NEW: Tool that can prevent and treat EMS Download paper on EMS prevention using field and lab proven tools.
We recently tested an all natural form of a selected glycerol fatty acid ester that was shown some years ago to selectively kill Vibrio parahaemolyticus strains. The test results showed that the material definitely inhibited the overall growth of vibrios significantly when compared with control tanks. Top dressing the feed was enough to prevent EMS and reduce total vibrio loads in the experimental tanks significantly.
Contact us for details.
EMS, now known as AHPNS or AHPND, is a serious problem affecting shrimp farming in China, Thailand, Vietnam, Malaysia, and Mexico. Based on a wide range of field observations, an in depth review of the relevant literature, I have written an article that discusses what I believe is happening, why it may have happened, and what possible approaches might be useful in mitigating the impact of this disease.
We have lab tested a compound with anti-vibrio properties that shows promise as a tool for dealing with EMS. This tool can be milled into or onto feed at a reasonable cost and is GRAS in the US. It is widely consumed in human foods.
The article entitled "What can Shrimp Farmers do about EMS?" is at this link.
SPF or SPR?
On one of the many discussion groups that populate the internet, a subject that generated some stimulating discourse dealt with some of the terms that are in common use in shrimp farming today, notably the terms SPF and SPR as they refer to shrimp. Rather than find myself in the middle of a quagmire of dissenting opinions about what these acronyms actually mean, I have written a small opinion piece that while I am sure will stimulate more discussion, should lay some of the myths to rest once and for all. The article, entitled " Shedding some light on the confusion about SPR and SPF." can be found at this link. Please feel free to read and reproduce it, although with the limitation that you still credit the author.
I head to Ecuador and Peru on Sunday for 11 days of selling and networking. Ecuador and their neighbors are reaping the rewards that are coming from a tumultuous shrimp farming sector. EMS has taken a third of the global annual tonnage of farmed shrimp off of the street and the subsequent economic impact has favored those who still have shrimp to sell. Prices are at or near record highs with little chance of this changing anytime soon. It is the new year and some are optimistic that EMS will wane. Others are not so. After all there is no sign of this waning anywhere in the last 4 years so what is different about 2014? We are just beginning to gain insights into how this bacteria produces disease, where it is in the environment, how it is spread, what, if anything, we can do to slow it down and can we even stop it? Tools for sensitive detection of the bacteria are in use with more under development. These tools are still in their early stages of use and some tweaking may be in order to improve specificity. At this time no one should consider that they have the problem if all they have is PCR. This does not mean that this should be ignored. Strains need to be tested for virulence in biosecure bioassay laboratories.
NEW: A presentation (Is it possible to control the bacterial composition in shrimp and fish ponds?) I gave in Vietnam has been published and is available along with the entire proceedings from the workshop:
Proceedings of the Biofloc Technology and Shrimp Disease Workshop
December 9-10, 2013 Saigon Exhibition and Convention Center, Ho Chi Minh City, Vietnam by clicking this link.
The big story today is still EMS. This pathogen is unlike any other that has ever affected shrimp farming and its global impact is far from over. Reports from India, specifically MPEDA's comments suggest that EMS is in India. Based on the picture that I have, I think that there is little hope that any type of external controls will stop this problem from spreading. There are reports that suggest that it is occurring in lower salinity waters for the first time from which one can infer that perhaps we are dealing with multiple strains. If this is the case and a simple exchange of genetic material (say through a plasmid) is all that is needed to confer virulence then the only solution will be a paradigm shift. I actually discussed this some months ago and now some are beginning to see that this might be part of the solution.
If anybody reads these comments and wants to know more, e-mail me through the contact information page or send a direct e-mail to email@example.com or firstname.lastname@example.org.
I just posted an article on EMS (AHPNS do AHPND) that discusses some very interesting observations that have been made by groups that are in the field living and working with the problem and how this information tells us something about what may be going on. Three points are evident:
1. The disease is spread in a manner that is similar to how cholera is spread.
2. The role of biofilm formation and toxin production are paramount to the disease process.
3. Prevention will require surveillance and proactive management of the presence of the pathogen or a major change in the current shrimp farming paradigm will be required to mitigate its impact. Curing the disease once it occurs will not be simple although there are a range of tools that could be potentially be useful.
Been a long time since I commented last. Finally in December of 2012 my pain (after a second operation in August) all but went away. It is slowly crawling back though and the future is uncertain. I am however able to travel again and after spending most of 2012 at home and far too much of it in bed, I am glad to be traveling (sort of).
The big story in shrimp farming is EMS or AHPNS as is it is more accurately characterized. This disease has literally brought the shrimp farming industry to its knees starting in China and progressing through to Thailand today. It continues to spread. It has been determined to be infectious and is likely bacterial although it does not seem to behave like a classical bacterial infection. The HP is damaged by a toxin which in turn allows secondary bacterial infections to kill the shrimp. Given the rapidity with which the problem develops it makes sense that it may be present in some stocks at the time of stocking. Reports are that the disease is manageable but it remains to be seen if this is anecdotal. I have written several articles about this and as soon as the nature of the pathogen becomes public information will talk about what control options might exist.
Being bed-ridden on and off for the last five months has not been conducive to aggressively working, but has been a time for reflection. My first experience with pond production of warmwater species came in the late 1980's and I wondered if producers understood how many toxins were produced by various bacteria (including what we commonly call blue green algae). I thought that it seemed a huge risk to me to produce animals in these environments. In all of these years since then, I have never heard of an instance where humans fell ill to what could be attributable directly to any known toxin. Most people are aware of the toxins that produce off-flavor, geosmin and 2-methylisoborneol (MIB) being the most widely known. Few though have heard of BMAA (β-Methylamino-L-alanine). This is closely related to alanine and is a nonprotein amino acid. It has been found far and wide and there are several studies that suggest it may be associated with Alzheimers disease, Parkinsons Disease and even ALS. While the links are not causal in the sense that there is a postulated mechanism with experimental proof, the evidence is strong enough to create some significant concerns. Nobody looks for this toxin in farmed fish and farmed shrimp.
Another toxin that people only associate with fugu poisoning, tetrodotoxin, can be produced by many different bacterial species, including commonly occurring vibrios. I am not saying that I think that either of these toxins are necessarily causing problems. What I am saying is that these are not problems that should be ignored. True sustainability must take factors like this into account and responsible farming practices absolutely must include the consideration that these, and as we become aware of others, do not belong in any product that we eat.
WSSV in shrimp farms is once again damaging Mexico. This is a recurrent annual program and there are some indications that this virus is mutated in some areas to being able to produce disease at higher water temperatures. Used to be that anything above 31 C was a sure way to deal with the virus.
It is unfortunate that many companies continue to be impacted severely by this virus. There is solid evidence that it can be controlled effectively provided one is willing and able to invest in the correct tools. There are no magic bullets and while there are a startling number of papers that show materials with short term benefits, it is highly unlikely that any of these will be highly successful in the field.
EMS in shrimp farms or early mortality syndrome is taking its toll in SE Asia and spreading. Based on years of observing the industries in these countries, it is highly likely that this will continue to get worse until the underlying causes of these problems are addressed. We are polluting the oceans. Last year there more than 500 areas that were characterized as dead zones. There are likely thousands of areas where we are in the early stages. We are dumping vast amounts of high nutrient loaded metabolites (untreated sewage, agriculture run off from feed lots, industrial pollutants and effluent from aquaculture farming operations) into the oceans and this is resulting in nutrient loads that encourage the growth of algae that produce toxins.
My surgery alleviated the leg pain although other back pain persists. I am fully recovered and heading on the road again in a little while. It has been 6 months since I flew last, the longest I have gone in a decade or more without traveling. I am continuing to blog and you can see a list of recent blogs under the publications tab to the left.
I want to take this opportunity to thank all of my customers and clients and wish all of you a joyous and Happy New Year!
Year end reflections: As this year draws to a close, I am struggling with some health issues and have to undergo back surgery in ten days to "fix" an arthritic vertebra. I can only hope that the intractable pain that has become a part of my life will be fixed. Many interesting issues have been on the forefront of aquaculture this year and I have commented on some of these in magazine articles and a blog for Seafood Source. com.
My latest blog and the last one for the year focused on a witch hunt that we should be ashamed of. Many published studies support the notion that Americans are becoming all the more distanced from the realities in the world around them and that education is leaving the population unable as a whole to make rational decisions. There are more examples of this available than I can cite in this small space but there is one that I want to drive home.
Seafood Source describes the ten biggest Seafood stories in Europe and North America for 2011 in the usual year end ruminations. Among them is the travesty that AquaBounty is being forced to endure. Taking the lead in the production of a genetically engineered salmon this company has been persecuted and is currently fighting for its very existence against quite literally a Salem witch hunt mentality. I encourage you to educate yourself in this matter and to take the time to understand the issue. There is so much irrational fear that this fish will harm its consumers and the environment that it is scary. This obsession is pointing out how easily our political system is manipulated and how seemingly educated individuals are far from it. There are forces at work here that will ensure that the US will become a second or third tier player in the years to come. Fear mongering combined with outright lies and distortion of the facts is never in ones best interest and given how weak the political system in the US has become is it becoming inevitable that we will be relegated to a backwater status? For more information, click here.
The month ends. I decided a few weeks ago, at the last moment to go to Ecuador after many years. I was well received as were my new products. My fingers are crossed that I will be able to follow up with this. Ecuador is practicing strictly low density (extensive) culture with some companies such as PescaNova looking at trying intensification on a small scale. A couple of the talks were quite interesting. CP Thailand's Robins McIntosh talked about what was going on in Thailand. Thailand has successfully intensified the production of white shrimp in conjunction with what is likely the most extensive family selection based genetics program in the world. They currently have families of shrimp that grow 1 gram per day; that's right, one gram per day, not per week. While this is under extremely controlled conditions it shows that there is a tremendous potential with this shrimp. I do not have a crystal ball but I will predict that within three years there will be shrimp farms in SE Asia where a full blown production cycle will be 60 days or less and that the costs of production will drop far below South America's current low cost extensive production paradigm.
I just read that the Department of Natural Resources of the state of South Carolina is concluding that the "accidental" release of Tiger shrimp some years back off of the coast of South Carolina could not have resulted in these shrimp becoming permanently established off the coast and elsewhere. Tiger shrimp are not native to this hemisphere yet there are now stable populations off the cost of Brazil, South Carolina and elsewhere. I wonder if we might be able to look to some of these for founder stocks of SPF Monodon? Apparently the record for production of this shrimp in a farm outdoors is 23 MT per ha or so. I can not help but think that if we can get 1 gram a day from L. vannamei, we might be able to get 2 or more per day from P. monodon. Seems to me that perhaps this should be the shrimp that the next decade focuses on.
I have had some interesting queries this month and a very interesting discussion about a "new" technology that claims that it will revolutionise shrimp farming in the USA. Using the principle of stacking shallow tanks on top of each other, actually a technology that has been employed for decades in some sectors but which had not found itself into shrimp farming, claims are being made for incredible yields. The technology is patent pending and has been licensed to a third party for distribution rights. The only problem is that the individual claiming that he discovered this forgot to mention that he did no such thing. In fact it is not his idea at all and he copied most if not all of it.
Go to http://www.akvaplan.niva.no/aqua/research/raceways.asp and see for your self. The Shallow Raceway System devloped by AKVA holds a great deal of promise although it remains to be seen jsut exactly how much.
I have been invited to speak at a conference in Beijing, the 4th Algae World ASIA conference, on the use of byproduct algal meals as potential substitutes for fish meal. http://www.cmtevents.com/aboutevent.aspx?ev=111143&
Interested in knowing the truth about certification of aquaculture projects? Contact me through our contact information page and we can talk about it. You will be shocked to learn the truth.
I have been asked by several investors if I know of projects that might be suitable for them to invest in. Of course I am aware of lots of projects that can use money, though few that would use it to move forward in the manner that I believe that they must for long term sustainability. Contact me if you are interested. This should give me an idea if anybody actually is reading this. :)
Breaking News for April 2011
The virus that causes White Spot is wreaking havoc for the first time in Saudi Arabia. The largest farm in the country has been wiped out and the virus is spreading. What can be done in the face of this? As a marine microbiologist with an indepth understanding of the nature of disease outbreaks in marine animals I can tell you that typically the first reaction in the face of this is one of awe at the ability of this virus to cause so much damage in such a short period of time. Given that this virus has been causing disease problems in many parts of the world for more than a decade there is no reason to sit back and wait it out.
My advice in matters of this nature is fairly straightforward. There are tools that can be used to mitigate the impact and we understand a great deal about how this virus produces disease and what approaches are potentially of use.
THERE ARE NO MAGIC BULLETS.
There is nothing that one can feed to or treat your animals with that will prevent or cure the problem. PCR is widely used as diagnostic tool to ensure that broodstock do not carry the virus. This can be misleading though and there are published observations which show that PCR negative animals are not necessarily free of the virus. Relying heavily on PCR is not wise. Screening PLs using PCR is also potentially very risky. We have outlined some of the tools that we have developed and or market over the years that can help. Click here to take you the publication entitled, Tools for Dealing With WSSV.