World Aquaculture December 2020

WWW.WA S.ORG • WORLD AQUACULTURE • DECEMBER 2020 49 has a long history with mahi-mahi over the years, following extensive research activities in the wake of the Deepwater Horizon oil spill in 2010, utilizing this species as a model for assessing crude oil impacts on high-value and ecologically-important pelagic fish species. Optimizing Aquaculture Production Technologies Through Physiological and Bioenergetics Research The development of hatchery technology for marine species is only part of the equation in developing viable commercial-scale aquaculture operations. University of Miami aquaculture researchers use advanced techniques and technologies to optimize production of marine fish. Through bioenergetics and physiological research it is possible to determine the optimal culture conditions throughout the life cycle of each species. We have been conducting studies aimed at assessing the impacts of environmental conditions on metabolic endpoints in species across all life stages, including assessment of swimming metabolism, through the use of swim tunnel respirometry and energy partitioning. Such work has allowed for quantification of environmental and energetic requirements under site- and system- specific conditions, thereby allowing for optimization of system design, operation and production management. One example is a recent collaboration with Open Blue Sea Farms for studying energetics and swimming speeds to understand the effect of offshore currents on metabolism and growth of cobia for optimized production. Research activities in this area also allow for design and operation of production systems that offer improved sustainability, such as integrated multi-trophic aquaculture (IMTA) systems that exploit waste production from higher trophic level species for production of other crops at lower trophic levels that also have market value. Findings from this physiological and bioenergetics research, along with improved understanding of energy flows, are critical to optimize the production process while helping improve the overall efficiency, sustainability and profitability of marine finfish aquaculture. Nutrition Research Aquaculture nutrition research at UM is driven by the needs of the commercial sector, which is also the primary source of funding for this research. In a commercial marine finfish operation, feeds can represent as much as 70 percent of the production costs, of which a majority is used on fish near harvest size. Hence, we work primarily with near harvest-size fish, aiming at finding solutions for the stages where 80-90 percent of all feeds consumed in a production cycle are used. There is a need and strong demand for the development of ecologically efficient, economically viable and nutritionally adequate diets for commercially important tropical and subtropical marine finfish species. Our nutrition programworks closely with the commercial sector to conduct practical research, such as digestibility trials, to improve the ecological and economic efficiency of aquafeeds. Further, in addition to probiotics, we are studying and conducting research with bacteriophages, organic acids, essential oils and trace minerals to improve fish health. Over the years, the UMAquaculture Program has been conducting extensive nutrition trials with multiple marine fish species Late-stage cobia embryos. Newly-hatched yolk-sac larvae of red snapper. Red snapper embryos. ( C O N T I N U E D O N P A G E 5 0 )