Visitas: 152
By: Ph.D. Stephen G. Newman*
As the science of aquaculture evolves, there is an increasing trend to move away from non-science-based production models to science-based models.
As the science of aquaculture evolves, there is an increasing trend to move away from non-science-based production models to science-based models. Sustainable production depends on reproducibility as well as the ability to ensure consistent production in the face of increased costs and market challenges.
In SE Asia, land constraints along with a high population densities have shaped the current face of shrimp farming. Farms are typically small, with ponds or tanks, lined with plastic with sumps or other means of readily dealing with accumulated waste.
“Heavy aeration is the norm, as are high stocking densities. In the Americas, farms tend to be much larger, not lined and stocked at lower densities. Waste cannot be collected with ease. Aeration, automatic feeders, and bioremediation are elements of the evolving model.”
Many studies corroborate that consumption of seafood is healthy and that when it comprises a significant component of the animal protein humans consume, it can extend longevity and overall quality of life.
This appears to be for seafood in general. As humanity has surpassed the 8 billion population mark and continues to add to this with no immediate end in sight, we are at or beyond the limits of sustainable fishing. Some would argue that we have exceeded the carrying capacity by our insatiable demand.
Few would not agree that the disruptions that are accompanying climate change are having an impact as well. If humanity is going to be able to enjoy the benefits of consuming seafood, aquaculture must continue to grow. This is not simple.
“There are powerful NGOs that see aquaculture as a point source for pollution not just of waste but also of residues of chemicals such as antibiotics. The major source of damage to aquatic ecosystems is the result of direct human activity and the totality of aquaculture does not even come close to this.”
Most of the world does not treat human sewage before dumping it into rivers, estuaries, and the world’s oceans. Many still end up dumping huge amounts of human waste when under engineered wastewater treatment systems are overwhelmed by rain.
Aquaculture is agriculture in an aquatic environment. Animals require proper nutrition and stress-free production conditions for optimum productivity. The world’s leading exporter is Ecuador has over 1 million MTs in 2022. China produces more than this, but little if any is exported, and they buy almost 2/3rds of the export volume of Ecuador.
Per capita consumption of seafood is variable, as it is in the US where the price of shrimp is not in line with consumer expectations.
Technification refers to the sum of tools that are used to increase overall productivity. Typically, the intent is to reduce the overall cost per unit of production and increase profitability. Unfortunately, this seems not to be as readily achievable as one would think.
Several challenges persist despite the move towards optimizing the production environment. The most challenging aspect of technification is recovering the costs of the changes in the value of the crop. The added costs of technology must be recouped by lowering the overall costs of production per animal.
“Perhaps the number one reason for this not being commonly realized is that disease is rampant despite a better understanding of where the problems originate and what we need to do about them.”
The widespread lack of understanding about the statistical nature of PCR testing (it is not a stand-alone technology) and a myriad of providers that either cannot grasp the nature of infectious disease or do not care and use terms like specific pathogen free (SPF) to mask the shortcomings in the processes ensure that this cycle will not be easily or readily broken.
There is strong evidence from the field that stocking pathogen free animals (APF-all pathogen free) can have a dramatic impact on profitability while the presence of even low levels of pathogens in typical production environments often leads to higher costs.
“The reasons for this are simple. Disease affects growth rates, survival rates, and feed conversion ratios. Slow growing animals take more time to get to market sizes. Low survival rates increase the production costs of those that survive.”
FCR’s are important elements of overall costs. When animals succumb at larger sizes, the feed that they consumed has been wasted, which skews the FCR´s.
Shrimp farming is one of, if not the most rapidly growing components of aquaculture globally. Current production is around the 5 million MT per year mark, with some signs of a moderate slowdown. There are many different production paradigms, and it seems that these are constantly being tweaked.
Basic business principles teach us that no matter how good a product or service one might have, there must be a demand for it. This can be existing demand or developed through marketing schemes. Failure to appreciate that as production increases the market demand will impact how sustainable the business is can lead to failure, as food is a commodity.
Ecuador is the world’s leading exporter of farmed shrimp. They have been able to increase production because of several things. Among these are:
✓ Improved genetics: Different sources of fast-growing shrimp with varying degrees of tolerance to disease.
✓ Aeration: Consistent use of aerators to maintain dissolved oxygen levels at or near saturation levels.
✓ Automatic Feeders: Great control of feed consumption ensures less waste and better consistency.
✓ Bioremediation: Use of Bacillus species to digest organic matter that accumulates as a natural by-product of the production process Ecuador chose some years ago to not control the presence of pathogens and to allow all of their animals to be exposed to whatever was present in the environment.
Some speculate that this APE (All pathogen exposure) approach is a part of this success as well. Unfortunately, since the use of technology to reduce stress and increase productivity is apparently essential for the continued growth of the industry, the presence of a myriad of pathogens that reduce the chances of successful crops ensures that recovering the added costs of these approaches may be challenging at best and not achievable at worst.
This is apparent at the moment when one looks at Ecuador’s success. Despite challenges with animal health, they are still able to produce animals for less than most of their SE Asian competitors. When disease reduces efficiency, the impact can be proportional to the overall investment in technology.
Small, lined ponds with high aeration rates (which equates to high electrical costs) stocked at hundreds of animals per m2 have little flexibility in terms of what the outputs must be to ensure consistent profitability. Larger, non lined ponds with less than 30 m2 stocking densities, aeration, automatic feeders, etc. have fewer added costs and a little more flexibility.
“Regardless, if the costs of technology are not returned in terms of lower costs of production, then financial losses will drive future growth.”
This is bad for those who fail, but not so for those who learn from their mistakes and adapt. This can drive consolidation, with stronger vertically integrated companies dominating. Supply side economics play a role in this. As levels of production increase and demand does not; there is downward pressure on the price.
Excess production invariably results in lower prices. These are natural cycles. When prices drop to the point that they have and additional costs are unavoidable (such as increases in costs of pumping and running aerators, security challenges, etc.) then the costs associated with technification must result in increases in efficiency that compensate for these increased costs.
“When this is not the case, then we see what seems to be happening. Farmers begin to lose money.”
If they are not highly efficient and biosecurity is not the highest priority, many will find that increasing densities using existing stocks is risky. Animals thrive in environments that are not stressful, although some stress can likely be beneficial.
Too much upsets the balance between prey (the shrimp) and predators (the obligate and opportunistic pathogens). The prey suffers and the farmer in turn suffers.
What can one conclude? The cost of using science-based tools to improve productivity must be offset by the additional profits that their use generates. If fundamental problems persist, specifically as discussed here, the fickle nature of the marketplace and the continued impact of disease wherever shrimp are being farmed, then the added costs of science-based approaches cannot be justified economically.
It would make more sense to revert to a very low input, low density production system using clean animals, which is what some are discussing. Moving back to producing tiger shrimp, Penaeus monodon. The wild types grow rapidly at low densities, although the threat of disease is still going to pose a challenge.
Stephen G. Newman has a bachelor’s degree from the University of Maryland in Conservation and Resource Management (ecology) and a Ph.D. from the University of Miami, in Marine Microbiology.
He has over 40 years of experience working within a range of topics and approaches on aquaculture such as water quality, animal health, biosecurity with special focus on shrimp and salmonids.
He founded Aquaintech in 1996 and continues to be CEO of this company to the present day.
It is heavily focused on providing consulting services around the world on microbial technologies and biosecurity issues.
sgnewm@aqua-in-tech.com
www.aqua-in-tech.com
www.bioremediationaquaculture.com
www.sustainablegreenaquaculture.com
