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August 21, 2013


Update on EMS/AHPNS


The following exchange took place on The Shrimp List, a mailing list for shrimp farmers.  Part of a discussion on “Dinoflagellates and Ammonia Control”, it provides a good update on the status of EMS/AHPNS in Thailand.


Freek Huskens ( Daniel, greetings from a struggling Tilapia farmer in Indonesia who’s attempting to do some shrimp as well.  How are things in Thailand these days?  Have you found a solution to the EMS/AHPNS problem?


Daniel Gruenberg ( Hello Freek, EMS/AHPNS is still rearing its ugly head and affecting production at most farms.  The industry here is eerily silent on the EMS situation, and I only get information from our own farms and friends who own farms.


EMS/AHPNS seems to come and go like a roller coaster.  Many farms I know have been fooled into thinking they have it licked only to have a rude awakening with the next crop.


I have been very frustrated at the lack of cooperation from the academic labs here in Thailand and overseas.  They seem to move at a snails pace.  After failed negotiations with several labs and government institutions, we have made the bold step of building our own facilities to do disease challenge experiments.


It is extremely difficult to say you have a solution without a PCR test to confirm your positive controls.  Unfortunately, the reality is that a solution to EMS/AHPNS is probably worth billions of dollars, so all players are keeping their cards very close to their chests.


As I have lamented many times before on this list, the lack of sharing of knowledge, even on the basic issues surrounding the expression of the disease, is causing damage in the billions to the entire industry.  Too bad we cannot cooperate more.


Dallas Weaver ( Daniel, the lack of cooperation on the EMS issue is a result of viewing ones self interest very narrowly.  One of the ironic strengths of places like the Silicon Valley in California, USA, has been the rapid flow of ideas, often by people moving from one company to another, in spite of all the intellectual property lawyers.


If the shrimp industry viewed the larger reality that it is in the “meat” business and competing with chicken/pigs/cows/fisheries, it becomes clear that if a solution to EMS spreads through the industry, it will mean relative  growth for everyone in the shrimp sector.  At the present time shrimp is a minor player relative to the other “meat” producers, however we have an inherent efficiency advantage in terms of feed conversion ratio (FCR).  We can produce more “meat” with less feed.  Shrimp don’t expend energy to stand up or stay warm.


That means we could, in theory, provide “meat” to the coming three billion more people on this planet and to the two billion who want more meat in their diets, and we could do it without requiring more agricultural land for producing feedstuffs. Aquaculture could provide two to three times more “meat” yield using the feedstuffs (minor reformulations) that are presently going into chickens/pigs/cows.  We have an FCR advantage and often a meat yield advantage.


Let’s understand who our real competitors are—not the farm next door—but the chicken/pig/cow farmers of the world.  While outcompeting traditional farmers, we can help improved the environment by reducing the amount of land required to produce feed.  We have much more to gain through cooperation with each other than by gaining a six-month lead over the neighboring shrimp farm.


Daniel Gruenberg ( Dallas, that’s an interesting point of view!


As far as EMS/AHPNS is concerned, we continue to collect anecdotal data that indicate diatoms/copepods are effective way to ameliorate the effects of EMS in shrimp ponds.  I call this data anecdotal at the moment due to the lack of accurate tests.  We cannot afford the luxury of just controlling one variable at a time in a commercial situation, so it’s impossible to say what exactly is having an effect, but we are making inroads in controlling the disease.  With the completion of our own disease challenge facilities, we hope to pick up the pace of discovery.


Diatoms are the best possible plankton structure for both tilapia and shrimp for many reasons, including stabile water quality and improved nutrition.


Dallas Weaver ( The nice thing about diatoms is that it is easy to shift the silicate balance in the pond to favor diatoms.  You don't have that leverage with algae, and many algal species are either toxic or non-digestible (tough cell walls and immune to consumption by zooplankton).


Source: The Shrimp List (a mailing list for shrimp farmers).  Subject: Dinoflagellates and Ammonia Control.  August 20, 2013.


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