From: BRosenberr@aol.com
To: AQUA-L@listserv.ifmt.nf.ca
STATUS OF SHRIMP FARMING IN THAILAND
I'm Bob Rosenberry, editor and publisher at Shrimp News International. From December 7 to December 14, 1996, I participated in a U.S. Media Tour of Thailand's shrimp farming industry. Four other journalists also participated in the tour, which was organized by
Thailand's Department of Export Promotion and implemented by the Thai Department of Fisheries. The Thais rolled out the red carpet for us: police escorts through busy traffic, the best hotels, the finest restaurants, lots of shrimp, never an empty glass.
We met with high government officials and exporters, then visited research facilities, laboratories, a processing plant, a pumping station, a mangrove restoration project, a turtle restoration project--and shrimp farms in eastern and southern Thailand.
As you probably know, shrimp farming nations around the world are under attack from environmental groups that say shrimp farming destroys mangrove forests. In the early 1980s, when the Thai industry practiced extensive and semi-intensive farming, the mangroves were developed for shrimp farming. Since 1987, however, the intensive management techniques required for disease control have forced most farms out of the mangroves and on to higher ground. I'll provide more details on the mangrove issue in subsequent
articles.
Here I want to bring you up-to-date on the shrimp farming situation in
Thailand and tell you a little about the people who participated in the tour.
The Current Situation
Thailand leads the world in shrimp farming. For the past 5 years, it has been the world's biggest producer of farmed shrimp, and, in 1996, it accounted for more than 25% of the farmed shrimp placed on world markets. Most importantly, it has a government and university system that really supports the industry and encourages environmentally responsible shrimp farming.
The Department of Fisheries and the aquaculture division of the Charoen Pokphand Group (CP, a huge corporation with interests in shrimp feeds, farming and exports) estimate that Thailand produced 200,000 metric tons of farmed shrimp in 1996. That's 25% higher than my estimate of 160,000 tons, which appeared in World Shrimp Farming 1996.
Thailand now has 26,000 shrimp farms! That's 62% more than my estimate of 16,000 in World Shrimp Farming 1996.
Farms--85% of them intensive--utilize 80,000 hectares of ponds, mostly on the high ground inland from the mangroves. Most of the farms are in southern Thailand (55%), but there are also farms in central (10%) and eastern (35%) Thailand. Approximately 80% of the farms are smaller than 1.5 hectares, another 18% are between 1.5 and 2.5 hectares, less than 2% are larger than 10 hectares.
With five feedings per day, feed conversion ratios range from 1.5 to 2.0. Harvests reach 10,000 to 12,000 kilograms per hectare per year. To stay profitable, farmers produce large shrimp (around 30 to 40 whole animals per kilogram, or 15 to 20 animals per pound).
Yellowhead: This viral disease attacks juveniles and sub-adults. It's still a big problem in Thailand. It kills quickly and then disappears, maybe forever, maybe not.
Whitespot: Once established, this viral disease, which attacks shrimp shortly after stocking, seems to be ever-present, never going away. Although private sector farmers around Suratthani say whitespot is still causing production shortfalls, Thailand's shrimp farmers have made tremendous strides in overcoming whitespot and yellowhead. Management strategies that work with whitespot also work with yellowhead.
How did Thailand overcome the whitespot virus so quickly? The Department of Fisheries instituted a policy of screening broodstock (captured offshore) for viruses and then set up a network of laboratories to do the actual screening. The labs reported a low incidence of whitespot in the wild broodstock.
Next, farmers chlorinated their ponds to kill off carrier species. Then,
before stocking, the postlarvae were checked for viruses (PCR technique, expensive). Farmers stocked 25 to 30 postlarvae per square meter, reduced from 60 per square meter in previous years. Surprisingly, the lower stocking densities did not reduce production! Better water, healthier seedstock, less "over stocking" stress, and improved management all contributed to higher survivals. The private sector helped spread the word about these new management techniques at regional disease prevention seminars.
Farming Strategies: Some farms don't exchange any water, practicing what westerners call "zero-exchange" and the Thais call "closed system" farming. Other farms use recirculating systems, where the water flows from a big reservoir, which might be 15 to 20% of the total farm area, to ponds and back again, over and over. These systems might include polyculture with fish or mollusks, and technology for removing sediment and sludge from the system. A group of shrimp farmers in eastern Thailand employs a system of mangroves, mollusks and fish to purify its effluent. Government officials say approximately 50% of the industry uses the new management systems.
Shrimp don't grow as quickly in these systems as they do in flow-through systems, so in areas where viruses are not a problem, farmers practice flow-through farming. Some of these farms locate in the mangroves.
Although you can grow shrimp year-round in Thailand, many farmers strive for two crops a year, one from March to July and another from July to November, avoiding the coldest months of the year when cooler waters stress shrimp and encourage viruses.
Aeration: Throughout Thailand, long-arm paddlewheel aerators appear to be replacing independent, self-powered aerators (electro/mechanical devices which add oxygen to the water). The power for long-arm aerators sits on the bank and is transferred to a long row of floating paddles via a spinning pipe. Although they don't spin as fast as independent paddlewheels, the long-arm aerators create a circular flow that concentrates waste products in the center of the pond. After a drain harvest, the pond bottom is dried.
Then the sludge is bulldozed to the side of the pond, collected and used for landfill in low lying areas.
Brine Shrimp: Although we didn't visit any hatcheries on the tour, I talked with some hatchery guys about the price of brine shrimp eggs. When hatched, brine shrimp eggs (almost all of which are harvested from Utah's Great Salt Lake, USA), produce a little critter that has the perfect nutritional profile for feeding the larval stages of farmed shrimp. The same critter, as it grows larger, becomes a good feed for juvenile shrimp and shrimp broodstock. During 1995-96, when the price of brine shrimp eggs went up by 400%, Thai hatcheries cut their orders by 50%. They supplemented hatchery diets with dry feeds and let the critters grow larger before feeding. Lower stocking
densities on farms and lower pond mortalities reduced the need for seedstock, further reducing the need for brine shrimp eggs. These developments go a long way toward explaining the rapid decline in brine shrimp egg prices which began during the spring of 1996. It appears that Thailand has weathered the worst of the whitespot crisis, and that its shrimp farming industry is on the rebound. Hopefully, this will result in a stable, expanding market for brine shrimp eggs.
Shrimp farming and the environment will be a hot topic at the upcoming World Aquaculture Society Meeting in Seattle (February 19-24, 1997). Thai scientists will make several presentations at the meeting. Information: John Cooksey, Conference Manager, World Aquaculture Society, 21710 7th Place West, Bothell, WA 98021 USA (phone 206-485-6682, fax 206-483-6319, e-mail worldaqua.aol@com).
For the full version of this report (including list + background of participants and contact persons in Thailand, contact:
Bob Rosenberry, Editor/Publisher
Shrimp News International
9450 Mira Mesa Boulevard, Suite B-562
San Diego, CA 92126 USA
Phone 619-271-6354
Fax 619-271-0324
E-Mail Shrimpnews@aol.com
Web Page http://members.aol.com/brosenberr/Home.html
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