Free News March 31, 2006

At "Aquaculture America 2006", the recent World Aquaculture Society Meeting in Las Vegas, Dr. Kenneth Hasson, a scientist with the Texas Veterinary Medical Diagnostic Laboratory, said: "Imported White Spot Syndrome Viruse-infected frozen shrimp are being sold as bait in Texas and probably throughout the United States for both fresh and saltwater fishing. We feel that risk analysis studies are needed, and long overdue, in order to determine if these imported frozen shrimp product pose a threat to farmed and wild shrimp in the United States."

Hasson went on to say: "With this objective in mind, about four months ago, a small group of us in Texas, together with industry input, drafted a petition addressed to USDA/APHIS [United States Department of Agriculture/Animal and Plant Health Inspection Service] requesting that this agency conduct a risk analysis of imported bait shrimp. I'm happy to report that we obtained very good support for the final petition with over a hundred signatures and eleven letters of endorsement from various agencies and institutions, including the Texas Aquaculture Association, Texas Parks and Wildlife, the United States Marine Shrimp Farming Program, the National Aquaculture Association and the United States Chapter of the World Aquaculture Society."

"We presented the petition to representatives of USDA/APHIS yesterday [February 15, 2006]."

Excerpts from Petition Letter

A letter of request (January 11, 2006) to USDA/APHIS from the Concerned Residents of Texas said:

The Gulf of Mexico shrimp fishery and Texas shrimp mariculture produce 30% of the 200 million pounds of shrimp annually harvested in the USA. Considering the highly infectious nature of some shrimp viruses, we are concerned that these resources could potentially be impacted through the unrestricted importation and commercial sale of fresh-frozen "green" bait shrimp for the purpose of sport fishing.

Frozen bait shrimp have been reported as a source of OIE-notifiable (Office Internationale des Épizooties, Paris, France) penaeid shrimp viral pathogens with no subsequent risk assessment studies conducted to determine the actual disease introduction potential of this product to USA waters.

The annual quantity, origin, distribution and health status of imported bait shrimp sold in the USA are unknown. The recent detection of viable WSSV in commercially available imported bait shrimp by the Texas Veterinary Medical Diagnostic Lab has raised further concerns about this product and motivated the submission this petition requesting that risk assessment studies be initiated by USDA/APHIS to determine if imported bait shrimp pose a disease threat to farmed and indigenous crustaceans in the USA.

Although these viral pathogens have cost the global shrimp farming industry billions of dollars in lost revenue, their potential impact on wild crustacean stocks is presently unknown.

The following is a brief summary of disease screening results obtained from investigative studies on imported frozen shrimp products:

1. Studies conducted by the University of Arizona since 1995 have demonstrated the presence of the three principal OIE-notifiable penaeid shrimp viruses (White Spot, Yellowhead and Taura) in imported frozen shrimp destined for human consumption.

2. A researcher at the Waddell Mariculture Center demonstrated the presence of infectious Taura virus in imported frozen shrimp of indeterminate origin that were being sold as bait in South Carolina.

3. In a recent small disease survey conducted by Texas Veterinary Medical Diagnostic Laboratory during 2005 (Hasson et al., in press), infectious WSSV was found in imported frozen bait shrimp originating from China. This product consisted of two species of wild shrimp indigenous to Asia that are currently being sold in Texas (and possibly throughout the USA) for use in both fresh and saltwater fishing.

We believe that the continued introduction of imported, fresh-frozen, infected bait shrimp into USA coastal environments poses a potential health risk to coastal shrimp farms. It is unknown whether continued introductions of infected bait shrimp pose additional risks to indigenous crustacean populations (e.g. commercial shrimp and crabs) or whether these populations have been affected previously. Another important concern is the possible introduction of other penaeid shrimp diseases, either currently known or yet to emerge, into USA waters by this route.

In 1996, Australia initiated risk assessment studies on imported bait shrimp. During the studies, a ban was imposed on the import of frozen bait shrimp, and that ban remains in place today. Many countries have adopted OlE recommendations regarding the testing of live shrimp imports, but considerable variation is seen in policies regarding the import of frozen shrimp products.

Brazil has banned all frozen shrimp imports since 1999 to prevent the introduction of shrimp diseases. Similarly, Mexico, Colombia and Nicaragua have implemented mandatory PCR screening of frozen shrimp imports as a precautionary measure to prevent the introduction of shrimp diseases.

We view the proposed risk assessment studies as an important first step to safeguarding both our domestic shrimp industry and wild crustacean populations.

From the Abstract of Hasson et al Paper

Evidence linking imported frozen shrimp to the direct introduction of shrimp viral pathogens into USA waters is limited to a single disease survey of TSV-infected imported bait shrimp. In this survey, twenty boxes of frozen, wild-caught bait shrimp from China (Parapenaeopsis sp. and Metapenaeopsis sp.) and eight boxes of frozen, wild-caught bait shrimp harvested from the Gulf of Mexico (Litopenaeus setiferus and Farfantepenaeus duorarum) were purchased in Texas and evaluated for the presence of five OIE-notifiable shrimp viral pathogens (TSV, WSSV, YHV/GAV and IHHNV).

All 28 boxes tested negative for the presence of TSV, YHV/GAV and IHHNV by PCR. No WSSV was detected in the eight native bait shrimp samples, but two boxes of imported shrimp (Parapenaeopsis sp.) from China tested WSSV-positive by nested and single-step PCR procedures. To determine the viability of these WSSV PCR-positive samples, replicate treatment groups of SPF-derived Litopenaeus vannamei juveniles (3-4 grams average weight) were injected intramuscularly with 0.2 µm filtered tissue homogenates prepared from each of the two WSSV-positive boxes. All virus-exposed shrimp died within 48-72 hours in two separate bioassays. No mortalities occurred among the negative control groups that were maintained ten days post-exposure to noninfected tissue filtrates. Histological analysis revealed severe WSSV infections in all ten moribund shrimp examined from each bioassay.

WSSV infection was not induced in a 21-day per os study in which bioassay shrimp were exposed to minced tissues prepared from the two WSSV-positive bait samples. This negative result was attributed to virus inactivation resulting from repeated freeze-thaw cycles of the infected bait samples during the initial PCR testing phase. To prevent virus inactivation during sampling, a new method for collecting tissue from frozen blocks of shrimp (without thawing) was developed and will be discussed.

We believe that risk analysis studies of imported frozen bait shrimp are needed to determine if this product poses a disease threat to both the USA shrimp industry and wild indigenous crustaceans.

Information: Ken Hasson, Ph.D., and Patricia Varner, Ph.D., DVM, Texas Veterinary Medical Diagnostic Laboratory, Drawer 3040, College Station Texas 77841-3040 USA (phone 979-845-3414, fax 979-845-1794, email khasson@tvmdl.tamu.edu and pvarner@tvmdl.tamu.edu).

Aquaculture America 2006 Information: John Cooksey, World Aquaculture Conference Management, 2423 Fallbrook Place, Escondido, CA 92027 USA (phone 760-432-4270, fax 760-432-4275, email worldaqua@aol.com, webpage www.was.org).

Sources: 1. Recording of Ken Hasson's presentation at Aquaculture America 2006. February 16, 2006. 2. Letter to Dr. Peter Merrill and Dr. Jill Rolland, USDA/APHIS from the Concerned Residents of Texas. Subject: Risk assessment of imported frozen bait shrimp by USDA/APHIS. January 11, 2006. 3. The CD of the Aquaculture America 2006 Abstracts. White Spot Syndrome Virus (WSSV) Introduction into the Gulf of Mexico and Texas Freshwater Systems through Imported Frozen Bait Shrimp. Ken W. Hasson, Yaping Fan, Jon A. Venuti, Tony Reisinger and Patricia W. Varner (Texas Veterinary Medical Diagnostic Lab, 1 Sippel Road, College Station, TX 77843 USA).

Australia
Cyclone Hits Queensland Shrimp Farms

Flooding from Cyclone Larry has devastated shrimp farms in Queensland, which supplies 40 percent of Australia's shrimp. Scott Walter from the Australian Prawn Farmers Association says there have been huge losses due to floods and loss of power. Walter said: "We need power to run the aerators in our ponds, which keep the oxygen levels up to a point where the prawns are capable of basically growing and surviving. So if we lose the ability to oxygenate our ponds we'll lose our crops, and if the freezers go down for too long and the seals are broken, the temperatures will rise and we'll have to destroy the stock because it'll no longer be safe for food."

Source: ABC Rural (Australian Broadcasting Corporation). N Qld cyclone damage hits prawns, avocado producers (http://www.abc.net.au/rural/news/content/2006/s1598054.htm). March 22, 2006.

Australia
Coral Sea Farm Wins Contest, Offers Jobs

Coral Sea Farm, a shrimp farm in northern Queensland (near Ingham), entered its black tiger prawns in the Sydney Royal Fine Food Show and walked away with three of the five gold medals in its category.

Coral Sea Farms is expanding its farming operation and has positions open for:

Husbandry Manager: We are seeking an experienced hands-on individual to oversee all aspects of growout. A minimum of five years farming Penaeus monodon is required. We are aware of the responsibilities involved in this position and offer attractive opportunities for the right candidate.

Line Manager/Senior Pond Technician: Experienced pond technicians with strong leadership skills and the ability to make informed decisions are sought for this senior role. The successful candidate will be responsible for coordination of the day-to-day operational aspects of pond management. Reporting to the Husbandry Manager he/she will in turn direct the activities of a team of technicians. Diploma/degree in aquaculture or equivalent required.

Information: Coral Sea Farms, P.O. Box 84, Macknade, QLD 4850 Australia (email naude@coralseafarms.com.au, fax 07-4777-2793).

Source: FisheNews (an email supplement to Austasia Aquaculture magazine, www.austasiaaquaculture.com.au). Editor, Tim Walker (austasiaaquaculture@netspace.net.au). Prawns: Black Tigers Win at Sydney Royal Fine Food Show. Employment: Senior Positions, Prawn Farm. March 23, 2006.

Brunei (a small nation on the north coast of Borneo)
"Rostries"

According to Senior Fisheries Officer Awg Sabri, shrimp farming was introduced to Brunei in early 1994. At present, he said, there are 13 farms with a total area of 230 hectares farming Tiger shrimp and "Rostries" [Penaeus stylirostris, remnants of a Super Shrimp project]. In 2005, production was 394 metric tons, sold in local markets and exported to the USA, Taiwan, Japan, Malaysia and Singapore.

The Fisheries Department has opened a new, 459-hectare area in Tutong to shrimp farming. The offer is open to local entrepreneurs and foreign investors. Proposals must be submitted to the department by April 25, 2006.

Source: BruneiDirect.com (online news Brunei). Vast Potential in Aquaculture To Be Tapped (http://www.brudirect.com/DailyInfo/News/Archive/Mar06/230306/nite22.htm). Achong Tanjong. March 23, 2006.

Namibia (Southwest Africa)
Alec Forbes

Dr. Alec Forbes, says, "Shrimp production is gaining momentum around the world. We have some very big players who are looking at Namibia to invest."

Since 2004, Dr. Forbes has been working for Namibia's Ministry of Fisheries and Marine Resources under the Commonwealth Fund for Technical Cooperation (CFTC). The fund assists member countries with development projects at the request of their governments. The CFTC project with Dr. Forbes was set to be completed in 2006, but it now has been extended until 2008.

Dr. Forbes and his team want to increase Namibia's shrimp production. The country is too cold for tropical techniques, so Forbes is looking at greenhouse culture as a way to extend the growing season.

Information: Dr. Alec Forbes, Special Aquaculture Adviser, Ministry of Fisheries & Marine Resources, Commonwealth Secretariat, Private Mail Bag 13355, Windhoek, Namibia (office phone 264-61-205-3110, direct line 24 hours 264-811-278-570, fax 254-233-286, email aforbes@mfmr.gov.na and docalec@hotmail.com).

Sources: 1. Namibian.com (online news Namibia). Health and wealth benefits for Namibia (http://www.namibian.com.na/2006/March/national/06FBD01C4.html). Robyn Bresnahan. March 15, 2006. 2. Email to Shrimp News International from Robyn Bresnahan (r.bresnahan@commonwealth.int) on March 22, 2006.

Thailand
Alltech's "NuPro" Replaces Fishmeal

Alltech Inc., a global feed biotechnology company, markets a product called "NuPro", designed to replace the fishmeal in aquaculture feeds. Developed by Drs. Ewen McLean and Steven Craig, researchers at the Virginia Tech Aquaculture Center (Virginia, USA), it's yeast-based and organically certifiable.

From June to October 2005, NuPro was tested at the Organic Aquaculture Institute (below, a nonprofit organization that conducts research on organic fish and shrimp farming) with Penaeus vannamei maintained under organically certified protocols.

A microbial food chain was encouraged in the ponds. Ponds did not receive prepared feed during the first 30 days of the trial; they were fertilized with composted manure applied at a rate of 51 kg/ha every two weeks, a protocol that was continued throughout the trial. On July 16, 2005, ponds began receiving commercial feeds. Initially, feed was applied at 18 kg/day as two equal feedings, then on October 1, it was lowered to one feeding of 14 kg/day.

Ponds receiving the NuPro-based feed had equivalent growth to those fed the traditional, fishmeal-based diet. Percentage increase in weight from initial values and survival for the NuPro ponds was 296, 269 and 275% and 78, 76 and 85%, respectively. Percentage increase in weight from initial values and survival for the control pond were 305% and 80%.

Feed conversion ratios averaged 0.52 for the NuPro fed ponds compared to 0.51 for the shrimp fed the commercial fishmeal-based feed. Overall production for the trial was approximately 10,900 kg of harvested shrimp with a feed input of 5,450 kg.

Information: Daniel Fegan, Alltech Biotechnology Corp., Ltd., 5th Floor, Preecha Building, 2533 Sukhumvit Road, Bangchack, Prakhanong, Bangkok 1260 Thailand (phone 66-2742-4545, fax 66-2742-4547, email dfegan@alltech.com).

Information: Bart Reid, Organic Aquaculture Institute, P.O. Box 448, Imperial, TX 79743 USA (phone 915-356-2216, fax 915-536-2216, email pssc@west-tex.net).

Source: Fish Farming International (http://www.fishfarming.co.uk). Editor, Kenny McCaffrey (kenny.mccaffrey@informa.com). Shrimp without the fish! Volume 33, Number 3, Page 8, March 2006.

Thailand
Tim Flegel-SPF Not Sufficient

In the February/March 2006 issue of the Global Aquaculture Advocate, Dr. Timothy Flegel, a professor at Thailand's Mahidol University, concludes a two-part discussion on the dangers of translocating shrimp with the following recommendations:

Given the propensity of shrimp, crustaceans and other arthropods to carry viral infections, it is reasonable to suggest that the International Council for the Exploration of the Seas (ICES) guidelines be modified and closely followed to guard against the possibility of introducing new viral pathogens. It is not sufficient to certify the exotic animals as "pathogen-free" from a list of known pathogens with available diagnostic tests. There is additional danger from previously unknown viruses or variants of known viruses for which no assay methods exist.

Given the experience with IHHNV in Penaeus monodon, it would seem prudent to add to the ICES guidelines a special requirement that native species of shrimp and other economically important crustaceans be included as cohabitants in the quarantine phase of the importation process. This would guard against the unintentional transfer of well-tolerated, unknown pathogens from the exotic hosts to the local species.

As shrimp aquaculture expanded globally, exotic species of shrimp were shipped legally and sometimes illegally around the world. The unseen diseases some of the shrimp carried were consequently spread to new areas and species. More complete and consistent inspection, quarantine and diagnostic measures could help alleviate the problem of diseases spread by animal shipments.

Source: The Global Aquaculture Advocate (http://www.gaalliance.org). Editor, Darryl Jory (dejry2525@aol.com). Health Management: Dangers of Viral Pathogens in Translocated Shrimp Part 2. Timothy W. Flegel, Ph.D. (Centex Shrimp and BIOTEC, Chalermprakiat Building, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400 Thailand, email sctwf@mahidol.ac.th). Volume 9, Issue 1, Page 70, February/March 2006.

Thailand
Weather Stops Shrimp Farmers

Pokklong Kerdsuk, chairman of the Krabi Shrimp Farming Club, says that rain, heat and humidity during this year's dry season have forced about 50% of the shrimp farmers to shut down along the Andaman Sea, where about 300 hectares of ponds are spread over five districts.

Source: ThaiNews.com (online news, mostly in Thai). Andaman News: Humidity and heat damage the prawn farming in Krabi forcing some to halt their operations (http://www.thaisnews.com/news_detail.php?newsid=166464). March 21, 2006.

Thailand
Zeolite

The purpose of this study was to evaluate the characteristics of 25 different zeolite products purchased from shrimp supply stores in Thailand in June 2003.

None of the products appeared to be of much value for ammonia removal. Therefore, there is no reason to recommend one product over the other. The best recommendation is to refrain from using zeolite for ammonia removal from pond waters.

Source: Journal of the World Aquaculture Society. Evaluation of Zeolite Products Used for Aquaculture in Thailand. Orawan Silapajarn (Department of Fisheries and Allied Aquacultures, Auburn University, Alabama 36849 USA), Kom Silapajarn (Thailand Department of Fisheries, Kasetsart University Campus, Bangkok 10900 Thailand) and Claude E. Boyd (Department of Fisheries and Allied Aquacultures, Auburn University, Alabama 36849 USA). Volume 37, Number 1, Page 136, March, 2006.