** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** OFF-FLAVOR--THE PRESENCE OF MUSTY OR EARTHY ODORS OR FLAVORS CAUSED BY GEOSMIN (GSM) AND 2-METHYLISOBORNEOL (MIB)--IS AN ISSUE FOR FARMED FISH. OFF-FLAVORS CAN REDUCE PRODUCT VALUE AND/OR INCREASE PRODUCTION COSTS BY NECESSITATING OPERATIONAL CHANGES OR TECHNOLOGIES TO PREVENT OR CORRECT OFF-FLAVOR.STUDIES HAVE BEEN CONDUCTED TO ASSESS STRATEGIES TO ADDRESS OFF-FLAVORS, BUT EXPERIMENTS ARE GENERALLY CONDUCTED OPPORTUNISTICALLY WITH FISH KNOWN OR ASSUMED TO BE OFF-FLAVOR. IN SOME CASES, THE STARTING TISSUE LEVELS OF GSM AND MIB ARE TOO LOW TO BE PRACTICALLY RELEVANT; IN OTHER CASES, EXTREMELY WIDE VARIATION IN STARTING LEVELS COMPLICATES INTERPRETATION AND APPLICATION. HYPOTHESIS TESTING AND INNOVATION TO ADDRESS OFF-FLAVORS IN FARMED FISH IS CONSTRAINED BY THE ABSENCE OF PREDICTABLE EXPERIMENTAL MODELS.WE PROPOSE TO REFINE A PROTOTYPE MODEL OF OFF-FLAVOR WE DEVELOPED IN RAINBOW TROUT (RBT) AND EXTEND THIS MODEL TO ATLANTIC SALMON (ATL). USING THESE MODELS, WE WILL ASSESS DIETARY AND WATER TREATMENT-BASED STRATEGIES TO ADDRESS OFF-FLAVOR IN FLOW-THROUGH AND RECIRCULATION AQUACULTURE SYSTEM (RAS) ENVIRONMENTS.OBJECTIVE 1: FURTHER DEVELOP AND VALIDATE FLOW-THROUGH MODELS OF OFF-FLAVOR IN RBTOBJECTIVE 2: DEVELOP AND VALIDATE RAS MODEL OF OFF-FLAVOR IN ATLOBJECTIVE 3: USING THESE MODELS, OPTIMIZE PURGING STRATEGIES AND ASSESS EMERGING TECHNOLOGIES FOR MITIGATION/CORRECTION OF OFF-FLAVOR IN RBT AND ATLTHE PROPOSED WORK WILL ADDRESS PROGRAM AREA PRIORITY C. IMPROVING THE QUALITY AND EFFICIENCY OF PRODUCING MEAT, MILK, EGGS, FISH, AND ANIMAL FIBER BY INFORMING OFF-FLAVOR RESEARCH BROADLY AND DEMONSTRATING HOW RESEARCHERS AND FARMERS CAN ADDRESS THE PROBLEM OF OFF-FLAVOR MORE RIGOROUSLY AND EFFECTIVELY.