@article{gibson_watanabe_losordo_whitehead_carroll_2020, title={Evaluation of chemical polymers as coagulation aids to remove suspended solids from marine finfish recirculating aquaculture system discharge using a geotextile bag}, volume={90}, ISSN={["1873-5614"]}, DOI={10.1016/j.aquaeng.2020.102065}, abstractNote={Traditionally used in the construction and excavation industries to remove solids from runoff, geotextile fabric tube (Geotube) technology has been adopted by freshwater aquaculture facilities as a method of effluent management. The effectiveness of a Geotube is improved by using chemical polymers to bind suspended solids in the effluent for greater retention; however, polymers used in freshwater systems may not be effective in marine systems. Using laboratory jar tests, seven organic polymers of different molecular weights and ionic charges were evaluated at doses ranging from 0 to 50 ppm for solids removal efficiency (SRE) from effluent from a marine (33 ppt) finfish RAS growing black sea bass. Of the seven polymers screened, two cationic high molecular weight polyacrylamide polymers Drewfloc (DF) 2449 and DF 2468 had high SRE of total suspended solids (TSS) (36.1–84.4 %). Further tests using miniature geotextile bags confirmed that DF 2449 at 10 ppm and DF 2468 at 5 ppm had high SRE (73.3–75.9%) compared to the untreated control (43.4 %). When applied to a commercial-scale Geotube, DF 2449 at 10 ppm removed 92.1 % of the TSS in the effluent of the marine finfish RAS growing black sea bass. Rinsing the saline biosolids with freshwater at a rate of 1.63 L per 100 g dry solids reduced the salinity to < 1 ppt, a level safe for land application, while 4.43 L per 100 g dry solids were needed to reduce the salinity to 0.16 ppt. Geotube systems are effective at removing TSS from intensive, marine RAS discharge as well as meeting NPDES discharge compliance and reducing the impact of aquaculture on local waters.}, journal={AQUACULTURAL ENGINEERING}, author={Gibson, Tyler F. and Watanabe, Wade O. and Losordo, Thomas. M. and Whitehead, Robert F. and Carroll, Patrick M.}, year={2020}, month={Aug} }
 @article{guerdat_losordo_delong_jones_2013, title={An evaluation of solid waste capture from recirculating aquaculture systems using a geotextile bag system with a flocculant-aid}, volume={54}, ISSN={["0144-8609"]}, DOI={10.1016/j.aquaeng.2012.10.001}, abstractNote={Two separate geotextile bag systems were evaluated as a means for capturing and dewatering bio-solids in the effluent stream from recirculating aquaculture systems (RAS). Each geotextile bag system used a high molecular weight cationic polyacrylamide (PAM) polymer as a flocculant-aid. The two systems were operated under freshwater and brackish water conditions. A complete analysis including water quality and agronomic sludge analysis was conducted at the North Carolina State University Fish Barn – a large-scale, freshwater RAS demonstration and growout facility. An evaluation of water quality and performance of a similar geotextile bag system was also conducted at the Marine Aquaculture Research Center near Marshallberg, North Carolina, USA, under brackish conditions (15 PPT). Results indicated that performance of each of the systems was similar with TSS, COD, TN, and TP removal greater than 95%, 65%, 50%, and 38%, respectively, for both systems. Analysis of the sludge collected in the freshwater system after 70 days in a dewatering, inactive mode, showed a moisture content (MC) of 86%, or 14% dry matter (DM), indicating the system was effective at passively dewatering the bio-solids. Nutrient removal efficiency may be system specific based on the geotextile bag size and influent flow rate. Geotextile bag systems using flocculant-aids are an efficient means for capturing and dewatering waste solids from RAS effluents. Optimized geotextile bag system designs depend on flow rate, feed rate, and solids dewatering time, and fate of the treated effluent. This evaluation will aid in predicting the expected performance and determining the appropriate size of a geotextile bag system. The type of treatment required downstream from the geotextile bag system used for solids capture in a RAS wastewater treatment system will depend on the intended fate of the treated effluent.}, journal={AQUACULTURAL ENGINEERING}, author={Guerdat, Todd C. and Losordo, Thomas M. and DeLong, Dennis P. and Jones, Richard D.}, year={2013}, month={May}, pages={1–8} }
 @article{guerdat_losordo_classen_osborne_delong_2011, title={Evaluating the effects of organic carbon on biological filtration performance in a large scale recirculating aquaculture system}, volume={44}, ISSN={["1873-5614"]}, DOI={10.1016/j.aquaeng.2010.10.002}, abstractNote={Studies evaluating the impact of organic carbon on biological filters at the large scale for aquaculture production are lacking. Understanding the performance characteristics of different biofilters under actual production conditions will be the only means by which recirculating system designers may properly select and size biological filters for commercial production use. Previous studies have determined the impact of organic carbon on biofilter performance at the small lab scale often using artificial waste nutrients in the evaluation. Evaluations under actual production conditions using real wastewater produce vastly different results than previous lab scale studies using artificial nutrients. As such, this study is a preliminary step in evaluating the impact of organic carbon on three different commercially available biological filters at the large scale under actual recirculating aquaculture production conditions. The study was conducted at the North Carolina State University Fish Barn—a commercial scale research and demonstration recirculating aquaculture facility operated by the Biological and Agricultural Engineering department. The study was based on a 60 m3 Tilapia system with average daily feed rates of 45 kg using a 40% protein feed and an average biomass of 6750 kg. The system was dosed with sucrose (C12H22O11) to increase the concentration of biodegradable organic carbon in the system. The effect of elevated organic carbon concentrations on total ammoniacal nitrogen (TAN) removal rates was evaluated and determined based on biofilter media volume. Variability increased substantially in the volumetric TAN removal rate (VTR) for all three filters. VTR for all three filter types was reduced by approximately 50% as compared to normal production conditions. The results demonstrate the importance of controlling the concentration of biologically available organic carbon in a recirculating aquaculture system.}, number={1}, journal={AQUACULTURAL ENGINEERING}, author={Guerdat, Todd C. and Losordo, Thomas M. and Classen, John J. and Osborne, Jason A. and DeLong, Dennis}, year={2011}, month={Jan}, pages={10–18} }
 @article{guerdat_losordo_classen_osborne_delong_2010, title={An evaluation of commercially available biological filters for recirculating aquaculture systems}, volume={42}, ISSN={["0144-8609"]}, DOI={10.1016/j.aquaeng.2009.10.002}, abstractNote={Three different commercially available biological filters were evaluated in triplicate on a 60 m3 tank-based Tilapia system under commercial warmwater growout conditions. The study was performed at the North Carolina State University Fish Barn—a commercial scale research and demonstration recirculating aquaculture facility operated by the department of Biological and Agricultural Engineering. Total ammoniacal nitrogen (TAN) removal rates were determined for the three types of biofilters for a range of concentrations ranging from 0.13 to 1.20 g TAN m−3. TAN concentrations were varied by feed rates and ammonium chloride additions, and limited by fish feeding response. Maximum feed rates were 65 kg feed d−1 using a 40% protein diet at a maximum biomass of 5500 kg. Average observed TAN removal rates (in g TAN m−3 of unexpanded media d−1 ± standard deviation) for the three filters were 267 ± 123, 586 ± 284, and 667 ± 344 for the moving bed bioreactor, floating bead filter, and fluidized sand filter, respectively. These results are considerably lower than results previously published at the laboratory scale using artificial waste nutrients. This study highlights the need for future biofilter evaluations at the commercial scale using real aquaculture waste nutrients.}, number={1}, journal={AQUACULTURAL ENGINEERING}, author={Guerdat, Todd C. and Losordo, Thomas M. and Classen, John J. and Osborne, Jason A. and DeLong, Dennis P.}, year={2010}, month={Jan}, pages={38–49} }
 @article{li_willits_browdy_timmons_losordo_2009, title={Thermal modeling of greenhouse aquaculture raceway systems}, volume={41}, ISSN={["1873-5614"]}, DOI={10.1016/j.aquaeng.2009.04.002}, abstractNote={A mechanistic model was developed to describe the thermal behavior of an indoor raceway system with an inflated double polyethylene cover. The model describes the heat balances of the two covers, the inside air, the water in the raceway and the soil beneath the raceway. On-site measurements were made with an experimental system at the Waddell Mariculture Center in South Carolina. The collected data were used to calibrate the model. Comparison of the predictions with observations showed that the average absolute errors of air temperature and water temperature were 1.4 and 0.5 °C, respectively and was 8% for the relative humidity. The accuracies are regarded as sufficient for the model to be useful for more general application. Model simulations were used to investigate the effects of the greenhouse on the air and water temperatures, to examine the heat fluxes and to calculate the heat consumption and costs at four different climatic locations. The results suggest that under the mild weather conditions in January near Charleston, SC where the daily mean temperature is 7.6 °C and solar radiation is 121 W m−2, the inside air temperature increases by 5.6 °C and water temperature increases by 9.7 °C on average for the system with the 0.85 m deep raceway covering 70% of the greenhouse floor. An examination of the heat fluxes suggests that thermal radiation is a major mechanism of heat loss for the greenhouse covers and the water surface. Convection from the water surface is also a significant mechanism for latent and sensible heat loss from the raceway. Reducing these heat flows will help conserve and utilize energy. The yearly heating requirements to keep the water temperature at 28 °C for the experimental system were estimated to be 870, 520, 274 and 221 kWh per square meter of raceway for Syracuse, NY, Roanoke, VA, Charleston, SC and Baton Rouge, LA, respectively. The model was deemed to be a useful tool for exploring the performance of greenhouse raceway systems under different scenarios, such as different cover materials, sizes and climates.}, number={1}, journal={AQUACULTURAL ENGINEERING}, author={Li, Shuhai and Willits, Daniel H. and Browdy, Craig L. and Timmons, Michael B. and Losordo, Thomas M.}, year={2009}, month={Jul}, pages={1–13} }
 @article{hamlin_michaels_beaulaton_graham_dutt_steinbach_losordo_schrader_main_2008, title={Comparing denitrification rates and carbon sources in commercial scale upflow denitrification biological filters in aquaculture}, volume={38}, DOI={10.1016/j.aquaeng.2007.11.003}, abstractNote={Aerobic biological filtration systems employing nitrifying bacteria to remediate excess ammonia and nitrite concentrations are common components of recirculating aquaculture systems (RAS). However, significant water exchange may still be necessary to reduce nitrate concentrations to acceptable levels unless denitrification systems are included in the RAS design. This study evaluated the design of a full scale denitrification reactor in a commercial culture RAS application. Four carbon sources were evaluated including methanol, acetic acid, molasses and Cerelose™, a hydrolyzed starch, to determine their applicability under commercial culture conditions and to determine if any of these carbon sources encouraged the production of two common “off-flavor” compounds, 2-methyisoborneol (MIB) or geosmin. The denitrification design consisted of a 1.89 m3 covered conical bottom polyethylene tank containing 1.0 m3 media through which water up-flowed at a rate of 10 lpm. A commercial aquaculture system housing 6 metric tonnes of Siberian sturgeon was used to generate nitrate through nitrification in a moving bed biological filter. All four carbon sources were able to effectively reduce nitrate to near zero concentrations from influent concentrations ranging from 11 to 57 mg/l NO3–N, and the maximum daily denitrification rate was 670–680 g nitrogen removed/m3 media/day, regardless of the carbon source. Although nitrite production was not a problem once the reactors achieved a constant effluent nitrate, ammonia production was a significant problem for units fed molasses and to a less extent Cerelose™. Maximum measured ammonia concentrations in the reactor effluents for methanol, vinegar, Cerelose™ and molasses were 1.62 ± 0.10, 2.83 ± 0.17, 4.55 ± 0.45 and 5.25 ± 1.26 mg/l NH3–N, respectively. Turbidity production was significantly increased in reactors fed molasses and to a less extent Cerelose™. Concentrations of geosmin and MIB were not significantly increased in any of the denitrification reactors, regardless of carbon source. Because of its very low cost compared to the other sources tested, molasses may be an attractive carbon source for denitrification if issues of ammonia production, turbidity and foaming can be resolved.}, number={2}, journal={Aquacultural Engineering}, author={Hamlin, H. J. and MichaelS, J. T. and Beaulaton, C. M. and Graham, W. F. and Dutt, W. and Steinbach, P. and Losordo, T. M. and Schrader, K. K. and Main, K. L.}, year={2008}, pages={79–92} }
 @article{carroll_watanabe_losordo_2005, title={Pilot production of hatchery-reared summer flounder Paralichthys dentatus in a marine recirculating aquaculture system: The effects of ration level on growth, feed conversion, and survival}, volume={36}, DOI={10.1111/j.1749-7345.2005.tb00138.x}, abstractNote={Pilot-scale trials were conducted to evaluate growout performance of hatchery-reared summer flounder fingerlings in a state-of-the-art recirculating aquaculture system (RAS). The outdoor RAS consisted of four 4.57-m dia × 0.69-m deep (vol. =11.3 m3) covered, insulated tanks and associated water treatment components. Fingerlings (85.1 g mean initial weight) supplied by a commercial hatchery were stocked into two tanks at a density of 1,014 fish/tank (7.63 kg/m3). Fish were fed an extruded dry floating diet consisting of 50% protein and 12% lipid. The temperature was maintained between 20 C and 23 C and the salinity was 34 ppt. Under these conditions, growth, growth variation (CVwt), feed utilization, and survival of fish fed to 100% and 82% of a satiation rate were compared. 
 
 
 
Due to clear changes in growth patterns during the study, data was analyzed in three phases. During phase 1 (d 1–d 196), fish showed rapid growth, reaching a mean weight of 288 g ± 105 and 316 g ± 102, with a CVwt of 0.36 and 0.32 and FCR's of 1.38 and 1.36 in the subsatiation and satiation groups, respectively. During phase 2 (d 196–d 454), fish displayed slower growth reaching mean weights of 392 g ± 144 and 436 g ± 121, with a CVwt of 0.37 and 0.28, and increasing FCR's of 3.45 and 3.12 in the subsatiation and satiation groups, respectively. During phase 3 (d 454–d 614), fish showed little growth reaching mean weights of 399 g ± 153 and 440 g ± 129, with a CVwt of 0.38 and 0.29 in the subsatiation and satiation groups, respectively. Over the entire growout period (d 1–d 614), feed conversion ratios were 2.39 and 2.37 and survival was 75% and 81 % in the subsatiation and satiation treatments, respectively. The maximum biomass density reached during the study was 32.3 kg/m3. 
 
 
 
The satiation feed rate was superior to the 82% satiation rate, since it maximized growth rates, with no effect on FCR. The higher CVwt in the subsatiation group suggests increased competition for a restricted ration led to a slower growth with more growth variation. The decrease in growth in phases 2 and 3 was probably related to a high percentage of slower growing male fish in the population and the onset of sexual maturity. 
 
 
 
This study demonstrated that under commercial scale conditions, summer flounder can be successfully grown to a marketable size in a recirculating aquaculture system. Based on these results, it is recommended that a farmer feed at a satiation rate to minimize growout time. More research is needed to maintain high growth rates through marketable sizes through all-female production and/or inhibition of sexual maturity.}, number={1}, journal={Journal of the World Aquaculture Society}, author={Carroll, P. M. and Watanabe, W. O. and Losordo, T. M.}, year={2005}, pages={120–128} }
 @article{saliling_westerman_losordo_2007, title={Wood chips and wheat straw as alternative biofilter media for denitrification reactors treating aquaculture and other wastewaters with high nitrate concentrations}, volume={37}, ISSN={["1873-5614"]}, DOI={10.1016/j.aquaeng.2007.06.003}, abstractNote={This study evaluated wood chips and wheat straw as inexpensive and readily available alternatives to more expensive plastic media for denitrification processes in treating aquaculture wastewaters or other high nitrate waters. Nine 3.8-L laboratory scale reactors (40 cm packed height × 10 cm diameter) were used to compare the performance of wood chips, wheat straw, and Kaldnes plastic media in the removal of nitrate from synthetic aquaculture wastewater. These upflow bioreactors were loaded at a constant flow rate and three influent NO3–N concentrations of 50, 120, and 200 mg/L each for at least 4 weeks, in sequence. These experiments showed that both wood chips and wheat straw produced comparable denitrification rates to the Kaldnes plastic media. As much as 99% of nitrate was removed from the wastewater of 200 mg NO3–N/L influent concentration. Pseudo-steady state denitrification rates for 200 mg NO3–N/L influent concentrations averaged (1360 ± 40) g N/(m3 d) for wood chips, (1360 ± 80) g N/(m3 d) for wheat straw, and (1330 ± 70) g N/(m3 d) for Kaldnes media. These values were not the maximum potential of the reactors as nitrate profiles up through the reactors indicated that nitrate reductions in the lower half of the reactors were more than double the averages for the whole reactor. COD consumption per unit of NO3–N removed was highest with the Kaldnes media (3.41–3.95) compared to wood chips (3.34–3.64) and wheat straw (3.26–3.46). Effluent ammonia concentrations were near zero while nitrites were around 2.0 mg NO2–N/L for all reactor types and loading rates. During the denitrification process, alkalinity and pH increased while the oxidation–reduction potential decreased with nitrate removal. Wood chips and wheat straw lost 16.2% and 37.7% of their masses, respectively, during the 140-day experiment. There were signs of physical degradation that included discoloration and structural transformation. The carbon to nitrogen ratio of the media also decreased. Both wood chips and wheat straw can be used as filter media for biological denitrification, but time limitations for the life of both materials must be considered.}, number={3}, journal={AQUACULTURAL ENGINEERING}, author={Saliling, Willie Jones B. and Westerman, Philip W. and Losordo, Thomas M.}, year={2007}, month={Nov}, pages={222–233} }
 @article{delong_losordo_2006, title={A comparison of alternative designs and technologies in recirculating aquaculture}, ISBN={0978094301}, journal={Aquaculture Canada 2004 : ?b proceedings of contributed papers, Canadian Freshwater Aquaculture Symposium, Que?bec City, Que?bec, October 17-24, 2004}, publisher={St. Andrews, N.B. :  Aquaculture Association of Canada}, author={DeLong, D. P. and Losordo, T. M.}, editor={E?. Gilbert, D. Stechey and Struthers, M.Editors}, year={2006} }
 @article{copeland_watanabe_carroll_wheatley_losordo_2003, title={Growth and feed utilization of captive wild black sea bass Centropristis striata at four different densities in a recirculating tank system}, volume={34}, ISSN={["0893-8849"]}, DOI={10.1111/j.1749-7345.2003.tb00068.x}, abstractNote={AbstractA study to determine the effects of four stocking densities on growth and feed utilization of wild‐caught black sea bass Centropristis striata was conducted in a pilot‐scale recirculating tank system. The outdoor system consisted of 12 insulated fiberglass tanks (dia. = 1.85 m; vol. = 2.17 m3) supported by biological filters, UV sterilizers, and heat pumps. Subadults (N= 525; ×± SD = 249 ± 16.8 g) were stocked at densities of 4.6 fish/m3 (1.18 kg/m3), 16 fish/ m3 (3.91 kg/m3), 25.3 fish/m3 (6.83 kg/m3), and 36 fish/m3 (7.95 kg1m3), with three replicate tanks per treatment. Fish were grown under 35 ppt salinity, 21‐25 C, and under ambient photoperiod conditions. A commercial flounder diet containing 50% protein and 12% lipid was hand‐fed twice daily to satiation for 201 d.Mean (range) total ammonia‐nitrogen, 0.61 (0‐2.1) mg/L, nitrite‐nitrogen, 0.77 (0.04‐3.6) mg/L, and nitrate‐nitrogen 40.1 (0‐306) mg/L were significantly higher (P < 0.0001) in the 25.3 and 36 fish/m3 treatments than in the 4.6 and 16 fish/m3 treatments [0.19 (0.05‐0.5), 0.1 (0.24‐0.63), and 11.9 (1.3‐82.2) mg/L, respectively]. However, there were no significant differences (P > 0.05) in growth (RGR = 196.8‐243.1%; DWG = 2.55‐2.83 g/d; and SGR = 0.55‐0.61%/d), coefficient of variation of body weight (CwtV., = 0.24‐0.25), condition factor (K = 2.2‐2.4), feed consumption (FC = 1.45‐1.65%/d), and feed conversion ratio (FCR = 1.45‐1.52) among stocking densities. Final biomass densities on day 201 reached 3.48, 12.0, 21.1, and 27.2 kg/m3 at stocking densities of 4.6, 16, 25.3, and 36 fish/m3, respectively. Survival (83.8‐99.1%) did not differ among treatments. Apparent net protein retention (ANPR) was significantly higher (P < 0.005) for fish stocked at the lower densities of 4.6 and 16 fish/m3 (22.5‐23.7%) than for those stocked at 25.3 and 36 fish/m3 (21‐20.1%). There were no significant differences (P > 0.05) in apparent net energy retention (ANER = 55.9‐59.1 %) among stocking densities. Final whole body protein (15.3‐16.3%) and lipid (23.1‐26.4%) levels did not differ significantly (P > 0.05) among treatments.The results demonstrated that growth, survival, and feed utilization were not impaired under stocking densities ranging from 4.6‐36 fish/m3 (3.48‐27.2 kg/m3), despite a slight reduction in water quality at the higher densities. In addition, growth variation and final whole body protein and lipid levels were not influenced by these densities. The results suggest that black sea bass are tolerant of crowding and moderate variations in water quality during intensive culture in recirculating tank systems and that higher stocking densities are possible.}, number={3}, journal={JOURNAL OF THE WORLD AQUACULTURE SOCIETY}, author={Copeland, KA and Watanabe, WO and Carroll, PM and Wheatley, KS and Losordo, TM}, year={2003}, month={Sep}, pages={300–307} }
 @article{watanabe_losordo_fitzsimmons_hanley_2002, title={Tilapia production systems in the Americas: Technological advances, trends, and challenges}, volume={10}, ISSN={["1064-1262"]}, DOI={10.1080/20026491051758}, abstractNote={Tilapia is the common name applied to three genera of fish in the family Cichlidae: Oreochromis, Sarotherodon, and Tilapia. The species that are most important for aquaculture are in the genus Oreochromis, including the Nile tilapia, O. niloticus, the Mozambique tilapia, O. mossambicus, the blue tilapia, O. aureus, and O. urolepis hornorum. Fish farmers are now growing many strains of these parent species along with many hybrid strains. Native to Africa and the Middle East, these species have become the second most common farm raised food fish in the world. In the 1960s and 1970s tilapia culture was aimed at the production of food for local consumption, utilizing primarily extensive or semiintensive culture methods with minimal inputs of fertilizer or feeds. However, tilapia culture has expanded rapidly during the last decade as a result of technological advances associated with the intensification of culture practices. These include the development of new strains and hybrids, monosex male culture, formulated diets, a variety of semiintensive and intensive culture systems (e.g., ponds, cages, tanks, and raceways) and the utilization of greenhouses, geothermal, or industrial waste heat and advanced water treatment methods. Marketing programs have also nurtured a growing demand for tilapia in domestic and international markets. Annual worldwide production of cultured tilapia was less than 200,000 metric tons (mt) in 1984 and increased to 1,100,000 mt in 1999. In the Americas, the increased production of farmed tilapia is due in large part to their adaptability to a diverse array of production systems. These include subsistence level, extensive pond culture in the Eastern Caribbean, integrated animal-fish culture in Guatemala and Panama, semiintensive pond culture in Honduras, intensive pond culture in Colombia, Costa-Rica and Jamaica, semiintensive cage culture in several countries, intensive flowthrough tank and raceway culture in the U.S., and a variety of highly intensive indoor recirculating tank culture in the U.S. In addition, there is increasing production of tilapia in shrimp ponds in Ecuador to ameliorate shrimp disease problems. In this article, representatives of various systems are compared with respect to technological approaches and constraints. Poor management of tilapia genetic resources is causing a loss of productivity, and research in genetics and selective breeding will be needed to improve production efficiency, fillet yields, and environmental tolerance. Continuing nutritional studies will also be needed to increase efficiency and profitability. With intensification, infectious diseases have become more serious, and fish health management through biosecurity procedures, environmental manipulation, reduction of stress, nutrition, genetics, and the use of prophylactic therapeutics will be essential. Increasing waste production will require novel methods for integrating tilapia culture with the production of other valuable crops to maximize nutrient recovery and minimize pollution. Market development and quality control will be critical to ensure market growth.}, number={3-4}, journal={REVIEWS IN FISHERIES SCIENCE}, author={Watanabe, WO and Losordo, TM and Fitzsimmons, K and Hanley, F}, year={2002}, pages={465–498} }
 @article{losordo_hobbs_delong_2000, title={The design and operational characteristics of the CP&L/EPRI fish barn: a demonstration of recirculating aquaculture technology}, volume={22}, ISSN={["0144-8609"]}, DOI={10.1016/S0144-8609(00)00029-7}, abstractNote={The Carolina Power & Light Company, in conjunction with the Electric Power Research Institute of Palo Alto, California has developed a commercial fish production demonstration utilizing water reuse technology developed at the North Carolina State University Fish Barn. The fish production system is housed in a 39.6 m long by 9.75 m wide barn structure located on the campus of North Carolina State University in Raleigh, NC. Fish production activities began in the spring of 1998. The facility is designed to produce 45 tonnes of fish annually, with the first crop being tilapia. The project is being operated as a public demonstration of this technology, with biological, engineering and economic data being collected by research and extension personnel at North Carolina State University. This paper outlines the design of the recirculating system technology used to recycle water through the main fish production tanks.}, number={1-2}, journal={AQUACULTURAL ENGINEERING}, author={Losordo, TM and Hobbs, AO and DeLong, DP}, year={2000}, month={May}, pages={3–16} }
 @article{losordo_hobbs_2000, title={Using computer spreadsheets for water flow and biofilter sizing in recirculating aquaculture production systems}, volume={23}, ISSN={["0144-8609"]}, DOI={10.1016/S0144-8609(00)00048-0}, abstractNote={North Carolina State University has been active in the development, evaluation and demonstration of recirculating aquaculture technology since 1989. In the process, numerous engineering and economic spreadsheets (worksheets) have been developed to assist in the design and analysis of these systems. The spreadsheet described in this paper is based on a set of mass balance equations developed and described by Losordo and Westers (Vol. 27, 1994 pp. 9–60) to estimate the carrying capacity and required flow rates of recirculating aquaculture production systems. This spreadsheet can be used to estimate the recycle flowrate that is required to maintain user specified water quality conditions for a given feed input rate and water treatment system configuration. These water quality conditions include suspended solids, total ammonia-nitrogen, and dissolved oxygen concentration. The spreadsheet also provides an estimate of the new water required by the system to maintain a user specified nitrate-nitrogen concentration. In addition, the spreadsheet provides an estimate of the required biofilter volume and cross-sectional (top) surface area for the given biofilter shape, depth and specific surface area of the biofilter media. The mass balance equations used in this spreadsheet are based upon waste metabolites generated and oxygen consumed by daily inputs of feed into a system.}, number={1-3}, journal={AQUACULTURAL ENGINEERING}, author={Losordo, TM and Hobbs, AO}, year={2000}, month={Sep}, pages={95–102} }
 @article{lewbart_stoskopf_losordo_geyer_owen_smith_law_altier_1999, title={Safety and efficacy of the Environmental Products Group Masterflow Aquarium Management System with Aegis Microbe Shield (TM)}, volume={19}, ISSN={["0144-8609"]}, DOI={10.1016/S0144-8609(98)00043-0}, abstractNote={This study investigated the safety and efficacy of the EPG Masterflow Aquarium Management System with Aegis Microbe Shield™ (EPG-MAMS). Four different species of fish were used in the study. Ten fish of each species were placed in 75 l aquariums containing the EPG filter media, a commercially available filter media (Whisper®) and an aquarium with no filter material. At the end of the 45 day trial three fish from each tank were sacrificed and preserved in formalin for histopathology. Water quality parameters were routinely monitored. The EPG filter media was compared with the Whisper® filter media for efficacy against Aeromonas salmonicida using a shaker flask microbiological assay. The EPG filter proved to be clinically and histopathologically safe and reduced to some degree the number of A. salmonicida suspended in water in an in vitro study.}, number={2}, journal={AQUACULTURAL ENGINEERING}, author={Lewbart, GA and Stoskopf, MK and Losordo, T and Geyer, J and Owen, J and Smith, DW and Law, M and Altier, C}, year={1999}, month={Jan}, pages={93–98} }
 @article{twarowska_westerman_losordo_1997, title={Water treatment and waste characterization evaluation of an intensive recirculating fish production system}, volume={16}, DOI={10.1016/S0144-8609(96)01022-9}, abstractNote={A combination of two different technologies used for fish production was evaluated at the North Carolina State University (NCSU) F̀ish Barn facility. The combined system included the ECOFISH∗ tank, developed at the Norwegian Hydrotechnical Laboratory (NHL) at SINTEF (Trondheim, Norway) and water treatment and recycle technology designed at NCSU. Approximately 2170 fingerling tilapia (Oreochromis niloticus, Oreochromis niloticus × Oreochromis aureus) were grown from 3.6 to 507 g in 177 days in a 20 m3 four-zone tank. The system design included patented particle traps at the bottom of each zone to remove feed waste and excrement, sludge collectors where the removed particles settled, a rotating screen filter for suspended solids removal, a high-rate linear-path trickling biological filter for nitrification, and two down-flow columns for oxygen injection. The measured suspended solids level in the tank zones were usually less than 7.5 mg l −1. Based on six efficiency tests with a mean total ammonia nitrogen (TAN) concentration in the culture tank of 0.62 mg l −1, the biofilter removed approximately 65% on a single pass through the filter, with an average removal rate per unit of filter surface area of 0.33 g TAN m −2 day −1. Sampling every 4 h over a 24-h period showed variability in concentrations and TAN removal rates by the biofilter. Six efficiency tests on the sludge collectors and the screen filter showed 80% and 41% suspended solids removal efficiency, respectively, based on the influent and effluent concentrations. On a daily basis, the sludge collectors and the screen filter each removed about 18% of feed volatile solids input, respectively, based on three 24-h periods studied. Fresh water use averaged approximately 1500 l day −1, which was about 7% of the system volume.}, number={3}, journal={Aquacultural Engineering}, author={Twarowska, J. G. and Westerman, P. W. and Losordo, T. M.}, year={1997}, pages={133–147} }
 @article{losordo_westerman_1994, title={An analysis of biological, economic, and engineering factors affecting the cost of fish production in recirculating aquaculture systems}, volume={25}, DOI={10.1111/j.1749-7345.1994.tb00181.x}, abstractNote={AbstractAquaculture production in recirculating systems has been the focus of research and development efforts for decades. Although considerable resources have been expended on these systems in the private sector, there is a scarcity of data on the economic or engineering performance of commercial scale recirculating production systems. This paper presents the results of a computer simulation of tilapia production in a small recirculating production system. Much of the performance data has been developed at a demonstration facility at North Carolina State University. Given the assumptions of the base case simulation, the cost of producing a kilogram of tilapia in the recirculating system described is estimated to be $2.79 ($1.27/lb). The results of a model sensitivity analysis indicate that while improvements in the performance efficiency of system components did not greatly affect fish production costs, reductions in feed costs and improvements in the feed conversion ratio caused the greatest reduction of production cost of all of the operational variables investigated. The analysis further indicates that the greatest gains to be realized in improving profitability are those associated with increasing the productive capacity or decreasing the investment cost of a recirculating fish production system.}, number={2}, journal={Journal of the World Aquaculture Society}, author={Losordo, T. M. and Westerman, P. W.}, year={1994}, pages={193} }
 @article{losordo_easley_westerman_1989, title={The preliminary results of a feasibility study of fish production in recirculating aquaculture systems}, number={89-7557}, journal={Paper (American Society of Agricultural Engineers)}, author={Losordo, T. M. and Easley, J. E. and Westerman, P. W.}, year={1989}, pages={18} }