December 20, 2013

Thailand is fighting an epidemic called early mortality syndrome (EMS) that could cost the shrimp industry THB50 billion (US$1.54 billion) in lost exports.

EMS is caused by orally transmitted bacteria that shut down a shrimp's digestive system, is on track to wipe out 40% of the country's annual output. It 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% in the US. Since then, prices have doubled domestically.

The president of the Thai Shrimp Association, Somsak Paneetatyasai, said that total shrimp exports for 2013 will be approximately 200,000 tonnes – valued at THB70 billion (US$2.15 billion). Last year, Thailand's shrimp haul was 350,000 tonnes, with a value of THB110 billion (US$3.39 billion).

According to Somsak despite the sharp export drop, Thailand remains the world's leading shrimp exporter this year, and the US market remains their key export market, although they'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.

Asian shrimp farmers thought the EMS epidemic would come to an end last May. 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 bacterium lives everywhere in the tropical marine environment," said Tim Flegal, a professor at Thailand's National Centre for Genetic Engineering and Biotechnology (BIOTEC), whose team is racing Lightner's in the hunt for a cure.

Flegal is also trying to determine how the bacteria spread from the ocean to a farmer's shrimp pond.

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 Aquaculture 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.