, I dove with the team in the waters above Glover’s Reef, which is part of Belize’s protected Hol Chan marine reserve. (I know, environmental reporters have a tough life.) The water was warm and blue, and the varied coral to my eye looked abundant and healthy, with intricate, boulder-size brain coral, jagged fire coral and majestic elkhorn coral. There wasn’t quite as much sealife as I’d been hoping to see, though  brilliantly-colored parrotfish swam among the coral, and I just missed glimpses of sea turtles and even a rare hammerhead shark. To me it was a beautiful dive, a gorgeous coral reef. It was what the oceans should be.

And it was nothing like it used to be. Coral cover in Glover’s Reef  dropped from 80% in 1971 to 13% in 1999. There’s been some recovery in the years since, thanks in part to the establishment of a large “no-take” protected area within the reef, and as a result Glover’s  is one of the healthiest coral ecosystems in the Caribbean. But that’s in many ways a reflection of how degraded the rest of the Caribbean—and coral reefs around the world—have become, thanks to pollution, coastal development, overfishing and climate change. Outside of parts of the South Pacific, too remote yet to be impacted by human activity, coral reefs are nothing like they used to be. The bewildering abundance, the sheer mass and variety of sealife that the first scuba divers would have encountered decades ago is long gone. We’re trying to protect a shadow of what once was—even though to me, floating among the coral of Glover’s Reef and straining for a view of that elusive hammerhead shark, it all seemed so perfect.

(MORE: Antarctica Melted in the Past, and As the Climate Warms, It’s Poised to Melt Again)

It turns there’s a scientific term for this feeling: shifting baselines. The fisheries scientist Daniel Pauly coined it in 1995 to describe how overfishing has changed the ocean so rapidly over the past several decades that what we think of as normal and healthy—the baseline—has had to shift to keep up with reality. Our picture of the environment becomes skewed, as we forget what used to be and adjust unconsciously to a diminished present.

Pauly explained the concept in a 2010 TED talk filmed on a  expedition to the Galapagos organized by the oceanographer Sylvia Earle—another trip I was lucky enough to be part of:

We transform the world, but we don’t remember it. We adjust our baseline to the new level,and we don’t recall what was there. If you generalize this, something like this happens. You have on the y axis some good thing: biodiversity, numbers of orca, the greenness of your country, the water supply. And over time it changes — it changes because people do things, or naturally. Every generation will use the images that they got at the beginning of their conscious lives as a standard and will extrapolate forward. And the difference then, they perceive as a loss. But they don’t perceive what happened before as a loss. You can have a succession of changes. At the end you want to sustain miserable leftovers. And that, to a large extent, is what we want to do now. We want to sustain things that are gone or things that are not the way they were.

Ocean science is particularly vulnerable to this effect because we still know so little about the state of the deep now—and even less about the way it was decades or centuries ago. Reliable global fishing statistics only go back to about mid-century, and it was only around the same time that scientists began to be able to explore the underwater oceans in depth. But underwater pictures and film from decades ago are rare, and there’s little hard, original baseline data—which is why that baseline shifts so easily. The best evidence of how the oceans have changed over that time period is found in the memories of the veteran scientists and divers who have actually seen the transition over the course of their lifetimes—people like Earle, who has been diving and studying the oceans since the 1950s, and Jeremy Jackson, a marine ecologist at the Scripps Institution of Oceanography. Jackson has studied the coral reefs around Jamaica for decades, and over that time, he’s seen that ecosystem destroyed by development and pollution. But someone diving today in Jamaican waters—and thousands of people do every year—would have no idea what they were missing, just as I can’t imagine what a pristine Glover’s Reef might have looked like decades ago. The present—diminished as it may be—is my baseline.

(MORE: Breaking the Waves: Catlin Seaview Survey Digitizes the Endangered Oceans)

That’s what makes the work of the Catlin survey so valuable. Over the course of several years, the group aims to build reliable, broad baseline data about the health of coral reefs around the world. That’s something that only became possible within the last few years, as underwater cameras became capable of taking thousands of pictures at a time and computer programs were written to analyze those images more than a hundred times faster than a human being could. The work is being done just in time—coral reefs have already degraded significantly, but as coastal population continues to grow and climate change takes its toll, coral will come under even more pressure in the future. By developing a firm baseline picture of the state of corals now, in 2013, we’ll have a reliable reference as they change in the future. The baseline will be fixed.

Still, I can’t help wondering if there’s a psychological value to shifting baselines. We live in an era of unprecedented and rapid environmental change—change that’s happening faster than our brains, which evolved over a period when stasis was the norm, might be able handle. By moving the baselines, by resetting our memories, we can cope with that change—with that decay, really. We can convince ourselves that the sea is clear, the coral is vibrant and it’s all not slipping away.

[UPDATE: Don’t end this piece thinking that the situation is entirely hopeless—though there’s been more environmental decline than most of us are aware of, actions can and have made a difference. A new study in Conservation Letters that looked at reefs in Belize found that instituting “no-take” policies in marine reserves can help make affected coral reefs much more resilient to future threats. Corals are six times more likely to regrow after a stressful event if parrotfish are protecting from fishing. Parrotfish are herbivores, and they keep seaweed in check that would otherwise crowd out growing corals. “If we ensure that corals are still able to regrow and reproduce, then even when they die, they’ll be able to replenish themselves,” says Peter Mumby, a coral ecologist at the University of Queensland in Australia and a Pew Marine Fellow who was the lead author on the paper. “It keeps the door open for adaptation.” Just because the baselines are shifting beneath our feet doesn’t mean that we’re helpless.]