China's prosperity turns seas toxic

In a generation, a lot of fertilizer and a little capitalism have revolutionized Chinas agriculture. But the gains are driving the soil and water into bankruptcy.

Nitrogen's Deadly Harvest

September 27, 2000|By Frank Langfitt and Heather Dewar | Frank Langfitt and Heather Dewar,Sun Staff


Nitrogen fertilizer has literally lifted the yoke off Hua Xijin's shoulders.

Before the "green revolution" came to China, it took roughly 6 tons of river mud to fertilize a rice paddy small enough to fit in the corner of a football field. Hua carried the mud on his back, 130 pounds at a time, in bamboo baskets lashed to a wooden pole.

Now 58-year-old Hua spends about a week each planting season sprinkling his field with hundreds of pounds of chemical fertilizer, leaving plenty of time for playing mah-jong or fishing in a nearby river.

Except there aren't any fish in the river anymore. Nor turtles, prawns or water fit to drink.

Downstream from Hua's paddy is the mighty Yangtze, the third-longest river in the world and the last stronghold of an endangered sturgeon with a 50 million-year lineage. The Yangtze is so tainted with factory waste and fertilizer runoff from more than 300 million villagers' fields that it can't even come close to meeting relatively lax Chinese standards for industrial rivers.

And where the Yangtze meets the East China Sea, toxic red tides that can kill fish and poison people now sweep through the bay that provides one-fourth of China's seafood catch.

Once rare, the potentially lethal algae now bloom two to 10 times a year. Scientists think high levels of nitrogen-laden fertilizer and animal waste from farms fuel the outbreaks -- and the amount of those contaminants flowing into the Yangtze is expected to double in less than 15 years.

The Yangtze and bountiful Hangzhou Bay just south of its mouth are headed for ecological calamity if the Chinese government fails to bring chemical fertilizer use under control, a team of scientists warned in 1997. "Urgent attention is needed," concluded the study conducted by Delft Hydraulics, an international consortium.

This is the toxic fallout from the "green revolution," which led Asian farmers since the 1960s to increasingly rely on nitrogen-based fertilizers to achieve badly needed increases in crop yields.

Meanwhile, Asian fishermen are also embracing aquaculture, the so-called "blue revolution," producing millions of tons of fish and shellfish in captivity -- along with highly concentrated streams of nitrogen from their waste.

China is the world's most dramatic illustration of man-made nitrogen's power to create and destroy. It has helped feed the world's most populous nation and eased lives of hardship unimaginable to most Westerners. But it is ruining the nation's rivers, bays and coastal waters.

And worse looms. In 20 years, experts say, Asia will be the dominant source of nitrogen pollution to Earth's air and water, producing more than all the rest of the world's nations combined and almost as much as all of Earth's natural processes.

The green and blue revolutions have already produced unintended, devastating consequences for waters all across Asia. Toxic algae outbreaks are becoming more frequent and the economic losses are mounting. In just the past year, red tides have devastated fishing grounds and fish farms in China, Thailand, Malaysia and Indonesia.

In places like South China's Zhelin Bay, fish farms are ravaged again and again. In the late 1970s, Li Zuohui saw his income skyrocket from less than $500 a year to about $25,000 because of fish farming. But today, the 47-year-old faces financial disaster each summer when red tides sweep through the bay, threatening to kill farmers' fish by the millions.

This summer, the coast south of Shanghai was blanketed with dead fish, shrimp, crabs and clams, all killed by the largest red tide ever recorded in China. At its height, the 2,700-square-mile bloom was big enough to cover Maryland's western shore from the Pennsylvania border south to Annapolis and west to the District of Columbia line.

It was among 20 to 30 red tides that Chinese experts forecast for this year. Over the past three years, the government says large red tides have done $240 million in damage to China's economy. Officials explicitly blame nitrogen pollution -- but they continue to encourage Chinese farmers to pour on the fertilizer.

Unlike Europe and North America -- where chemical fertilizer use peaked in the 1980s and declined slightly or leveled off since then -- China's use has increased fivefold in the past 30 years and will double or triple again by 2020. In parts of China, farmers already use almost four times as much nitrogen fertilizer per acre as farmers in the American Midwest.

Now that peasants like Hua can afford to eat meat regularly, big Western-style livestock operations and the animal waste they produce are becoming a major new source of nitrogen pollution.

In the past two decades, China's recorded pig sales have soared. Pig and chicken farms within the vast area of central China drained by the Yangtze produce more than 40 times as much nitrogen pollution as all the region's factories -- and that is projected to increase sharply over the next decade.

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