Oil from a recent spill blended with 30 years of waste dumped by cities and factories ringing the once-beautiful sea

A recent offshore oil spill has given China reason to pause for a close look at the filth floating in the Bohai Sea which, after eons of pristine beauty followed by three decades of intense pollution, is today seriously ill.

A map of polluted areas included in a 2008 Report on the Quality of the Marine Environment of the Bohai Sea, published by the State Oceanic Administration (SOA), still paints a depressing picture. It shows that the entire length of the Bohai shore, with the exception of a few sections near Hebei Province’s South Qinhuangdao and Beidaihe, as well as Liaoning Province’s Dalian, has been seriously polluted.

Moreover, the report described sea conditions long before last year’s oil tank explosion and spill in the Dalian area, and crude oil started leaking from ConnocoPhillips drilling rigs in June.

As of 2005, according to other SOA reports, about 14 percent of Bohai’s waters were polluted. The percentage had risen to 22 percent by 2010.

Tianjin, the biggest city on the sea, is both a contributor and victim of the contamination. SOA says more than 95 percent of the sea area off the city’s shore are rated Grade IV – a classification given by scientists for seawater described as “generally offensive in color, smell and taste.”

Recent efforts to clean up Bohai succeeded in reducing the total Grade IV section of the sea by half, after a peak of 6,120 square kilometers was reported in 2007. But the trend reversed in 2010, and the fouled area spread to 3,220 square kilometers.

The largest sections of polluted water in the Bohai Sea are in coastal areas that encompass fishing grounds, tourist areas and nature reserves, said Wang Shicheng, a former deputy director of the Shandong Province Ocean and Fisheries Department.

And 80 percent of the sea’s pollution comes from land sources, including factories and city sewage plants, said Xia Qing, a researcher at the China Environmental Science Research Institute and head of the organizational group that drafted a Bohai Sea Environmental Master Plan.

It’s a predicament that’s closely tied to China’s rapid, modern-day industrial development.

Scientists say the Bohai Sea has played the role of a “pollution sink” for a large swathe of modern China. About 45 rivers empty into the sea, and several major channels including the Haihe, Yellow and Liaohe rivers are major channels for manmade discharges including sewage.

Moreover, thousands of sewage outlets empty directly into the sea, including those for factories in industrial zones built in recent years in Shandong, Tianjin, Hebei and Liaoning. Many of these factories have been cited for high levels of pollution.

Overall, the amount of waste discharged into the sea greatly exceeds quotas set by environmental regulators. In 2008, for example, marine authorities who monitored 96 sewage outlets found 82 percent exceeded discharge standards. And in Shandong alone, they found 96 percent exceeded the standards.

Wang says environmental authorities have proposed forcing local companies to meet discharge standards. But questions about the standards themselves cloud this proposal. For example, separate discharge standards have been established for the steel, printing and papermaking industries.

“Environmental protection authorities think the pollution discharge situation is getting better and better,” said Wang. “But marine authorities have found it to be getting worse and worse.”

One proof of deteriorating conditions is the shrinkage of the heavily tapped Yellow River before it reaches the sea. The Yellow is the sea’s most important river, but so little water winds up reaching the sea that salinity levels in the Bohai have risen to the point of seriously inhibiting fish spawning.

Another harmful consequence of sea pollution is eutrophication, which can lead to red tides. One such “micro-micro-flagellate” red tide algae bloom lasted from late May to early July in Hebei’s Changli County.

This was the third consecutive year in which the county’s seacoast experienced red tides, which halt development of young scallops and kill others.

By staff reporter Gong Jing