Every spring, tens of thousands of plump, russet-breasted shorebirds drop down onto the wetlands of China’s Bohai Bay, ravenous after traveling 3,000 miles from Australia. This Yellow Sea stopover point is crucial for the birds, called red knots, to rest and refuel for the second leg of their journey, which will take them another 2,000 miles up to the Arctic tundra.
Unfortunately for the red knots, the intertidal flats of Bohai Bay are rapidly disappearing, cut off from the ocean by new sea walls and filled in with silt and rock, to create buildable land for development. In a society now relentlessly focused on short-term profit that seems like a wonderful bargain, and the collateral loss of vast areas of shorebird habitat merely an incidental detail. As a result, China’s seawall mileage has more than tripled over the past two decades, and now covers 60 percent of the mainland coastline. This “new Great Wall” is already longer than the celebrated Great Wall of China, according to an article published Thursday in Science, and it’s just getting bigger every year—with catastrophic consequences for wildlife and people.
“Reclamation” is what they still call it, a term dating from an era when pretty much everyone thought wetlands were useless, stinking, swampy places of no possible benefit to people. Oras an American writer put it in 1867, they “are for all practical purposes, worthless; and the imperative necessity for their reclamation is obvious to all, and is universally conceded.”
Of course, we now know better. Wetlands are among the richest and most diverse habitats on the planet. In China alone, more than 230 species of water birds—a quarter of the global total—depend on wetlands.
Besides the red knots (Calidris canutus), that includes endangered birds like the spoon-billed sandpiper and the Nordmann’s greenshank. Breeding habitat of the threatened Saunders’ Gull “is now almost entirely restricted to one part of one nature reserve,” said David Melville, a New Zealand-based ecologist and coauthor of the Science paper.
If sea walls enclose the last remaining coastal habitat of these survivors, it will likely push them to the brink of extinction. The precedents are ominous: In South Korea, for instance, more than 120,000 great knots (Calidris tenuirostris) used to stop to feed on their long-distance migration, according to Zhijun Ma, the paper’s lead author and a professor at the Fudan University School of Life Sciences. After a seawall went in, the population dropped to fewer than 30,000 birds.
But when a country is struggling to become part of the developed world, why should it worry about mudflats or birds? Wetlands worldwide provide an endless wealth of ecosystem services, from flood control and carbon storage to production of aquatic life. In 2011, China’s wetlands produced 28 million tons of seafood, about 20 percent of the world’s total, and also served as the nursery for countless aquatic organisms that are the base of the food chain for offshore fisheries. Wetlands also help buffer all those new developments from storm surges. Engineers like to argue that massive sea walls can protect developments in severe storms, and in certain circumstances that may be true. But after the 2004 Indian Ocean tsunami killed a quarter million people, researchers found that areas with intact mangrove wetlands had a much higher survival rate.
These benefits tend to be invisible, at least at first, but Ma and his co-authors estimate that in 2011, China’s wetlands produced $200 billion of ecosystem services, a significant chunk of the national economy. In the United States, our gradual recognition of this invisible money in the bank, and of the importance of wetlands for birds and other wildlife, has resulted in a “no net loss” of wetlands policy, and that’s helped to slow the centuries-long decline of wetlands. But in China, the immediate economic benefits of building on reclaimed wetlands continue to outweigh the long-term costs. Mayors and provincial governors are “basically judged on GDP growth,” said Melville. In the past few years the Chinese national government has begun to include measures of environmental performance alongside the economic metrics for evaluating the performance of local authorities.
But it still often looks to local officials as if they get the benefits now, while officials a generation or two down the line get stuck with any costs. So they often circumvent new regulations. For example, wetland projects over 124 acres require the approval of China’s central government. But “local governments simply divide large projects into smaller ones,” according to Ma and his co-authors. Or they quietly re-draw the boundaries of protected coastal reserves, freeing up wetlands to be filled in and “reclaimed.” Thus the rate of destruction of coastal wetlands is actually accelerating: 148,263 acres per year—an area almost three times the size of Boston—every year through 2020.
Red knots and other migratory birds pay the immediate price. They may travel across multiple countries that have protected wetland habitat, only to see a crucial stopover point destroyed in a country with less stringent environmental laws. The stopovers on China’s coast are especially important as feeding areas on major migratory routes.
Ma and his co-authors list several possible ways to curb the rate of reclamation, including a “no net loss” policy and the creation of an agency to coordinate the numerous government bodies that now oversee wetland management.
“There is some work being done in China at the moment to draw what they’re terming ‘red lines’ around areas of ecological importance and value,” said Melville, in an email. “Hopefully, that will mean that the sites are protected in some way.”
Part of the impetus for this change is the recent global attention to the air and water quality of China (in the news again this week because of the deadly haze now afflicting Beijing). But the environmental shift is still in its early stages. It may be years before the rate of seawall construction or wetland loss starts to slow. The question is whether the red knots and spoon-billed sandpipers will still be around to see it.