2007 Annual Report 1a.Objectives (from AD-416) Develop feeding management strategies and diets for optimal growth, efficiency, and reproductive success of high-value marine finfish reared in low salinity recirculating systems. Develop year-round spawning strategies for captive broodstock and larviculture methods for sustainable seed production of high-value marine finfish species. Develop engineering processes and sustainable effluent technologies to enhance water and energy utilization and reduce environmental impacts within, and discharged from, low-salinity recirculating aquaculture systems. 1b.Approach (from AD-416) Design and construct replicated recirculating aquaculture systems (RAS) to evaluate efficiency of current RAS technology components (i.e., pumps, biofilters, microscreen and swirl solids separators, oxygen saturators, SCADA units) for the production of marine finfish in low salinity environments. Conduct waste excretion and solids velocity studies for different stages (fingerling-juvenile-broodstock) of selected marine fish to establish baseline information for recirculating system design and component sizing. Develop suitable dynamic system models of RAS processes and components to determine cost-effective production output. Evaluate the utilization of wood fiber materials for the removal of ammonia and suspended solids of the organic effluent from recirculating systems in efforts to achieve enhanced water re-use. Determine the nutrient digestibility of traditional and non-traditional feed ingredients to replace fish meals and oils, and evaluate the efficiency of diets containing these ingredients in terms of growth, performance, health, nutrient partitioning, and carcass quality. Establish nutrient requirements for the development of broodstock diet to increase egg and larval quality resulting in enhanced reproductive success and reduction of reproductive stress. Determine nutrient and energy requirements for rearing pompano, black sea bass, and flounder in low salinity environments for optimal growth, performance, health, nutrient partitioning, and carcass quality. Establish and refine spawning procedures including hormonal induction, photothermal manipulation, and sex ratio modification to achieve year-round reproduction of target broodstock species such as black sea bass pompano. Develop procedures for consistent production of larval through juvenile stages of selected species via research involving physiology, stocking density, water quality, and physical factors of culture systems. 4.Accomplishments PERFORMANCE OF LOW-SALINITY RECIRCULATING AQUACULTURE SYSTEM: Juvenile Florida pompano were raised to market-size in a low salinity production-scale recirculating system, and the system components evaluated for efficiency of waste removal, and water and energy use by scientists at the ARS Sustainable Marine Aquaculture Project in Fort Pierce, FL. Low-salinity recirculating systems can eliminate the need for marine aquaculture to be located near limited and expensive coastal land thereby expanding opportunities for marine aquaculture; however, little information exists regarding efficient operation of low-salinity recirculating systems. Pompano were reared for 300 days from 30 g to 620 g, and the efficiency of ammonia removal, feed and waste particle removal, and oxygen, water, and energy use were monitored on the system components as increasing amount of feed inputs were used to maximize fish growth. The accomplishment provides culturists and engineers baseline performance and design criteria over a complete growout cycle for the construction of production-scale recirculating systems to produce market-size marine fish in low salinity. (NP106: Components 6f and 8b, Aquaculture Production Systems, culture of marine species in low-salinity water, Sustainability and Environmental Compatibility, water use and reuse) PRODUCTION OF MARKET-SIZE POMPANO IN LOW-SALINITY: Production characteristics and body composition of Florida pompano reared from juveniles to market-size at two different densities in low-salinity recirculating systems were determined by scientists at the ARS Sustainable Marine Aquaculture Project in Fort Pierce, FL. Non-scientific observations suggest pompano have the potential to be reared at varying densities in low salinity environments; however, no published information exists on this topic. Juvenile pompano were stocked into commercial-scale low-salinity recirculating aquaculture systems at two initial culture densities and reared for a period of 110 days, resulting in the production of fish of suitable size for wholesale and retail markets. The accomplishment establishes the feasibility of rearing market-ready pompano in low salinity recirculating systems while identifying the effect of varying culture densities on fish production characteristics and body composition, thereby allowing established and developing commercial pompano aquaculture operations to implement this production format. (NP106: Components 6b and 6f, Aquaculture Production Systems, production intensity, culture of marine species in low-salinity water) TEST DIET TO DETERMINE NUTRIENT REQUIREMENTS FOR POMPANO: A test diet for the determination of nutrient requirements for pompano was developed by scientists at the ARS Sustainable Marine Aquaculture Project in Fort Pierce, FL. Identification of nutrient requirements specific to pompano will increase the rate and efficiency of growth while reducing waste excretion; however, before these requirements can be determined a suitable test diet is required that is acceptable to the fish and results in normal growth. A test diet was developed using milk protein and nutrient supplementations that was well accepted by the fish and resulted in comparable growth to fish fed a high quality fish feed. The accomplishment allows determination of pompano nutrient requirements to assist in developing less expensive and more environmentally responsible diets. (NP106: Component 6d, Growth, Development, and Nutrition, nutrient use and feed evaluation) EVALUATION OF AIRLIFT TECHNOLOGY: Rate of oxygen transfer to water, removal of dissolved carbon dioxide, and water flow using various air to culture water ratios were evaluated by scientists at the ARS Sustainable Marine Aquaculture Project in Fort Pierce, FL. Use of airlift technology for water flow in recirculating systems has potential to reduce electrical costs as well as simplify system design and operation. Defined air to culture water ratios and lift-to-submergence ratios for optimum air transfer and water flow rates in airlift pipes were evaluated using different diameter pipes ranging from 4 to 8 inches. The accomplishment provides technology to aquaculturists for an alternative low energy, relatively inexpensive, simple, and efficient recirculating system that represents a substantial cost savings over traditional recirculating aquaculture systems. (NP106: Components 6f and 8b, Aquaculture Production Systems, culture of marine species in low-salinity water, Sustainability and Environmental Compatibility, water use and reuse) UTILIZATION OF SOY PRODUCTS IN POMPANO DIETS: Plant-based alternatives to fish meal for use in Florida pompano diets were evaluated by scientists at the ARS Sustainable Marine Aquaculture Project in Fort Pierce, FL. High quality fish meal is the best source of protein for fish; however, replacement of fish meal with alternative protein sources will increase sustainability and profitability of the aquaculture industry. Soybean meal and soy protein isolate were fed to Florida pompano at increasing rates of 0 – 100% replacement of fish proteins in the feed. Based on survival, growth, and efficiency, it was demonstrated that pompano effectively utilize feeds with fish protein replacement of up to 80% with soybean meal and up to 20% with soy protein isolate. The accomplishment allows fish feed manufacturers to substitute these feed ingredients for fish meal, resulting in less expensive and more environmentally responsible diets. (NP106: Components 6c, 6d and 8a, Growth, Development, and Nutrition, sustainable sources of nutrients, nutrient use and feed evaluation, Sustainability and Environmental Compatibility of Aquaculture, aquaculture feeds) DIETARY ENHANCEMENT OF ROTIFERS: Growth, survival, and fatty acid composition of larval Florida pompano fed live feed organisms (rotifers) supplemented with various commercial enrichment diets was determined by scientists at the ARS Sustainable Marine Aquaculture Project in Fort Pierce, FL. A major bottleneck to the production of marine fish larvae is that larvae require live feed organisms of high nutritional value until they reach the juvenile stage of development. Larval pompano were fed rotifers enriched with various commercial rotifer diets. Results indicate that pompano larvae perform better when fed only a select few available rotifer enrichment diets. The accomplishment establishes protocols for the optimal feeding of early stage larval pompano that can immediately be implemented by the commercial aquaculture sector increasing larval fish survival and quality. (NP106: Component 5e, Reproduction and Early Development, early life stage development and survival) EVALUATION OF SUBSTRATES FOR AMMONIA REMOVAL CAPACITY: The rate of ammonia removal using two different types of substrate in a submerged nonmoving biological filtration unit was evaluated in a low-salinity culture environment by scientists at the ARS Sustainable Marine Aquaculture Project in Fort Pierce, FL. Bacteria used for removing ammonia from recirculating aquaculture systems grow on substrates with different capacities to remove ammonia from the system. Two different substrates were evaluated in a low salinity environment receiving low rates of feed inputs and no differences were detected between the substrates in terms of their capacity to remove ammonia, despite substantial differences in price. The accomplishment provides aquaculturists and design engineers an alternative substrate for use in filters to remove ammonia from recirculating systems at a substantial cost savings. (NP106: Components 6f and 8b, Aquaculture Production Systems, culture of marine species in low-salinity water, Sustainability and Environmental Compatibility, water use and reuse) 6.Technology Transfer Number of non-peer reviewed presentations and proceedings 8 Number of newspaper articles and other presentations for non-science audiences 12 Review Publications Weirich, C.R., Stokes, A.D., Smith, T.I., Jenkins, W.E., Denson, M.R. 2006. Outdoor tank and pond spawning of cobia rachycentron canadum in coastal South Carolina. Journal of Applied Aquaculture. 18(3):1-16. Weirich, C.R., Riche, M.A. 2006. Tolerance of juvenile black sea bass centropristis striata to acute ammonia and nitrite exposure at various salinities. Fisheries Sciences. 72(5):915-921. Riche, M.A. 2006. Analysis of refractometry for determining total plasma protein in hybrid striped bass(Morone chrysops x M. saxatilis) at various salinities. Aquaculture. 264:279-284. Weirich, C.R., Smith, T.I., Jenkins, W., Denson, M.R., Stokes, A.D., Tomasso, J.R., Chappell, J., Burnside, D. 2007. Cobia aquaculture research in South Carolina, USA: Captive reproduction, pond nursery production, and selected environmental requirements and juveniles. In: Lino, I.C., Leano, E.M., editors. Cobin Aquaculture: Research, Developments, and Commercial Production. Asian Fisheries Society, Fisheries Society of Tiwan, and World Aquaculture Society. p. 19-44. Weirich, C.R., Groat, D.R., Reigh, R.C., Chesney, E.J., Malone, R.F. 2006. Effect of feeding strategies on production characteristics and body composition of Florida pompano reared in marine recirculating systems. North American Journal of Aquaculture. 68(4):330-338. Weirich, C.R., Riley, K.L. 2007. Volitional spawning of Florida pompano, Trachinotus carolinus, induced via administration of Gonadotropin Releasing Hormone Analogue (GNRHA). Journal of Applied Aquaculture. 19(3):47-60. Pfeiffer, T.J., Lawson, T.B., Church, G.E. 2007. Engineering considerations for water circulation in crawfish ponds with paddlewheel aerators. Aquacultural Engineering. 36(3):239-249. Pfeiffer, T.J., Ludwig, G.M. 2007. Small-scale system for the mass production of rotifers using algal paste. North American Journal of Aquaculture. 69(3):239-243.