Thailand, the world’s largest supplier of shrimp, is battling an epidemic that could cost the industry 50 billion baht ($1.54 billion) in lost exports. Early Mortality Syndrome (EMS), which is caused by orally transmitted bacteria that shut down a shrimp’s digestive system, is on track to wipe out 40 percent of the country’s annual output.
EMS was first reported in China in 2009, but has since spread to Vietnam and Malaysia. The disease struck Thailand over the summer, driving the cost of shrimp up by 20 percent in the U.S. Since then, prices have doubled domestically.
The president of the Thai Shrimp Association, Somsak Paneetatyasai, told The Bangkok Post that total shrimp exports for 2013 will be approximately 200,000 tons – valued at 70 billion baht ($2.15 billion). Last year, Thailand’s shrimp haul was 350,000 tons, with a value of 110 billion baht ($3.39 billion).
“Despite the sharp export drop, Thailand remains the world’s leading shrimp exporter this year,” said Somsak. “The U.S. market remains our key export market, although we’ve now lost the number one shrimp exporter title in that market to India.”
India’s Marine Products Export Development Authority (Mpeda) announced control measures earlier this month to prevent the spread of EMS from Southeast Asia. Farmers will be required to observe a “crop holiday” from now until early February to ensure that all shrimp ponds have adequate time to dry out before being restocked.
Last May, Asian shrimp farmers thought the EMS epidemic would come to an end. Donald Lightner, a researcher at the University of Arizona, successfully identified the bacterial culprit behind the die-off. Unfortunately, Lightner was unable to pinpoint the bacterium’s source, and thus a cure remains elusive.
“That bacteria lives everywhere in the tropical marine environment,” said Tim Flegal, a professor at Thailand’s National Center for Genetic Engineering and Biotechnology (BIOTEC), whose team is racing Lightner’s in the hunt for a cure. “If we can sequence the whole bacteria genome, then we can find something unique about [it] that can be used as a marker.
Flegal is also trying to determine how the bacteria spread from the ocean to a farmer’s shrimp pond. “The most likely candidate is something that they feed to the parent shrimp – the broodstock – so they bring in live seaworms, for example from China where the disease started, and they feed them to the parent shrimp,” he added.
The Asian team has promised to make their findings public, while accusing Lightner of trying to turn a profit. They believe that he may already be sitting on a cure.
Lightner told the Global Acquaculture Alliance that EMS poses no threat to humans, even if infected shrimp are accidentally consumed. Because EMS kills young shrimp, they are often too small to enter international commerce in the first place. Regardless, some countries have restricted the import of frozen shrimp from affected regions.