Volume 1-5  April 2020

Shrimp farms in Ecuador Oct 2019.  Many of these ponds are fallowed today because of Covid-19.

We appreciate those of you that sign up for this newsletter although our statistics suggest that most are not reading it.  If this trend continues, we will discontinue it and consider another approach.  It is time consuming to put these letters together and if few read it, there is little point in continuing.  We hope that those of you that do read it are gaining useful information from it.  Aquaintech Inc. wants to help you be better shrimp farmers.

Covid-19 is impacting all of us and we are far from certain as to how much of an impact will take place.  We are in the early stages of a global pandemic that could eventually take millions of lives and will have profound disruptive impacts on the global economy.  This is not a virus to trifle with.  Take what is happening seriously and protect yourself to the extent that you are able to.  Being young does not automatically ensure that you will not be seriously impacted if you catch it.  Shrimp farming is being impacted as are most similar activities that depend heavily on exports.  Please take extra care in these times. 

Did you know?

Some Facts About Probiotics

There is a widely agreed upon definition of probiotics.  "Living bacteria consumed orally that alter the microbiome with an impact on the host's health."  Probiotics do not exist for shrimp or fish.  They may not even exist for human beings.  Someone decided that the term could be extended to microbial preparations that act on the environment which no expert in the field will agree is a legitimate use of the term.  We are still in the earliest stages of being able to characterize microbiomes.  What is apparent so far is that any given mircrobiome is highly variable.

I wrote an article, entitled “Microbiome Manipulation in Shrimp Fact or Fiction?” about this.   Most of the bacteria that make up a given microbiome cannot be cultured.   There is a mad rush to alter the microbiome and claims abound as to what these impacts are.   Correlation is not causation.   This is not simple or straightforward as the focus is on the very small percentage of bacteria that can be cultured as possible candidates for altering the microbiome.   Since 99.9% of the bacteria cannot be cultured (yet-if ever), we have a long way to go until we will actually be able to alter the microbiome in a manner that is consistent and beneficial to the animals in the sense that a true probiotic would have to be.     

Most, if not all, of the products being sold for use as probiotics, at least in shrimp farming, are really tools for degradation of the organic matter.   They may inhibit the growth of algae and some bacterial species as well, primarily by competition for nutrients.  They do not however fit the definition of a probiotic.   For shrimp, short intestinal tracts with rapid passage times from mouth to the pond bottom and the ingestion of detritus ensure that this is not going to happen.    Any colonization would be short term as the constant evolutionary pressure that is being placed on the microbiome that causes it to shift and change in response to inputs from the environment ensures this. 

This biodegradation is an important process and can have dramatic environmental impacts when Bacillus based products are used properly.   The term properly refers to applications that are done as needed and not constrained by the cost of using the product.  Frequent applications are not necessarily the best approach to take.   Some culture and grow out various blends of bacteria, often without any understanding of the risks that they are taking and no quality control at all, to pour into their ponds daily or every few days.   Adding a massive dose of living bacteria to a pond all at once is not going to solve the underlying water quality issues that the intent of adding them supposedly addresses.   The water quality will not get any better any quicker than adding PRO4000X tablets periodically.   Adding a very large amount of actively metabolizing bacteria to a pond environment all at once and frequently might seem like a good idea.   However, you are adding many more bacteria at once than you want.    Nutrients limit growth and whatever nutrients are present ensure that most of these bacteria die off very quickly. 

The failure to mention that these products actual work via bioremediation and insist on using the term probiotic is inaccurate and potentially misleading.    When you hear the word probiotic the first thought that many have is that this impacts animal health, as this is what is claimed for human beings.   It is still far from clear that this is actually what occurs in human beings.    There is no evidence that these tools function, largely, as anything but as a means for bioremediation of organic matter, despite claims to the contrary.   Caveat emptor.        

The Best Tool for Biosecurity?

I have written a few times about the testing services that Genics Pty. Ltd is offering.   They can test samples for 13 pathogens using real time PCR for less than $50.00 (exclusive of cost of getting samples to a lab that can do the testing) for all 13 pathogens.   I recently wrote an article for Aquaculture Magazine on the logic of requiring all broodstock producers to test each individual animal to cull those out of the population that are carrying pathogens that can be transmitted to PLs either vertically or horizontally.   For this price, although the sellers might not like it, it will ensure that they are not selling animals carrying specific pathogens.   

Some argue that this can be accomplished by testing PLs.  This is simply not true.  In my opinion, it demonstrates a lack of understanding that PCR when used the way that it is used in aquaculture is a statistical tool.   When large populations are being tested (such as the millions of PLs in a larval rearing tank), a negative PCR test only means that the sample is negative.   Even with a random sample and a 100% accurate testing methodology, there could be 2% of the animals carrying a pathogen.    More than likely this is not just 2% since it requires sampling and testing 150 individual animals, and nobody does this.  When tissues are pooled, the virus present is diluted.    This 2% has been confounding shrimp farmers since the advent of PCR.   It continues to offer a false sense of security to many others who fail to understand the critical limitation of this tool.  

There is simply no excuse not to focus on controlling pathogens from entering the production systems.   While this will not eliminate all diseases and does nothing to stop those forces that shape the next pathogen it can dramatically improve production in responsibly managed paradigms.  Furthermore, if one insists on generating high levels of natural productivity via symbiotics, etc.  it can also serve to lessen the risks as outlined below.  

The diagram below outlines the process.  Contact Genics or Aquaintech Inc. for more information.

Symbiotics, Synbiotics, and Aquamimicry

Enlightened or a Sword of Damocles?

Many shrimp farmers are resorting to the use of strategies that are intended to increase natural productivity via the use of fermented substrates that are incubated, typically with commercial preparations of bacteria, on pond side.    I have been fairly vocal about the potential risks.   There are several that could be catastrophic.   Under some circumstances this can be an effective tool, however it cannot reduce the potential impact of disease.   This can only be done through proper biosecurity. 

Damaged pond bottom from use of synbiotics.

It seems to me that there is a serious memory lapse here.  For years I have been teaching farmers that the best approach to disease management is to ensure that no pathogens are coming in via the PLs.  This cannot be accomplished solely through the use of PCR, although there are many who would tell you otherwise.   They are wrong.  Farmers will lose millions of dollars and refuse to address this issue.   Often, I hear, we cannot do what we know needs to be done.  It costs too much, etc.  Ultimately, the cost of protecting oneself would be much less than the constant impact of preventable diseases on the bottom line.

Paraphrasing the philosopher George Santayana, “Those who cannot learn from their mistakes are condemned to repeat them.”   Why do I think that this is applicable to any approach that encourages the development of natural productivity?   It has been well documented for decades that many vibrio species readily attach to the chitinous surfaces of a wide range of zooplankton.  It stands to reason that cultural practices that encourage the production of zooplankton could result in issues with the presence of vibrios that attach to their surfaces.  There is strong evidence to support that this attachment can facilitate the interchange of genetic material and indeed has been shown to be a critical element in the conversion of non-toxigenic strains of Vibrio cholera into toxin producing strains.  There is also solid evidence to show that similar transformations may occur with other vibrios, including Vibrio parahaemolyticus and Vibrio harveyi, both important pathogens of farmed shrimp and fish. 

It stands to reason that practices that encourage the unrestricted growth of vectors might not be prudent in the long run.   The OIE, in their Aquatic Health Manual, detail vectors that can carry the WSSV.  The virus does not appear to replicate in them however it can persist, and they can readily transmit the virus.  Many are what can be found in synbiotic and aqua-mimicry environments.  This poses a potentially serious threat and ensures that eradication of the virus is not straight forward.  Killing all of the vectors through the use of caustic pesticides results in a temporary drop in the levels of WSSV, but within a few weeks the quantities return to pre-treatment levels.

WSSV is endemic in most shrimp rearing areas of the world.  Efforts to keep it out of broodstock have been widely ignored.  Many do not seem to appreciate the temperature dependence of the infectious process.  When the temperatures are high, above 31 C or so, the virus cannot replicate and is rarely a problem.  Below this temperature, it does replicate and there are innumerable instances where farmers believe that the virus is not present only to find out that this is not even remotely the case when animals are moved from warmer to cooler temperatures.   Once an outbreak occurs and the temperature remains under this threshold, many different vectors will pick up the viable virus as it is excreted by affected animals.  This includes rotifers, copepods and many others. 

WSSV is an example that should have taught the industry a lesson.   There will be new viruses appearing as the industry grows.   If farmers refuse to take reasonable steps to lessen their ability to impact them, you can bet that there will be massive losses with the subsequent fallout. 

For those of you who think that they are OK because they are not having “problems”, think again.   You are gambling with your future and it is highly improbable that given the nature of the global shrimp farming community that you will not eventually pay the price.  It is risky at best to be encouraging the development of natural feeds in uncontrolled production environments.  While I think that these production paradigms do have some merit, encouraging the growth of bacteria without quality control is alone foolish (ask most who work with bacteria and understand how they work why this is a bad idea).  Add to this that you are encouraging the growth of vectors that can carry pathogenic vibrios attached to them as well as one of the most costly viruses ever to impact shrimp farming and it appears clear to me, at least, that the risks in the long run easily outweigh any short term benefits.

Pond side culture without QC is inviting a disaster.

Intensification with the elimination of vectors and high degrees of control over inputs (high levels of REAL biosecurity) is the path forward.  There will always be some risks unless production is in indoor environments with massive amounts of control.

FRAUD IN VIETNAM

As a small company finding reputable companies to work with can be quite challenging.   We made a mistake in India by trusting when we should not have and there are many who hold me personally responsible for the decision that I made despite the fact it was an honest mistake.   After working with a distributor in Vietnam for the last 5 years or so who was selling our PRO4000X and AquaPro lines exclusively we discovered that Than Vuong was not being honest with us.  They committed to purchasing a given volume in writing and then did not follow through.  With full knowledge of the consequences they deliberately sabotaged us and purloined our trademarked names. 

They are no longer affiliated with Aquaintech Inc. in any manner.  They have been told to cease and desist but it does not appear that this is the case.  They signed a contract acknowledging that these specific actions would cause us considerable financial harm.  Yet they did it anyway.  These are, in my opinion, NOT the actions of an ethical company. 

Genuine high-quality Aquaintech Inc. products cannot be purchased from them.  We are currently looking for a company to work with to replace them.   We have several companies we are working with to do this.  For the time being though please contact us directly for our products.