Aquaponics, an integrated aquaculture and hydroponic system, is a popular sustainable agriculture system due to higher nutrient retention efficiency and lower water requirements. Little, however, is known about nitrogen transformation and its ultimate fate in aquaponics systems. Researchers at the University of Hawaii are using a $499,000 AFRI grant to correlate nitrogen transformations with environmentally relevant microbial processes. They discovered that tomato, pak choi, and romaine lettuce were the best plants to grow for recycling nitrogen waste from fish tanks. They also found that controlling dissolved oxygen in biofilters and fish tanks and that controlling the feed-to-plant ratio at neutral pH were the best ways to increase nitrogen utilization efficiency and reduce the nitrogen loss in aquaponics systems. A team of researchers from Washington State University and University of Idaho used a $325,000 grant from the NIFA-supported University of Washington-based Western Regional Aquaculture Center to investigate Coldwater Disease in salmon and trout. The team found a way to combat the disease by using the fish’s own gut bacteria as a probiotic to limit economic losses to the worldwide $13.7 billion salmonid aquaculture industry.

NIFA originally published this impact in the NIFA 2016 Annual Report. Want to read about more impacts like this? Check out Fresh from the Field, a weekly bulletin showcasing transformative impacts made by grantees funded by NIFA.