Dr. George Chamberlain on EHP

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Dr. George Chamberlain on EHP

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According to Dr. George Chamberlain, President of the Global Aquaculture Alliance (GAA), Enterocytozoon hepatopenaei (EHP), the disease that has emerged as a major risk to shrimp farmers in Asia, is unlikely to impact farmed shrimp production on the scale that early mortality syndrome (EMS) did.

Unlike EMS, EHP is caused by a spore.  This means that even though it spreads fast locally, it should be easier to contain it on a global scale, with the chance of it spreading to Latin America unlikely, said Chamberlain.

He said EHP is unlikely to decimate shrimp volume in the same way as EMS, because EHP—a microsporidian disease, caused by a spore rather than a bacteria or virus—generally does not cause mortality, but leads to severe growth retardation in heavily infected shrimp.  The effect of EHP—slower growth—isn’t noticeable until the shrimp reach 8 to 12 grams, at which point they are big enough for farmers to sell.  Chamberlain said EHP will make it harder to produce big shrimp, so we may see a trend toward more smaller shrimp coming out of Asia.

EHP is now present in China, Vietnam, Thailand, Malaysia and India, and possibly in the Philippines and Indonesia.  The EHP spore is resistant to chlorination, and it can spread quickly within a region from hatcheries to farms.

Chamberlain first observed EHP in Chinese shrimp, which he said have been hit the hardest and the longest.  Farmers there reported significant size variation.  “Size variation is normal…[but when] I looked at the Chinese shrimp, they showed me shrimp from 2 to 20 grams, an enormous difference,” said Chamberlain.  Normal size variation is generally between one and three grams.

EHP has not spread to the Americas, and, according to Chamberlain, there is hope that it will stay that way because of the nature of the disease and improved biosecurity measures.

EHP is killed by high temperatures and freezing, so in order for the disease to travel with the shrimp, they would have to be transported live, said Chamberlain.  He noted, however, that the disease can also be spread on live feeds, like marine worms, that are used in hatcheries.  “Live worms are often harvested from areas where shrimp farming occurs, so you can immediately see the cross contamination problem,” he said.  “One of the big challenges is to change our practices and discontinue the use of live worms.”

Source: Undercurrent News [eight free news reads every month].  Editor, Tom Seaman (undercurrent@undercurrentnews.com).  Chamberlain: New shrimp disease unlikely to hit production on scale of EMS.  Ola Wietecha (ola.wietecha@undercurrentnews.com).  November 9, 2015.

Missouri – GAA to Offer Training Modules on EMS and EHP

The first educational modules of the program — which will be aimed at teaching shrimp farmers how to manage and eliminate early mortality syndrome (EMS) and Enterocytozoon hepatopenaei (EHP) — are currently being developed and will be launched on the GAA-funded Responsible Aquaculture Foundation’s (RAF) website (responsibleaqua.org) once they are completed, most likely by the end of the month.

“In the interest of time, we plan to launch the initial modules about EMS and EHP as quickly as possible directly on the RAF website,” George Chamberlain, GAA president, said.

Some of the courses offered will be free, said Chamberlain, including the initial EMS course as “there is an industry-wide need for help on EMS right now.”

The more comprehensive learning management system software the other modules will use will take longer to develop, but will likely be ready by early 2016.

For now, Chamberlain said the lessons will be focused on disease management with the main targets being shrimp farmers, but the program will not stop there.

Future topics will depend on a survey to determine what the industry thinks is most pertinent.

The modules will function much like other online classes, and will “present the various lessons and modules, track the lessons completed by each student, issue certificates, and perhaps offer higher levels of recognition within curriculum areas”, Chamberlain said. The courses will be mostly reading-based, but will also include photos and videos and students will be evaluated by quizzes.

– See more at: http://aseanseafood.net/2015/11/gaa-funded-classes-on-ehp-ems-management-in-shrimp-farming-coming-soon/#sthash.t9qvpBYU.dpuf

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