A Better Shrimp

Shrimp Farm, Sam Roi Yot National Park

Bunjonk Nissapawanich’s shrimp farm appears no different from the tens of thousands of similar operations found in and adjacent to Thailand’s aquatic areas. But were one to take note of the constant stream of researchers who regularly visit his 18-hectare facility, it’s clear that something significant is under way here.

Indeed, nothing less than the maintenance of Thailand’s worldwide leadership in shrimp exports, valued at $2.64 billion in 2009, is tied up in Bunjonk’s rows of concrete tanks and earthen ponds located 100 km east of Bangkok. Specifically, efforts are under way to produce black tiger shrimp (Penaeus monodon) that are faster growing, more disease resistant and of more uniform size than anywhere else in the world.

“Our dream is to have other countries depend on us when they look for good disease-free black tiger shrimp,” says Morakot Tanticharoen, vice president of the National Science and Technology Development Agency (NSTDA).

The NSTDA Shrimp Research Program provides Bunjonk’s domesticated stock that originates from the Gulf of Thailand and the Andaman Sea. The shrimp that reach him have gone through extensive selection and breeding to ensure SPF (specific pathogen-free) stock and growth quality.

First, workers quarantine the candidate breeding stock at a research facility in Nakhon Si Thammarat province, where they are screened and reared to produce SPF shrimp. The Nucleus Breeding Center, another laboratory in Surat Thani province, evaluates the genetic traits of the SPF stocks. Currently, there are 30 distinct SPF breeding stock (broodstock) families, and BIOTEC (the life science research arm of NSTDA) plans to expand the collection to 200. Cross-breeding is aided by genetic analysis and DNA markers. SPF broodstock prototypes are then sent to another facility in Chanthaburi province, where they reproduce, before arriving at Bunjonk’s in Chacheongsao and a companion’s farm in Surat Thani province in the South, and Chantaburi and Chachoengsao provinces in the East, for rearing and circulation to commercial farmers.

Since 2007, these two hatchery farms have helped distribute more than 3,000 broodstock and 30 million postlarvae. “So far the feedback from the local farmers is not great, as the shrimp are smaller than wild species,” said Bunjonk. But Morakot is pleased that the shrimp remain healthy and is confident that further efforts will yield a desirable size.

Also known as giant or jumbo tiger shrimp, black tiger shrimp are the largest in the world, growing up to 36 cm long, and weighing up to 650 grams. They were once the mainstay for Thai shrimp farmers until disease and declines in natural broodstock brought production to a standstill in 2002.

This forced farmers to switch to Pacific White shrimp (Penaeus vannamei) and to use broodstock imported from Hawaii. Smaller and less expensive to raise, Pacific White shrimp now represents 98 percent of shrimp farmed and exported from Thailand.

However, fierce competition among shrimp exporters from other countries has caused BIOTEC to emphasize research on the pricier black tiger shrimp as a strategy for Thailand to stay one step ahead. While Thailand’s yield per hectare in both Pacific White and black tiger shrimp remains one of the highest in the world, the sector is facing increased competition from Vietnam, China, India, and Indonesia.

“In the long run, Thailand will be unable to sell shrimp as a commodity because competitors will have lower labor costs. We have to sell a premium product to a high-end, niche market,” says Morakot.

Pacific White shrimp currently commands $6–$7 per kilogram, while black tiger shrimp can fetch upwards of two to three times this price.

The Thai government also hopes that BIOTEC’s shrimp program will strengthen the country’s food safety image, something that is becoming increasingly important to importers. BIOTEC’s broodstock will have an advantage should countries place bans on wild shrimp due to environmental or disease concerns, since it’s much easier to test domesticated farmed shrimp broodstock for food safety.

“In the future we hope farmers can open a catalogue that highlights our black tiger shrimp broodstock and order shrimp that represent the quality, size, and weight they want,” adds Morakot.

Biotechnology has been at work in Thailand’s shrimp industry since the 1980s. Notably, the outbreak of yellow-head virus (YHV) in the early 1990s dramatically reduced production nationwide, and prompted scientists to ramp up research programs to better understand the species. In 1996, Chulalongkorn University started the genetic work on shrimp, with the study of DNA of black tiger shrimp in the Gulf of Thailand and Andaman Sea, along with their migration patterns and mating behavior.

The same year, biologists at Mahidol University produced the first diagnostic kit to test for YHV by employing PCR to magnify the viral DNA up to one billion times. Last year, a less expensive and simpler diagnostic kit emerged that uses loop-mediated DNA amplification (LAMP) and gel strips.

BIOTEC researchers at the Center of Excellence for Marine Biotechnology, a BIOTEC satellite lab at Chulalongkorn University, have recently begun extracting and commercializing hormones from sea worms (Polychaetes) as a dietary supplement to enhance gonad development in both male and female shrimp, resulting in more rapid fertilization and spawning frequency.

In 2007, BIOTEC researchers at the Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp), based at Mahidol University, isolated the protein PmRab7 in shrimp that can block the White Spot Syndrome Virus’s entry into shrimp cells, dropping mortality rates from 100 percent down to 15 percent.

Combined, Thai researchers have secured 15 patents on shrimp technology on such things as diet, diagnostic kits, and wastewater treatment systems that can treat nitrogen and facilitate water recycling. Only the United States, European Union, and Japan have more patents related to shrimp aquaculture.

But not everyone views such developments as positive. Too much emphasis is being placed on black tiger shrimp, says Sathit Panich, an independent supplier to shrimp farmers. “In future, shrimp will become an increasingly important protein source worldwide and Pacific White Shrimp can fill that need more easily, at less cost, and utilizing less land,” asserts Sathit. He wants to see the government develop products and technologies for Pacific White shrimp farmers as well.

Morakot acknowledges Sathit’s concern, noting that the government is not avoiding efforts that might improve the competitiveness of Pacific White shrimp farmers. Indeed, most of BIOTEC shrimp technologies such as diagnosis kits and wastewater treatment can and are being used for Pacific White shrimp farms. “It’s just that in the long run, we feel the industry as a whole will benefit most by leading the world in black tiger shrimp production,” she asserts.