23 Aug 2010: Report

On China’s Beleaguered Yangtze,
A Push to Save Surviving Species

The Yangtze has been carved up by dams, used as an open sewer, and subjected to decades of overfishing. Now, Chinese scientists — alarmed by the disappearance of the Yangtze river dolphin and other creatures — are calling for a 10-year moratorium on fishing in the world’s third-longest river.

by richard stone

In the early 20th century, fishers on the Yangtze River regularly snared what may have been the biggest freshwater creature of modern times: the Chinese paddlefish. The behemoth once reached 23 feet in length, a third of that being a paddle-like snout that it used presumably to stir up the river bottom to flush out food. A single paddlefish could feed a village and was especially prized for its caviar. But decades of industrialization in China’s heartland have sounded a death knell for the king of the Yangtze. The last time one was caught was in 2003, and it hasn’t been seen since.

The paddlefish is not the only Yangtze creature to have become the stuff of legend. The last confirmed sighting of the Yangtze river dolphin, or baiji, was in September 2004. The Yangtze giant soft shell turtle, perhaps the largest freshwater turtle on Earth, is apparently extinct in the wild. The last two known individuals, a male and a female, have been united in a Suzhou
Yangtze River
Andrew Wong/Getty Images
About 40 percent of China’s 1.3 billion people live in the Yangtze River basin.
zoo but may be too old or too frail to mate. The Chinese alligator and the Chinese giant salamander are both critically endangered. The Chinese puffer fish and the Yangtze sturgeon are rarely spied these days. The Chinese sturgeon is on life support thanks only to hatcheries that release tens of thousands of fingerlings into the Yangtze each year.

Overfishing, pollution, and habitat fragmentation from dams — including the massive Three Gorges Dam — have brought the Yangtze to its current state. With more dams planned and Chinese officials intoxicated with unbridled economic growth, the future looks just as grim for the Yangtze’s vanishing species. Much of the river basin “will soon be a mere semblance of its natural state, offering few prospects for persistence of what remains of the river’s unique biodiversity,” says David Dudgeon, an aquatic ecologist at the University of Hong Kong.

All is not yet lost, however. Seasonal fishing bans have given some species a breather. “We can save the remaining ecology of the Yangtze,” argues Xie Songguang, an ecologist at the Institute of Hydrobiology in Wuhan. The potential savior that he and others are counting on is a 10-year fishing moratorium. Such a ban may seem drastic, but it would have a tiny effect on fish markets, as the Yangtze supplies less than 1 percent of China’s freshwater fish production, including aquaculture. A ban is feasible — if the political willpower can be summoned to implement it. With the Yangtze’s ecological health in obvious decline and the economic toll of a ban manageable, the prospects for a moratorium are looking better and better, experts say.

The Yangtze, the world’s third-longest river, flows 3,900 miles from its origins on the Tibetan Plateau to Shanghai, situated at the
The Yangtze has 378 fish species, including 162 that are unique, or endemic, to the river.
mouth of the Yangtze on the East China Sea. Around 40 percent of China’s 1.3 billion people live in the Yangtze basin, and the region accounts for one-third of the country’s GDP. “The Yangtze is so important for China’s economic development,” says Wang Ding, a specialist on cetaceans at the Institute of Hydrology. “That makes it very difficult to protect river life.”

Indeed, cities on the Yangtze, including Chongqing, a megalopolis of 32 million people, have long treated the river as an open sewer. More than 25 billion tons of wastewater — half of China’s total — is discharged into the Yangtze each year, says Dudgeon. Fertilizer and pesticide runoff from farm fields and contaminants from ships add to the pollution.

When Wang came to the Institute of Hydrology as a young researcher in 1982, he says, “Nobody was talking about conservation.” By the end of the decade, however, the institute realized that the baiji was imperiled and scientists began searching for ways to protect the river’s ecology. According to the latest tally, the Yangtze has 378 fish species, including 162 that are unique, or endemic, to the river.

The river may have lost its baiji, but it still has Yangtze finless porpoises, the only freshwater porpoise population. To cetaceans, a big threat is ship traffic. The 770 or so miles of the Yangtze that are navigable are a highway of cargo vessels and barges. During the baiji survey in 2006, the research vessel had to crawl up the river:

Yangtze River porpose
China Photos/Getty Images
A worker carries a Yangtze River finless porpoise, a species that Chinese officials say could be extinct within 15 years.
“There were so many ships in front of us,” Wang says. “There was no space for us, so there must be no space for animals as well.”

Like the lost baiji, finless porpoises must surface for air. They are also bothered by engine noise, which can drown out the sonar clicks the animals use to locate prey and communicate. Fish, meanwhile, fall victim to “highway maintenance”: Dredging for easier navigation destroys spawning grounds.

Another threat to wildlife is the vast engineering works that have transformed the Yangtze basin. The river is connected to a dense network of tributaries, lakes, and wetlands, some of which have been severed by dams and levees from the Yangtze to protect communities from flooding when river levels rise during the summer monsoon season. “The Yangtze is a complex ecological system,” says Wang. “Animals once could move freely through it. That’s not the case anymore.”

Hydropower projects have created even more daunting barriers. The Gezhouba Dam, completed in 1981, took a heavy toll on Yangtze fish: It blocked breeding migrations, fragmented populations, and degraded spawning sites of paddlefish and sturgeon, Dudgeon reported in the April issue of the journal Aquatic Conservation. The Three Gorges Dam, finished
The Three Gorges Dam has had a devastating effect on some fish populations.
in 2003, is an even more effective barrier to migration, he says, and has had a devastating effect on some fish populations.

“The impact has been huge. Fish resources below Three Gorges have suffered,” says Xie. The Yangtze’s four major carp species — bighead, black, grass, and silver — spawn when water levels rise during the summer rains. Three Gorges has subtly altered seasonal variations in water levels below the dam. Surveys have found a sharp decline in carp eggs and larvae downstream. “The dam has devastated spawning grounds,” says Xie.

With the ecosystem under assault, Yangtze fish are more vulnerable than ever to their main nemesis: fishers. Up until 1980 or so, Yangtze fishers used small boats and nets, so the pressure on fish was not so heavy, says Xie. Then the industry became more mechanized — trawlers got bigger, nets more sophisticated — and fish stocks were hammered. To compensate, hatcheries have been replenishing stocks of carp and other key species. And since 2000, provinces along the Yangtze have instituted a three-month fishing ban covering the spawning season. Registered fishermen receive subsidies, including rice. The government is expected to extend the ban to four months starting next year.

But that strategy may be doomed to fail. In the summer of 2007, Xie’s team found that fishers in Dongting Lake — one of two large lakes on the Yangtze floodplain connected to the river — were hauling in an estimated 6.6 million juvenile carp a day. “Compared to this huge harvest, hatchery release of commercial species is small in number and meaningless,” Xie says. The juvenile fish, too small to serve to people, are ground up and used as aquaculture feed.

Targeted fishing bans would help some species. One fish that might be saved this way is Coilia ectenes, a kind of anchovy. The fish’s range on the lower Yangtze has been shrinking, and it spawns a month later than it did a few decades ago. Overfishing reduces the distance the fish swims upriver each spring for spawning. “Loss of migration distance is not restorable,” says Xie. That means genetic diversity will decline, making the anchovy more vulnerable to extinction.

The embattled fish might be saved by its own popularity. In late March and early April, a traditional time to eat the anchovy, prices for larger fish can top $500 per kilogram ($226 per pound). In a study last year, Xie found
A moratorium may be the only hope for the Yangtze,” says one Chinese ecologist.
that large fish make up only 2 percent of the catch but more than half the income for fishers. Most big fish are caught early in the season, so the solution is simple, says Xie: Ban anchovy fishing from April 15, when all that’s left, mostly, are the fry. The agriculture ministry’s Fisheries Bureau agreed to implement the ban this year. It will take a few years to determine whether this approach will preserve what’s left of the anchovy’s truncated migratory range.

Targeted bans offer only limited hope, however. What’s needed is a long timeout. Institute of Hydrology scientists are calling for a 10-year fishing moratorium. That’s doable, says Wang. China’s freshwater fish production is approximately 30 million tons a year, of which the Yangtze catch amounts to a mere 100,000 tons.

Although “fish quality in the Yangtze is the best in the country,” he says, officials should not be deterred from ordering a long-term ban to give fish stocks a chance to recover. All 20,000 or so registered fishers could receive

MORE FROM YALE e360

Growing Shortages of Water
Threaten China’s Development

Energy Sleuths in Pursuit of the Truly Green Building
With 20 percent of the world’s population but just 7 percent of its available freshwater, China faces serious water shortages as its economy booms and urbanization increases. The government is planning massive water diversion projects, but environmentalists say conservation — especially in the wasteful agricultural sector — is the key.
READ MORE
compensation and be steered into other lines of work, the institute's scientists say. All told, around 100,000 people — the fishers and their families — depend on the Yangtze for their survival. Some fishers could be dispatched overseas as a kind of aquatic Peace Corps to advise less-developed countries on fisheries management, says former Institute of Hydrology ecologist Chen Peixun, China’s top baiji specialist.

Such a ban would have to be decreed by the Fisheries Bureau. So far, government officials are unmoved, but Wang says there is reason for optimism. “Since the situation of the Yangtze has been getting worse and worse, and the ban will have very little impact on the economy, it will be quite possible to impose a 10-year ban sometime in the next decade,” he says. A moratorium, adds Chen, “may be the only hope for the Yangtze.”

For those creatures that haven’t yet disappeared, that is.

POSTED ON 23 Aug 2010 IN Pollution & Health Water Asia 

COMMENTS


And if you think the Yangtze's bad you should see what agriculture and urban development have done to the lower Sacramento and San Joaquin Rivers here in California.

Posted by FadingFast on 23 Sep 2010


Comments have been closed on this feature.
richard stoneABOUT THE AUTHOR
Richard Stone oversees Science Magazine’s Asia news coverage. He opened Science’s Beijing bureau in October 2007 after a two-year stint in Bangkok. His writing has also appeared in Discover, Smithsonian, and National Geographic, and he is the author of Mammoth: The Resurrection of an Ice Age Giant.
MORE BY THIS AUTHOR

 
 

RELATED ARTICLES


In Mexico, Fish Poachers Push
Endangered Porpoises to Brink

China’s lucrative black market for fish parts is threatening the vaquita, the world’s most endangered marine mammal. The porpoises, who live only in the Gulf of California, are getting caught up as bycatch in illegal gill nets and killed.
READ MORE

In Japan, a David vs Goliath
Battle to Preserve Bluefin Tuna

A group of small-scale Japanese fishermen are waging an increasingly public struggle against industrial fishing fleets that are using sonar and huge nets to scoop up massive catches of spawning Pacific bluefin tuna.
READ MORE

The Sushi Project: Farming Fish
And Rice in California's Fields

Innovative projects in California are using flooded rice fields to rear threatened species of Pacific salmon, mimicking the rich floodplains where juvenile salmon once thrived. This technique also shows promise for growing forage fish, which are increasingly threatened in the wild.
READ MORE

How China and U.S. Became
Unlikely Partners on Climate

Amid tensions between the U.S. and China, one issue has emerged on which the two nations are finding common ground: climate change. Their recent commitments on controlling emissions have created momentum that could help international climate talks in Paris in December.
READ MORE

An Up-Close View of Bristol Bay’s
Astonishing Sockeye Salmon Runs

The first runner-up in the 2015 Yale Environment 360 Video Contest captures stunning images of the abundant sockeye salmon runs in Bristol Bay, Alaska, and tells the story of a 70-year-old project that has been studying the millions of salmon that annually pour into the region’s rivers to spawn.
READ MORE

 

MORE IN Reports


As Drought Grips South Africa,
A Conflict Over Water and Coal

by keith schneider
Facing one of the worst droughts in memory, South Africa’s leaders have doubled down on their support of the water-intensive coal industry. But clean energy advocates say the smartest move would be to back the country’s burgeoning wind and solar power sectors.
READ MORE

Saving Amphibians: The Quest
To Protect Threatened Species

by jim robbins
The decline of the world’s amphibians continues, with causes ranging from fungal diseases to warmer and drier climates. Now, researchers are looking at ways to intervene with triage measures that could help save the most vulnerable populations.
READ MORE

How Rising CO2 Levels May
Contribute to Die-Off of Bees

by lisa palmer
As they investigate the factors behind the decline of bee populations, scientists are now eyeing a new culprit — soaring levels of carbon dioxide, which alter plant physiology and significantly reduce protein in important sources of pollen.
READ MORE

Can Uber-Style Buses Help
Relieve India's Air Pollution?

by jason overdorf
India’s megacities have some the deadliest air and worst traffic congestion in the world. But Indian startups are now launching initiatives that link smart-phone apps and private shuttle buses and could help keep cars and other motorized vehicles off the roads.
READ MORE

Trouble in Paradise: A Blight
Threatens Key Hawaiian Tree

by richard schiffman
The ʻohiʻa is Hawaii’s iconic tree, a keystone species that maintains healthy watersheds and provides habitat for numerous endangered birds. But a virulent fungal disease, possibly related to a warmer, drier climate, is now felling the island’s cherished 'ohi'a forests.
READ MORE

Climate Change Adds Urgency
To Push to Save World’s Seeds

by virginia gewin
In the face of rising temperatures and worsening drought, the world’s repositories of agricultural seeds may hold the key to growing food under increasingly harsh conditions. But keeping these gene banks safe and viable is a complicated and expensive challenge.
READ MORE

As World Warms, How Do We
Decide When a Plant is Native?

by janet marinelli
The fate of a tree planted at poet Emily Dickinson's home raises questions about whether gardeners can — or should — play a role in helping plant species migrate in the face of rising temperatures and swiftly changing botanical zones.
READ MORE

With New Tools, A Focus
On Urban Methane Leaks

by judith lewis mernit
Until recently, little was known about the extent of methane leaking from urban gas distribution pipes and its impact on global warming. But recent advances in detecting this potent greenhouse gas are pushing U.S. states to begin addressing this long-neglected problem.
READ MORE

Is Climate Change Putting
World's Microbiomes at Risk?

by jim robbins
Researchers are only beginning to understand the complexities of the microbes in the earth’s soil and the role they play in fostering healthy ecosystems. Now, climate change is threatening to disrupt these microbes and the key functions they provide.
READ MORE

As Electric Cars Stall, A Move
To Greener Trucks and Buses

by cheryl katz
Low gasoline prices and continuing performance issues have slowed the growth of electric car sales. But that has not stymied progress in electrifying larger vehicles, including garbage trucks, city buses, and medium-sized trucks used by freight giants like FedEx.
READ MORE


e360 digest
Yale
Yale Environment 360 is
a publication of the
Yale School of Forestry
& Environmental Studies
.

SEARCH e360



Donate to Yale Environment 360
Yale Environment 360 Newsletter


CONNECT


ABOUT

About e360
Contact
Submission Guidelines
Reprints

E360 en Español

Universia partnership
Yale Environment 360 articles are now available in Spanish and Portuguese on Universia, the online educational network.
Visit the site.


DEPARTMENTS

Opinion
Reports
Analysis
Interviews
Forums
e360 Digest
Podcasts
Video Reports

TOPICS

Biodiversity
Business & Innovation
Climate
Energy
Forests
Oceans
Policy & Politics
Pollution & Health
Science & Technology
Sustainability
Urbanization
Water

REGIONS

Antarctica and the Arctic
Africa
Asia
Australia
Central & South America
Europe
Middle East
North America

e360 VIDEO

“video
Tribal people and ranchers join together to stop a project that would haul coal across their Montana land.
Watch the video.

e360 MOBILE

Mobile
The latest
from Yale
Environment 360
is now available for mobile devices at e360.yale.edu/mobile.

e360 PHOTO ESSAY

“Alaska
An aerial view of why Europe’s per capita carbon emissions are less than 50 percent of those in the U.S.
View the photos.

e360 VIDEO

“Battle
The 2015 Yale e360 Video Contest winner documents a Northeastern town's bitter battle over a wind farm.
Watch the video.

e360 VIDEO

Food waste
An e360 video series looks at the staggering amount of food wasted in the U.S. – a problem with major human and environmental costs.
Watch the video.

e360 VIDEO

Colorado wildfires
An e360 video goes onto the front lines with Colorado firefighters confronting deadly blazes fueled by a hotter, drier climate.
Watch the video.

e360 SPECIAL REPORT

“Tainted
A three-part series Tainted Harvest looks at the soil pollution crisis in China, the threat it poses to the food supply, and the complexity of any cleanup.
Read the series.

OF INTEREST



Yale