We can grow better shrimp and in better ways
China is obviously the major world player, both pushing and pulling the market as a producer and importer, and the country needs massive imports from Ecuador and other suppliers to satisfy its huge internal demand. Thailand continues its strong recovery from EMS/AHPND, through the increased use of improved genetic lines, enhanced production techniques and to some extent the expansion of its domestic market. Ecuador appears on track to meet or exceed its impressive 2015 production.
Aquaculture in general – and certainly the shrimp farming industry – faces several challenges including diseases, feeds, environmental and social responsibility, the marketplace, investment, leadership, consumer awareness and education.
I believe diseases and feeds are probably the most important ones for the shrimp industry right now. In its relatively short history of around 30 years, it has been periodically affected by various diseases, mostly of viral origin and including the Taura and White Spot viruses.
In the last few years we have seen the emergence of two new, serious ones, the EMS/AHPND disease (Early Mortality Syndrome/Acute Hepatopancreatic Necrosis Disease) caused by a bacterium, Vibrio parahaemolyticus; and a new disease called Hepatopancreatic Microsporidiosis (HPM) caused by a small (1 micron), intracellular, spore-forming microsporidian parasite (Enterocytozoon hepatopenaei, or EHP).
We are definitively learning to manage both, and the case of Thailand coming back strongly from the significant impact of EMS/AHPND is a good example. Diseases have been an important part of the industry since its early years, and will certainly continue to have an impact, but we have accomplished the quadrupling of global production of farmed shrimp in only about 20 years despite a number of diseases, and I believe the industry will continue to live with and learn to manage diseases as it continues expanding.
The other challenge I think is very important is that of aquafeed ingredients. Aquaculture – including shrimp farming – has expanded very significantly in the last 30 years or so, and needs to continue growing in order to contribute the very large volumes of seafood needed by our growing human population. Several major aquacultured species that must continue playing an important role in feeding people are fed with manufactured aquafeeds, which means the aquafeed industry also needs to grow significantly, and this will increase the need for more ingredients. Although cultured algae may have a role, I believe the large majority of additional ingredients will come from various land-based activities like agriculture, through increased production of major current ingredients like soybeans and other crops, from processed animal by-products, and from new ingredients like diverse bacterial products, insect meals and others. Land-based production of feed ingredients under largely controlled conditions is expandable, sustainable, responsible and certifiable.
Regarding industry perspectives, I see three basic questions we should ask and answer. The first one is “Can we ‘make’ a better shrimp?” My view is, most definitively yes.
The most widely cultured species, the Pacific white shrimp (Litopenaeus vannamei), and also the still very relevant black tiger shrimp (Penaeus monodon) have amply shown their potential to grow significantly, and domesticated lines have demonstrated substantial genetic gains in growth rates, resistance and other desirable selection traits. The relatively short generation time (versus other aquacultured species) is a plus in their selective breeding efforts. Of special importance will be their further domestication, the development of improved lines of specific pathogen-free (SPF), specific pathogen-resistant (SPR and specific pathogen-tolerant (SPT) animals, and breeding for improved performance in specific culture environments. Also very important, in my opinion, will be the increased use and application of the -omics technologies like genomics, nutrigenomics, proteomics and others in our young industry.
The second question to consider is “Can we grow shrimp better?” Again, yes.
We have the tools and they keep getting better, as well as new ones being developed. In the growout technologies we can increase water reuse and biofloc technology, and increased use of multi-phased production with nursery systems. We can grow the industry going inland, near major consumption centers. Nutritional research is further expanding our understanding of shrimp’s nutritional requirements, the relevance of their gut health, with innovative ingredients and improved feed manufacturing processes, with novel, functional feeds (seasonal, stress, immunomodulation, others), with improved delivery/management of feeds including precision feeding.
In the health-management area, we can improve effective biosecurity including looking at the larger picture with zone management; research is continuously improving pathogen detection and providing a better understanding of their mode of action; the effective use of immunostimulants and probiotics can be even more very significant, and ongoing research has shown that even the development of “vaccines” now appears not so far-fetched.
And my third question is “Can we grow the shrimp market?” Definitively. But we need to offer consistent availability and quality, as well as more, novel value-added, “convenient” products.
We must work harder to reach the fast-food sector and increase our presence in the domestic markets of many countries. New technologies like those that can extend the shelf-life of fresh products (e.g. modified atmosphere packaging) could revolutionize how we market our products. We know we have a great story to tell, and we must tell it better and to a wider audience.
I believe we can expect the trend of global production of farmed shrimp to continue. The main trends include more efficiency at every level of production and marketing, and increased industry consolidation. Important R&D issues are faster-growing, more disease-resistant animals developed for specific growing conditions. Additional product characteristics (e.g. higher w-3 content) would be a plus for marketing and increasing consumer demand.
The main hatchery issues are Artemia availability and prices, increased replacement of live feeds, and biosecurity. Important growout issues include shortening the period of days of culture through selective breeding, production efficiency and management; and improving biosecurity, health management and survival.
The market issues include expanding consumption (new markets, internal/external); development of new value-added products; and meeting increasing consumer expectations regarding wholesomeness, sustainability and responsibility. The industry has significant potential to expand global production, both through the development of new locations and by responsible intensification of production technology and procedures.
Linking stress to disease
On the topic of shrimp diseases, Dr. María Soledad Morales-Covarrubias of Centro de Investigación en Alimentación y Desarrollo, A.C. (CIAD, Mexico) discussed the current situation of various diseases of farmed shrimp – including those caused by bacteria, protozoans and viruses, as well as others – in Central America. She presented results of the incidence of these diseases from sampling programs throughout the region, and concluded that “…the risk of these diseases requires the creation and implementation of efficient management schemes that interrelate the organism with the water, soil and food, resulting in a minimum of stress.”
Dr. Sonia Soto, also from CIAD Mexico, presented a detailed overview of infectious diseases in farmed shrimp in Mexico. She reviewed the history of shrimp diseases in the country, and diagnostic methods and technology for the major bacterial and viral pathogens. She also discussed the phenotypic characterization of the bacterium strain (Vibrio parahaemolyticus AHPND+) involved in early mortality disease or acute hepatopancreatic necrosis disease (AHPND) in Mexico, and among her conclusions she stated that there are “Vp primary pathogen strains with different virulence, that toxins in the plasmid have the ability to infect local strains, that there are slight differences between Mexican and Asian strains, and that pathogenic strains can tolerate a wide range of environmental conditions.”
As alternatives to control AHPND, she recommended “maintaining the density of Vp below de infectious level of 104 CFU/mL; the use of closed nursery systems with low water exchange and the use of probiotics and biofloc technology; the application of stringent sanitation measures in laboratories producing shrimp postlarvae; to avoid the use of antibiotics and generic probiotics; and the use of shrimp genetic lines.”