By Jason Gale, Lydia Mulvany, and Monte Reel, Bloomberg Businessweek
From the air, the Pearl River Delta in southern China’s Guangdong province resembles a mass of human cells under a microscope. Hundreds of thousands of tiny rectangular blocks, all of them shades of green, are clustered between cities and waterways. Livestock pens are scattered among the thousands of seafood farms that form the heart of the country’s aquaculture industry, the largest in the world.
“People eating their shrimp cocktails and paella may be getting more than they bargained for,” says Dr. Martin Blaser, a professor of microbiology and an infectious diseases physician at New York University Langone Medical Center who chairs President Barack Obama’s advisory panel for combating antibiotic-resistant bacteria. “The penetration of antibiotics through the food chain is a big problem.”
Research has found that as much as 90 percent of the antibiotics administered to pigs pass undegraded through their urine and feces. This has a direct impact on farmed seafood. The waste from the pigpens at the Jiangmen farm flowing into the ponds, for example, exposes the fish to almost the same doses of medicine the livestock get—and that’s in addition to the antibiotics added to the water to prevent and treat aquatic disease outbreaks. The fish pond drains into a canal connected to the West River, which eventually empties into the Pearl River estuary, on which sit Guangzhou, Shenzhen, Hong Kong, and Macau. The estuary receives 193 metric tons (213 tons) of antibiotics a year, Chinese scientists estimated in 2013.