Assessing New Technologies for Post-Harvest Treatment of Oysters
- TerrAqua
- Jun 3
- 2 min read
Updated: Jun 20
Shellfish aquaculture is the largest sector of U.S. marine aquaculture. As the industry expands, growers and regulators face increasing pressure to reduce illnesses caused by naturally occurring Vibrio bacteria, which become more prevalent during warmer months. Existing post-harvest treatments can alter the flavor and texture of oysters, are often unpopular with consumers, and are too costly for the thousands of small, independent shellfish farmers who dominate the industry.
One established food safety method, depuration, holds live shellfish in tanks of clean, flowing seawater where they naturally filter water and purge contaminants. While effective against coliform bacteria, conventional depuration has limited success in removing Vibrio, creating a need for more effective yet affordable post-harvest technologies.
We evaluated two complementary proprietary technologies to improve shellfish disinfection. The first uses an advanced water purification process that reduces suspended particles to nanoscale dimensions, while the second employs photocatalytic oxidation to generate and transport ozone and other biocidal gases into oyster tissues, where they destroy pathogens without harming the shellfish. Working individually or together, these technologies are designed to create conditions that are lethal to bacteria and viruses while preserving oyster quality and viability.
Although both technologies had proven successful in other industrial and aquaculture applications, they had never been tested with filter-feeding shellfish. Through pilot studies supported by Delaware Sea Grant and the technology developer, Puradigm, we established baseline data on oyster survivability and assessed their potential for reducing Vibrio, norovirus, and other pathogens in live oysters.
If successfully commercialized, this approach could provide the shellfish industry with an inexpensive, non-lethal, and consumer-friendly post-harvest treatment that improves food safety, expands market opportunities, and strengthens the long-term sustainability of shellfish aquaculture.
