Protecting the health of farmed aquatic species: Prioritizing investment in research on diseases and epidemiology

Six causes behind complex disease outbreaks

According to Dr. Truong Dinh Hoai, Deputy Dean of the Faculty of Fisheries and Head of the Aquatic Disease Research Group at the Vietnam National University of Agriculture, aquaculture diseases have become increasingly complex, posing one of the greatest barriers to the stable development of the industry. Several key factors contribute to this situation:

First, Vietnam’s aquaculture sector is extremely diverse in cultured species, including crustaceans (shrimp, crabs), fish (coldwater, freshwater, and marine species), and mollusks (babylonia snails, oysters, clams, etc.). Each environment hosts multiple species and farming models, such as open systems (cages in rivers, lakes, and the sea), pond culture, polyculture, and many more. Each species faces both common and species-specific diseases, while new and dangerous pathogens continue to emerge. This diversity, combined with varied environments and farming practices, makes disease management and monitoring highly challenging.

Second, the number of specialized professionals in aquatic disease management remains very limited, hindering effective and synchronized control. Meanwhile, the sheer scale of aquaculture operations makes nationwide disease surveillance and prevention difficult, especially in offshore or remote areas. As a result, management effectiveness and farmer support often fall short of expectations.

Third, problems persist in broodstock and seed quality. Despite efforts in breeding and genetic selection, Vietnam has yet to achieve full independence in supplying high-quality seed for aquaculture. Imported broodstock, while offering faster growth and economic benefits, also brings risks of transboundary diseases if not carefully monitored.

Selective breeding for disease resistance has not kept pace with industry demands. Genetic degeneration after many generations is also increasingly apparent in some species. For example, Vietnam once had shrimp seed with excellent disease resistance, but after about ten years, resistance has declined noticeably. Meanwhile, developing disease-resistant strains requires long-term (5–10 years) and costly research.

Fourth, environmental pollution and climate change are growing threats to aquaculture development. Many intensive and super-intensive farming models operate at very high densities, but lack effort in terms of waste treatment, hence the degrading water quality and habitats. Combined with harsher climate impacts, aquatic animals show declining immunity, making disease outbreaks more severe and harder to control.

Fifth, farmers’ awareness of proactive disease prevention remains limited. In aquaculture, the guiding principle is “prevention first, then comes timely treatment.” Since shrimp and fish live in water, an environment with constantly shifting physical and chemical factors, disease outbreaks are often detected late, making treatment difficult and less effective. Without proactive prevention, farmers are essentially at a disadvantage from the start.

Sixth, the misuse and overuse of medicines and chemicals during the caring stage have already contributed to environmental pollution and the rise of antimicrobial resistance, resulting in less effective preventive measures and more difficulties in the treatment process.

Too few scientists specialize in aquatic diseases

In addition to the above causes, the aquaculture industry faces a severe shortage of human resources and tools for disease management. “There are already few fisheries experts, and those with deep expertise in aquatic diseases are even rarer, countable on one hand,” Dr. Hoai remarked. This mismatch runs counter to the sector’s critical role in agriculture and exports.

The vast diversity of species and farming models across the country makes it nearly impossible for managers, researchers, and technical staff to comprehensively monitor field conditions. Currently, surveillance systems, early warning networks, and IT applications for aquatic disease management remain underdeveloped. The thin pool of specialists further slows responses and hampers support efforts.

More than strengthening on-the-ground technical teams in key farming regions, Dr. Hoai deems it crucial that Vietnam establishes a roadmap for developing disease surveillance and early warning systems, along with user-friendly reporting software. It is also essential to invest in research, compilation, and dissemination of practical manuals on proactive disease prevention for common cultured species, while expanding training activities through agricultural and fisheries extension agencies.

Dr. Hoai said, “In reality, many long-time farmers remain conservative in their disease management practices and do not yet trust science. Therefore, we must intensify outreach to raise awareness of proactive prevention. However, outreach must innovate, moving away from dry, academic approaches and instead focusing on real people, real cases, and model farms that have clearly demonstrated improved productivity and economic value.”