Since 2014, aquaculture has provided more fish for human consumption than capture fisheries, and it is expected to account for approximately 60% of the total fish and shrimp available for human consumption by 2030 (FAO, 2020). But although farmed seafood can help meet the global need for protein in a way that wild capture fisheries cannot, aquaculture—including shrimp farming—comes with its own set of complex and interrelated challenges.  

In order to produce shrimp in a way that is both economically and ecologically sustainable, shrimp robustness is key. A robust shrimp is less susceptible to disease and infection and better able to manage handling, transfer and environmental fluctuations. Disease compromises performance, yield and product quality. It also generates a host of ancillary costs in terms of diagnostics, treatment, feed conversion ratio, time and labor as well as market reputation. Disease is always bad for business.

Reducing mortality rates and improving lifetime performance improves return on investment and reduces the environmental burden of operations. To achieve this, shrimp farmers need to pay close attention to the requirements of the animals themselves, to the action of pathogens upon them and to the quality of the space in which they live.

A three-pronged approach

Stress predisposes animals to disease, but a robust host is less susceptible to illness. Improving host robustness is therefore key to minimizing the negative potential of stress in shrimp farms. Support for the host via appropriate nutrition is essential, but so too are proactive management of pathogens and control of the environment. A three-pronged approach is therefore a prerequisite for sustainable shrimp farming. At DSM, our unique portfolio of solutions for shrimp aquaculture covers these three areas, providing a holistic response to the ‘disease triangle’ represented by host, pathogen and environment.

Nutritional support for the host

There is no single intervention that, used in isolation, can ensure shrimp health; any approach must be multifactorial. Good nutrition is an essential element, however, and DSM’s Optimum Vitamin Nutrition™ (OVN™) is fundamental in providing this.

OVN™ is about feeding animals high-quality vitamins in the amounts and ratios appropriate to their life stage and growing conditions. Vitamins C and E have an especially important role to play in shrimp health, although others should not be underestimated. The appropriate vitamin intake helps build a robust host by strengthening the immune system and building stress resistance, thereby improving health and performance as well as meat quality.

Functional health additives such as Rovimax® NX Plus, meanwhile, provide all-important nucleotides. Consisting of a nitrogen-containing base, a phosphate group and a sugar, nucleotides have a range of beneficial effects such as increasing feed intake, improving gut health and supporting gill, liver, spleen and kidney function (Hossain et al, 2019). Important in the choice of a nucleotide solution is the proportion of free nucleotides, i.e., nucleotides not attached to ribonucleic acid (RNA) and therefore fully bioavailable to the shrimp. Rovimax® NX Plus from DSM – the leading free nucleotide solution on the market – offers highly pure and balanced nucleotide content.

Another valuable functional health additive in the DSM aquaculture portfolio is Levabon®, a combination of β-glucans and mannan oligosaccharides, with enhanced bioavailability. These work in cooperation to enhance the immune system and improve resistance to disease and stress.

Mycotoxin management

Another threat to the health of farmed shrimp is the presence of mycotoxins in feed. Mycotoxins are secondary metabolites produced by fungi. They attack the hepatopancreas, an important organ for immunity, compromise the immune system, and interfere with the integrity of the gut, increasing its permeability and facilitating the entry of pathogens. Our state-of-the-art Mycofix® product line uses multiple deactivation approaches to remove these contaminants, and its (Nguyen et al, 2021) safety and efficacy is proven by seven EU authorizations.

Pathogen control

Vibrio is a genus of ubiquitous bacteria found in a wide variety of aquatic and marine habitats. For this reason, Vibrio species constitute a major part of the shrimp microbiota, even in healthy animals.

Certain Vibrio species can produce toxins that attack the hepatopancreas, causing high mortality in shrimp. Unmanaged, their growth can quickly reach dangerous levels. An additional threat to shrimp health is caused by biofilms – thin, resistant layers of bacteria that settle upon and coat various surfaces.

The quality of the pond environment can be maintained by three interventions: direct inhibition, toxin reduction and quorum quenching (reducing communication between bacteria). This can be achieved through the use of probiotics (Kesselring et al, 2019). 

DSM offers a portfolio of solutions addressing various aspects of pathogen and biofilm control. Our Biotronic® and AquaStar® ranges directly inhibit the growth of pathogens and degrade toxins that attack gut and hepatopancreas tissues.

Management of the environment

Like all marine creatures, shrimp live in an intimate relationship with their environment. The water that surrounds them is as vital to their health as the air that we breathe. If the quality of their aqueous habitat is compromised, whether by pathogens or toxic metabolites, their health--and their performance--will be compromised. Sustainable shrimp farming requires careful management not just of the shrimp themselves but also of the environment in which they are farmed.

High stocking densities and inputs of artificial feed can have a deleterious effect on water quality, not least because of the accumulation of waste matter or ‘black sludge’ at the bottom of aquaculture ponds. The breakdown of organic inputs forms toxic metabolites such as hydrogen sulfide, ammonia and nitrite and is time-consuming and expensive to remove manually. Active management of sediments is as important as active management of the pond water itself.

AquaStar® from DSM is the most complete set of aquaculture bioremediation tools on the market. Its multi-species approach builds on synergies and complementary modes of action between different bacterial species. AquaStar® Pond (comprising multi-strain beneficial bacteria) improves water quality by reducing pathogen load, while AquaStar® PondZyme (consisting of beneficial bacteria plus an enzyme blend) improves water and sediment quality by reducing organic matter in the pond.

Conclusion

Shrimp robustness requires careful management and the use of specific tools in judicious combination. Building robustness starts at the hatchery and continues until harvest. There are many points along this journey where it may be threatened, but there are also many opportunities to intervene proactively to minimize those threats.

As the world’s fastest-growing animal protein sector, aquaculture has the potential to deliver huge benefits in terms of production output, nutritional value and financial returns. DSM’s comprehensive portfolio of aquaculture solutions can pave the way for the transformation of the global aquaculture industry into a sector that is healthy, thriving and sustainable by any measure.