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August 10, 2015

United States

Washington State—Dr. Stephen Newman on EMS


Dr. Stephen Newman, a microbiologist and president and CEO of Aqua-In-Tech, which specializes in aquatic animal health, has posted an update on early mortality syndrome (EMS) to his webpage.  Here are some excerpts from the update.


Based on what we have observed and been told, we suggest that shrimp farmers consider the following:


Do not use PLs from hatcheries that use broodstock held in outdoor ponds unless testing definitively demonstrates a very low to no load of the etiologic agent.  A competent, well-trained microbiologist who understands how to ensure that the testing is realistic and meaningful must do the testing.  It is too easy to miss this organism using conventional approaches.  PCR (polymerase chain reaction) must target the toxin’s genes.


In areas where farms can be dried out, do so.  Dry out all inlet and outlet canals.  Remove any accumulated organic matter in the ponds.  If you can work with your neighbors, try to coordinate an area-wide dry-out, and if intake canals can be dried, do so.  The use of lime (to elevate the pH) and sun drying, combined with tilling (8 to 10 inches minimum), should eliminate most of the bacteria.  Not drying out poses a serious risk.  You should expect the problem to get worse as organic materials accumulate and the Vibrio produces large amounts of toxin.


Divide large ponds into small ponds.  It is easier to control stress and inputs in small ponds.  Large ponds are affected as readily as small ponds.  As organics accumulate remove them.  It’s harder to keep ponds with dirt bottoms free of organics.  Smaller ponds can be engineered with sumps and aeration systems that push the accumulated organics into an area where they can be pumped out.  Bioremediation (probiotics) should be focused in these areas, which can be very heavily contaminated.  The organics must be hauled off or destroyed.  The less time they are in the pond, the less time there is for growth of the toxin producing strains.  Stocking density is not a factor.  EMS is not an infectious disease.  


Information: Dr. Stephen G. Newman, President and CEO, Aqua-In-Tech, Inc., 16715 56th Avenue West, Lynnwood, Washington 98037, USA (phone 1-425-787-5218, email, webpages and


Information: For a full copy of this report CLICK HERE, and then on the words “Download File”, which is under the words “EMS Update August 2015.pdf”.  You will also see the titles of other PDFs on EMS that you can download from this location.


Source: Aqua-In-Tech’s Webpage.  EMS Update.  August 2015.

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