Sponsoring Institution
National Institute of Food and Agriculture
Project Status
Funding Source
Reporting Frequency
Accession No.
Grant No.
Project No.
Proposal No.
Multistate No.
Program Code
Project Start Date
Oct 1, 2007
Project End Date
Sep 30, 2008
Grant Year
Project Director
Flick, G. J.
Recipient Organization
Performing Department
Non Technical Summary
America is by far the largest importer of shrimp in the world, averaging more than a billion pounds annually. Domestic production of shrimp is low, resulting in a $3 billion federal trade deficit in shrimp products. The purpose of this study is to discover economically viable production methods for marine shrimp in a controlled environment, hence developing a significant aquaculture industry in Virginia, providing for jobs and a safe, healthy, secure food supply.
Animal Health Component
Research Effort Categories

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
Goals / Objectives
The over-riding objective of this research is to find ways to reduce cost, increase production efficiencies and increase market value of marine shrimp raised in a controlled environment facility to develop a viable shrimp aquaculture industry in rural (non-costal) locations. Five specific objectives include the following: 1) Evaluate the operation and efficiency of air diffusers for use in the production tanks; 2) Monitor the water quality in the production tanks to ensure adequate mixing and oxygen distribution from the diffusers and adequate water quality conditions for the production of the shrimp under variable stocking densities; 3) Evaluate the optimum operating conditions for treating aquacultural effluent from a tilapia farm using biological, suspended growth processes. The bioflocs generated in the systems will then be fed to shrimp as a way to mitigate commercial feed requirements. Three major bioreactor operating conditions will be evaluated and compared including a) aerobic treatment without carbon supplementation (CS), b) aerobic treatment with CS, and c) aerobic/anaerobic treatment with CS. Shrimp feeding/nutrition trials will investigate replacing commercial feed protein with biofloc proteins. 4) Determine the effect of the addition of substrate material within production tanks on shrimp growth rates and survival when stocked at high densities within the system; and 5) Investigate methods of transporting live shrimp to distant markets to allow the product to be sold in high-value markets and hence obtain the price required to make the venture economically viable.
Project Methods
To investigate the efficiency of various air diffusers to provide the necessary mixing and dissolved oxygen concentrations. various diffusers and diffuser configurations will be evaluated prior to installation of the final diffuser system at the site. The diffusers being evaluated will include, but may not be limited to, fine bubble diffusers and traditional air-line diffusers. Air flow to the diffuser and resulting dissolved oxygen concentration in the tank will be measured to determine the efficiency of oxygen transfer. Water quality monitoring will determine the efficiency of mixing within the tank. The goal of this investigation is to obtain an efficient and effective diffuser for the system without producing additional issues such as foaming. For the tilapia effluent studies, three pilot-scale, sequencing batch reactors (SBRs) will be used in this study to investigate how to best treat tilapia effluent. These 1,350 gallon SBRs (CA-15d model, Cromaglass Corporation, Williamsport, PA) will be installed onsite at Blue Ridge Aquaculture (BRA), and operated aerobically or erobically/anaerobically. Aerobic treatment of the effluent with and without carbon (e.g. sugar, molasses, and/or corn gluten) supplementation will be evaluated, as well as aerobic/anaerobic treatment with carbon supplementation. Input equirements, treatment efficiencies and costs will be compared. As part of a separate study, the biomass produced will be used as a supplemental shrimp feed. Therefore, biomass production and characterization are also an integral and important part of this study. Feeding trials will investigate replacing commercial feed protein with biofloc proteins. Twelve 50 gallon life support systems will be used to test various feeding regimes and their effects of shrimp performance and health. For example, four treatments in triplicate could include the following: 100% commercial feed (CF), 80% CF with 20% Biofloc (F), 60% CF with 40% F, and 40% CF with 60% floc. After results are collected and analyzed, appropriate adjustments will be made to determine the optimum feeding regime. To optimize substrate usage in the grow out tanks, nine commercial-scale tanks (12.2 m x 3.7m x 1.2 m deep), each with an independent water treatment system, will be employed. The nine systems allow for three treatments with three replicates for each experiment. Treatments will consist of three different densities of horizontal substrate or "shelving". Fifty shrimp will be randomly sampled from each tank each week. The 50 shrimp will be weighed as a group and examined for any signs of exoskeletal damage. Water quality data will be analyzed using descriptive statistics. ANOVA will be used to determine if variations in growth and survival rates in the various system configurations are statistically significant. Two methods of marketing live shrimp will be investigated including live haul shipment using live haul tanks on trucks and dry shipment containers including wood shavings, wood wool, or sawdust that has been soaked in oxygen-saturated water. Product will be shipped and evaluated on the receiving end.

Progress 10/01/07 to 09/30/08

OUTPUTS: Biofloc experiments were conducted using bioreactors to treat tilapia effluent with and without carbon supplementation. Additionally, biofloc generated in bioreactors using sugar and tilapia wastewater was used as a component of three formulated, nutritionally-complete shrimp diets. Three diets containing biofloc were compared against two control diets which did not include bioflocs. The five diets were compared in growth and survival trials. This work has been presented at two conferences, Aquaculture America (Orlando, Florida, February 2008) and the International Recirculating Aquaculture Conference (Roanoke, Virginia, July 2008). Water quality data were collected at Virginia Shrimp Farms (VSF) to assure adequate water quality conditions and mixing for the production of shrimp under variable stocking densities. To analyze the operation and efficiency of the treatment devices on the shrimp grow out system at VSF, sample ports were placed to capture the influent and effluent from each step of the treatment process. Four rounds of sampling were completed between May 21 and July 14, 2008. The analyses included measurements of pH, temperature, salinity, dissolved oxygen, ammonia, nitrite, nitrate, orthophosphate, total organic carbon, total suspended solids, and alkalinity. Through this monitoring, mixing conditions in the production tanks were evaluated by performing depth sampling at multiple locations within the same tank. Analysis of the data shows that the mixing within the tanks is adequate as evidenced by nearly identical water quality measurements obtained at different depths and locations within a given tank. A horizontal substrate with either 12, 18 or 24 vertical inches between layers was placed in each shrimp growout tank at VSF. Each of the nine commercial growout tanks at VSF received one of the substrate treatments, resulting in 3 replicates. Twice weekly for 25 weeks, shrimp were netted by hand, counted and weighted. Using this data, growth rate for each tank and each substrate configuration was plotted. Shipping studies were conducted to determine the survival rate of Litopenaeus vannamei when shipped either dry or in water. For the dry shipping study, shrimp were acclimated from the growout temperature of 30C to shipping temperature of 9, 12 or 15C at three different acclimation rates. Following acclimation, shrimp were placed in a box lined with a plastic bag which contained wet excellsor and the bag was filled with oxygen and then sealed. The boxes where stored in incubators maintained at 9, 12 or 15C and opened after 24 hrs to determine survival rates. In the wet shipping studies, shrimp were acclimated from 30 to 21, 19 or 17C in a period of two to four hours and then placed in water of the same temperature and trucked from Virginia to New York City, New York, where survival was noted (approximately 20 hours in transit before unloading). PARTICIPANTS: Dr. George Flick provided oversight for the project and directed the live shrimp shipping studies. Dr. Lori Marsh conducted the substrate research. Dr. David Kuhn conducted the biofloc research. Dr. Gregory Boardman provided assistance for water quality assessment and treatment issues. Mr. Todd Blacher was responsible for the day-to-day management of the shrimp facility. Dr. Stephen Smith provided veterinary medical advice as needed. Amy Cheatham and Susan Mirlohi collected water samples and ran water quality analyses. Dianne Bourne and Sheila Holliman performed microbiological testing. Partner organizations and collaborators included Zeigler Brothers, Inc., MeriCal, Blue Ridge Aquaculture, Virginia Shrimp Farms, and Texas A&M University. Training or professional development: Two International conferences were conducted in July, 2008--The Aquaculture Engineering Society forum and the International Conference on Recirculating Aquaculture. The two programs brought international experts together to discuss recent advances in the scientific and technological aspects of recirculating aquaculture. Some of the information presented at both programs was obtained from research activities that occurred in this project. Attendees included scientist, regulators, and entrepreneurs, having substantial financial investments in recirculating aquaculture systems. TARGET AUDIENCES: The target audience for this work is anyone currently operating or considering starting an indoor recirculating aquaculture venture. In addition to specific research carried out with commercial scale shrimp production systems, a video describing indoor recirculating aquaculture was produced and distributed at the Boston Seafood Show. PROJECT MODIFICATIONS: Not relevant to this project.

Bioflocs were generated in sequencing batch reactors (SBRs) using wastewater discharged from an indoor recirculating aquaculture facility producing tilapia. Treatment efficiencies and biofloc production were enhanced when carbon supplementation was used compared to no carbon supplementation. Biofloc yield averaged 0.7kg of biofloc per 1 kg of sugar and removal of reduced nitrogen and dissolved organic matter exceeded 85%. The resulting biofloc had an average crude protein content of 49 (g/100g dry matter) compared to a crude protein content of 14(g/100g dry matter) for untreated solids removed by drum filter from the same wastewater stream. Five shrimp diets were formulated with equivalent levels of crude protein (35.0%), crude fat (7.5%), crude fiber (3.25%), calcium (2.75%), magnesium (1.00%), phosphorus (1.90%), potassium (1.30%), and sodium (0.90%). Two of the diets contained no bioflocs, in two of the diets, soybean isolate was replaced by biofloc at inclusion levels of 7.8 and 15.6% biofloc; in one diet, fishmeal was replaced with bioflocs at 7.8% and fish oil was added at 0.50%. Final survival rates in the growth trials were not statistically different for the various diets. However, diets that contained bioflocs resulted in significantly increased growth rates compared to diets without bioflocs. However, there were no significant differences in growth rates within the three diets that contained bioflocs or within the two diets that did not contain bioflocs. The results of this study are encouraging. Significant enhancement of shrimp growth was observed for biofloc diets over the control diets, irrespective of biofloc inclusion levels or replacement of soybean versus fishmeal protein. This project demonstrates the feasibility of treating one aquaculture wastewater while producing a quality ingredient for shrimp feed--a novel approach that could increase economic and environmental sustainability of clear water recirculating aquaculture systems. Several organizations expressed an interest in expanding the study and potentially commercializing the process. A multi-disciplinary, multi-organization research group, including two universities, three commercial aquaculture firms, and a feed manufacturer has formed. This public/private partnership is expanding the scientific and technological activities outlined in this research activity. There was no discernible difference in shrimp growth rate as a function of substrate spacing in the growout tanks. There were no significant differences between the three acclimation rates or the three storage temperatures in the dry shipping study. Survival was unacceptably low for all treatments (below 30%), indicating that more study is needed to find an acceptable dry shipping method. Live shipping trials had survival rates from 87 to 96%. There was a trend in the data showing greater survival with a shorter acclimation period (2 versus 4 hours) and when shipping occurs at cooler temperatures (17 versus 21 C). The ability to ship live animals with high survival rates (above 90%) opens up a high-value market for shrimp produced in recirculating aquaculture systems.


  • Kuhn, D.D., G.D. Boardman, A. Lawrence, L. Marsh, G.J. Flick, Jr. 2008. Use of Bioflocs as an Ingredient in Shrimp Feed. In: Proceedings of the 7th International Conference on Recirculating Aquaculture. July 25-27, 2008, Roanoke, Virginia. pp. 74-78.
  • Marsh, L., Flick, G., Boardman, G., Kuhn, D., and Smith, S. 2008. Collaborative research toward a sustainable shrimp aquaculture industry in Virginia. In: Proceedings of the 7th International Conference on Recirculating Aquaculture. July 25-27, 2008, Roanoke, Virginia. pg. 518.
  • Kuhn, D.D., G.D. Boardman, S.R. Craig, E. McLean, and G.J. Flick, Jr. 2008. Integrating tilapia effluent with shrimp culture to enhance aquacultural sustainability. Aquaculture America 2008. February 9-12, 2008, Lake Buena Vista, Florida.