Exterminate first, ask questions later
The Economist 20 Apr 17;
KATHERINE LEUNG was hunting for birds—black-tailed godwits to be precise. Armed with a wide net, she stood at dusk amid the Mai Po Marshes, a wide expanse of mudflats, mangroves and shrimp ponds on Hong Kong’s border with mainland China, trying to nab a couple of birds as they came to roost after feeding. In her pocket were two tiny and expensive radio transmitters. An employee of the World Wide Fund for Nature (WWF), which manages Mai Po, she was hoping to affix them to the backs of two godwits heading north for the summer. By the time she gave up, at midnight, she had not caught any godwits, but she had snared three gorgeous greater painted snipe. She had also spotted an eagle owl out hunting and a leopard cat prowling nearby. She will be hunting herself again soon, as the godwits’ twice-yearly transit reaches its peak.
Astonishingly little is known about the godwits that arrive at Mai Po in full breeding plumage at this time of year—neither where exactly in the warmer parts of Asia they have wintered nor where, in the far north, they will breed. Most of the world’s migratory waterbirds barrel up and down one of eight big north-south “flyways”. The East Asian-Australasian Flyway, along which Mai Po is located, is the most rich in species. This spring 50m waterbirds will move from their winter homes in South-East Asia, Australia and New Zealand to their breeding grounds in Russia, Mongolia, northern China, the Korean peninsula, Japan and even Alaska. They rely on intertidal flats like those at Mai Po, teeming with nourishing molluscs, worms and crustaceans, as well as plants, to supply the food that fuels their journeys.
Of the eight big flyways, the East Asian-Australasian is also the one displaying the sharpest decline in the number of birds. Of its 155-odd waterbird species, at least 24 are now globally threatened. They include the diminutive spoon-billed sandpiper, a wader whose numbers are down to fewer than 200 pairs.
Transiting one of the world’s most dynamic industrial regions is clearly taking a toll. Asia’s migratory waterbirds face immense pressures, from hunting, pollution, ingested plastic and competition from aquaculture. But the biggest disaster is the destruction of coastal way-stations like Mai Po. Since 1950 China has lost over half its coastal wetlands to “reclamation”. According to the International Union for Conservation of Nature (IUCN), the Yellow sea, into which the Yellow river flows, has lost over 35% of intertidal habitat since the early 1980s. An especially destructive moment was the run-up to the Beijing Olympics of 2008, for which a lot of heavy industry was moved from the capital to the coast.
Xianji Wen, who, like Ms Leung, works for the WWF, describes the Yellow sea as a “bottleneck” for the whole flyway: so many waders pass through it that the loss of habitat there is particularly consequential. Four-fifths of Asia’s red knots, having wintered in Australasia, stop on their way north at one spot, Luannan, east of Beijing. The bar-tailed godwit flies non-stop from New Zealand to the Yellow sea—over 6,000km. After recovering there, the species flies non-stop again to its breeding grounds in the extreme north of Russia.
Populations of both species have crashed by over a third, probably because of coastal development. On the eastern side of the Yellow sea in South Korea, a huge reclamation scheme involving the world’s longest dyke destroyed Saemangeum, a 400 square kilometre tidal estuary. The 330,000 shorebirds that used to use the area did not move to other staging sites—there is a limit to how many birds even rich mudflats can support. Most simply died. In 2010 the IUCN reclassified the great knot from a species of “least concern” to “vulnerable”, thanks largely to that dyke. It might also prove the death knell of the spoon-billed sandpiper. The reclamation scheme, meanwhile, is doing far less for the local economy than its backers promised it would.
There is a silver lining, however. The vast middle class created by the region’s breakneck growth is becoming interested in conservation. Hong Kong has long had plenty of birdwatchers, and schoolchildren throng Mai Po’s education centre. In Taiwan a conservation movement was spawned by another critically endangered species, the black-faced spoonbill. In the 1980s its numbers fell to fewer than 300. It bred on a few islands at the western end of the Korean peninsula’s demilitarised zone and wintered at three sites: Mai Po, the Red river delta in Vietnam and Chiku in Taiwan. Taiwanese bird lovers first secured an end to hunting at Chiku and then, in 2000, fought off plans for a steel refinery. The spoonbill population has since grown to around 3,800—proof that it is possible to rescue species from the verge of extinction.
Binoculars to the rescue
In China several hundred birdwatchers gather for the spring migration by the Yellow Sea near the North Korean border. And Mr Wen says that local governments in China increasingly take pride in the acclaim they win for conservation schemes—several work with the WWF. A year ago China and New Zealand even signed an agreement—an “air bridge” between the two countries—to protect the habitat of the bar-tailed godwits, whose annual departure, Maori mythology holds, is for the homeland of the ancestors who first colonised New Zealand.
South Korea’s conservation movement is feeble. But the government of North Korea, by failing to develop the country, has inadvertently preserved a greater share of valuable waterbird habitats. It recently agreed to designate one as a protected site under the “Ramsar” international convention on wetlands—a rare instance of North Korea being drawn into international co-operation. Some even hope this innocuous step may prove habit-forming, paving the way for co-operation on trickier issues. After all, 30 years ago, Chinese and Russian conservationists helped thaw frosty relations between their two countries. Asia’s beleaguered waterbirds might be diplomatic as well as zoological treasures.
Exterminate first, ask questions later