Shanghai's Tide of Dead Pigs

Large numbers of dead pigs have been seen floating in Shanghai's Huangpu River since March 5. As of the afternoon of March 11, over 3,000 dead pigs had been collected from the river, raising concerns about the safety of drinking water among Shanghai residents. Workers promise to work from morning to night to clean the carcasses out of the river, and the water bureau is testing the water for E coli and other pathogens every four hours.

Dead pigs in Shanghai River

Dead pigs in waterways are not an uncommon occurrence in China. In 2010, a similar incident occurred in Hangzhou but less than 600 pigs were pulled out of the river.

One Shanghai resident reported on a microblog, “This kind of thing has happened for many years; walking along the shore at low tide you can see many more dead pigs."

Dead pigs in rivers are usually an indicator of a disease epidemic. Evidence of porcine circovirus type II was detected by the Shanghai animal disease prevention and control center in tests of samples from various internal organs of dead pigs. Tests for other diseases--foot and mouth disease, classical swine fever, highly-pathogenic "blue ear" disease, pseudorabies and porcine diarrhea--were all negative.

According to the Pig Site, Circovirus is present in a large percentage of pig herds worldwide. It often has no clinical symptoms until mixed with some other infection. It is not well understood how circovirus causes disease. Effects are diverse, ranging from pneumonia to a pig-wasting syndrome, an unusual skin disease. It affects mainly young pigs, but also can affect adults and sows. Representatives from unidentified Shanghai government departments held a "press conference" where someone recited the information about circovirus identical to what's on the Pig Site. They offered no details on evidence of symptoms in the carcasses. They did warn that the disease can spread when pigs are not cared for adequately, are kept in crowded conditions and when pigs from different origins and of different ages are kept together.

Where did the pigs come from? Authorities say they are investigating and provide a sketchy finding that they came from upstream in Jiaxing and Pingdu of Zhejiang Province, and parts of Jiangsu. A professor at Fudan University's Regional Pollution Control Institute expressed dismay that authorities have not yet discovered the source of such a large number of pigs several days after it occurred. He said pigs are required to have ear tags that record information about them. Such a large number must have come from an identifiable source.

Ear tag (small round thing) in dead pig.

The local newspaper in Jiaxing, one of the sources of the dead pigs, reported sightings of dead pigs in five counties on March 4. A reporter said he saw 40-to-50 pigs from a bridge in Pingdu City. Villages reportedly have stations to dispose of dead pigs but many farmers put the carcasses in bags and throw them in the weeds on creek banks. The reporter found a number of dead pigs in the weeds along a creek near the Shanghai-Hangzhou expressway, some in fertilizer bags, some lying on the ground.

One farmer said that he can usually call someone to collect dead pigs for disposal, but sometimes they are busy and no one comes. Then, he just throws them away somewhere. The farmer said traders used to come to buy the dead pigs, but they stopped coming after authorities cracked down on the sale of meat from dead pigs last year.

Another Jiaxing Daily article reported on a visit to Bamboo village, where 1400 farmers raise pigs and get 85 percent of their income from hogs. The official in charge of pollution control in the village showed the reporter records showing that over 10,000 pigs had died in January, over 8,300 in February and 800 a day in early March. He said they had been digging one pit after another to dispose of the carcasses but there wasn't enough room to bury them.

According to this worker the high density of pigs is the root of the dead pig problem. The village has 8000 mu (about 1300 acres) of land that could support 1600 pigs according to usual standards of land-per-pig. He says the village's land could support two pig farms but they had surpassed the standards long ago.

Villagers are aware of the pollution problems. They collect 10 yuan per hog from villagers to fund pollution control. The village spends 1 or 2 million yuan per year but the environment is still not good. Some villagers worry about what the environment will be like in the future.

When asked about limiting the number of hogs to address the problem, village officials say that's impossible. In addition to the farmers who rely on pigs for income there are brokers, feed and veterinary drug dealers, truck drivers...what would they do?

Actually, local authorities had banned pig-raising in this area last year. During the last two years local authorities banned pig-raising in designated districts adjacent to the South Lake in order to address the pollution problem. Bamboo village was in the pig-ban area but it's not clear what will happen. Pig-raising is still going strong, at least until the dead pig phenomenon appeared. The Jiaxing Daily said they would be watching this situation and invited citizens to contact them with suggestions. The paper also recommended setting up dead pig surveillance committees made up of either retired village officials or schoolchildren who have received good moral education. It said pollution is a problem of public morality that can't just be left to the government to solve.