The salmon industry faces significant challenges, including diseases caused by pathogenic bacteria. Two common culprits in salmonid aquaculture are Aeromonas salmonicida and Yersinia ruckeri. While vaccines offer a preventive measure, they can be expensive, logistically demanding, and their efficacy may vary.
A recent study published in Scientific Reports by researchers from Dalhousie University investigated the effectiveness of UV LED disinfection against Aeromonas salmonicida and Yersinia ruckeri, which affect salmonids. The researchers tested different UV LED wavelengths (255, 267, and 279 nm) and found that all wavelengths were effective in inactivating these bacteria.
Traditional Disinfection Methods
Traditional disinfection methods, such as chemical treatments and vaccination, have limitations. Chemical treatments can harm aquatic organisms and the environment, while vaccination can be costly and time-consuming. Additionally, the emergence of antibiotic-resistant strains of these bacteria further complicates disease control.
The Rise of UV LED Technology
Traditional bacterial inactivation methods, such as mercury-based UV systems, are energy-intensive, fragile, and often unsuitable for open aquaculture environments. In recent years, ultraviolet light-emitting diodes (UV LEDs) have emerged as a promising alternative. These compact, durable, and energy-efficient devices offer several advantages:
- Adaptability: UV LEDs can be easily integrated into various aquaculture systems, from closed containment facilities to open-water operations.
- Low Energy Consumption: Their low energy requirements make them cost-effective to operate.
- Environmental Friendliness: Unlike mercury-based systems, UV LEDs do not contain hazardous materials.
A New Study: UV LEDs as a Powerful Tool
A recent study investigated the efficacy of three UV LED wavelengths (255 nm, 267 nm, and 279 nm) in inactivating A. salmonicida and Y. ruckeri. The results were encouraging:
- High Effectiveness: All three wavelengths were effective in disinfecting both bacteria, even in a challenging wastewater matrix.
- Wavelength Superiority: The 267 nm and 279 nm wavelengths outperformed the 255 nm wavelength under both pure culture and wastewater conditions.
Challenging Environments
The study also examined the impact of particulate matter in wastewater on UV LED efficacy. Results showed that particulate matter reduced the upper treatment limit for A. salmonicida, but all wavelengths remained effective for disinfection in this challenging matrix.
This suggests that UV LEDs can effectively disinfect pathogens in real-world aquaculture environments where wastewater and other contaminants may be present.
Implications for the Salmon Industry
This groundbreaking research highlights the potential of UV LED technology to revolutionize disease management in aquaculture. By offering a reliable, efficient, and environmentally friendly solution, UV LEDs can help aquaculture producers reduce losses, improve the health and welfare of their stock, and ensure a sustainable seafood supply.
As technology continues to advance, we can expect to see even more innovative applications of UV LEDs in aquaculture and other industries.
Conclusion
This study represents the first use of UV LEDs to disinfect A. salmonicida and Y. ruckeri and provides valuable insights for aquaculture producers seeking to implement new disease control technologies. The results suggest that UV LEDs may offer a promising solution for disinfecting pathogens in aquaculture, providing a reliable and cost-effective alternative to traditional methods.
The study was funded by the Oceans Frontier Institute Seed Fund Grant.
Contact
Graham A. Gagnon
Department of Civil and Resource Engineering, Centre for Water Resources Studies, Dalhousie University
1360 Barrington Street, Halifax, B3H 4R2, NS, Canada
Email: graham.gagnon@dal.ca
Reference (open access)
Rauch, K. D., Bennett, J. L., Stoddart, A. K., & Gagnon, G. A. (2024). UV LED disinfection as a novel treatment for common salmonid pathogens. Scientific Reports, 14(1), 1-8. https://doi.org/10.1038/s41598-024-79347-6
