UV LED Technology: The new weapon against aquaculture diseases

A team of researchers from Dalhousie University in Canada has conducted a ground-breaking study evaluating the effectiveness of UV LED in disinfecting common pathogens in aquaculture, focusing specifically on salmon farming. The research targeted two bacteria that pose a constant challenge to the industry: Aeromonas salmonicida and Yersinia ruckeri, known to cause furunculosis and enteric redmouth disease, respectively.

UV LED technology marks a significant step forward in both safety and sustainability, offering a viable alternative to traditional mercury-based UV lamps.

These new devices are not only environmentally friendly but also offer greater energy efficiency and adaptability to a variety of settings, including recirculating aquaculture systems (RAS).

It's worth noting that the European Union, as part of its commitment to environmental sustainability, has legislated a ban on the manufacture, import, and export of mercury UV lamps. This prohibition will come into effect from the 31st of December 2025 or 2026, depending on the lamp category.

The shift towards UV LED devices is expected to provide a versatile and cost-effective solution, aligning with the EU's climate and public health objectives.

Key Findings of the Study

The study tested three UV LED wavelengths: 255, 267, and 279 nm to assess their pathogen inactivation capabilities.

The technology was evaluated in two scenarios: pure cultures and complex wastewater matrices. Initially, the bacteria were cultivated under controlled, sterile conditions before being exposed to varying doses of UV radiation via a specialised LED device.

Researchers measured disinfection effectiveness by counting the surviving bacterial colonies post-UV exposure. To replicate real-world conditions, they also introduced municipal wastewater samples, which are rich in organic matter and particulates, to assess how these variables impacted the disinfection performance of UV LEDs.

The findings were striking, demonstrating that wavelengths of 267 and 279 nm were more effective, achieving near-complete disinfection of both bacteria at relatively low UV doses. Even in the challenging context of wastewater, where UV penetration is hindered by shadowing effects, the UV LEDs maintained significant disinfection efficacy.