SYMBROSIA AIMS TO SELECTIVELY BREED THE NEXT GENERATION OF A PROMISING NEW ALGAL CANDIDATE FOR INCLUSION IN RUMINANT LIVESTOCK FEED. WHEN SUPPLEMENTED AT JUST 0.5% IN CATTLE FEED, RED MACROALGAE ASPARAGOPSIS TAXIFORMIS HAS LED TO OVER 90% REDUCTIONS IN METHANE EMISSIONS, A SIGNIFICANT CONTRIBUTOR TO CLIMATE CHANGE. IN FACT, LIVESTOCK METHANE IS ONE OF THE FEW SOURCES OF GREENHOUSE GASES THAT STILL DOES NOT HAVE AN EFFECTIVE, COMMERCIALIZED, TECHNICAL MITIGATION STRATEGY. ADDITIONALLY, A. TAXIFORMIS HAS THE POTENTIAL TO IMPROVE LIVESTOCK HEALTH BY PROVIDING ESSENTIAL NUTRIENTS AND MINERALS. THROUGH THE COURSE OF THIS SBIR PHASE I PROGRAM, SYMBROSIA WILL BREED RESILIENT AND HIGH-YIELD LINES OF THIS MARINE ALGAE TO IMPROVE COMMERCIAL FEASIBILITY AND REDUCE IMPLEMENTATION COSTS FOR THOSE IN AGRIBUSINESS KEEN TO REDUCE SUPPLY CHAIN EMISSIONS. KEY TRAITS TO BE IMPROVED WITHIN THE SPECIES INCLUDE SPECIFIC YIELD AT A VARIETY OF TEMPERATURE THRESHOLDS AND CONCENTRATION OF THE ACTIVE ANTI-METHANOGENIC COMPOUNDS IN THE TISSUE. SYMBROSIA WILL COMMERCIALIZE RESULTING STRAINS AT HAWAI'I FACILITIES AND PROVIDE SEED TO DOMESTIC PARTNERS FOR GROW-OUT.