Source: UNIV OF THE VIRGIN ISLANDS submitted to
TILAPIA AND SHRIMP CULTURE IN INTENSIVE,BACTERIAL-BASED, AERATED TANKS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0202503
Grant No.
(N/A)
Project No.
VI00-201094
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Jan 1, 2005
Project End Date
Dec 31, 2010
Grant Year
(N/A)
Project Director
Danaher, J. J.
Recipient Organization
UNIV OF THE VIRGIN ISLANDS
(N/A)
ST. CROIX,VI 00850
Performing Department
RESEARCH & LAND GRANT AFFAIRS
Non Technical Summary
The integration of shrimp culture with tilapia will be investigated to determine maximum allowable stocking density and economic return under polyculture conditions. A commercial-scale greenwater tank (200 m3) will be optimized with respect to water filtration and management to maximize production capabilities and economic return.
Animal Health Component
80%
Research Effort Categories
Basic
10%
Applied
80%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
3073714106035%
3073721106035%
6013714301015%
6013721301015%
Goals / Objectives
To determine growth, feed conversion ratio and survival of shrimp at two densities and assess operational considerations for monoculture, shrimp production in the 30m3, low salinity, greenwater systems. To develop a floating/supported net-pen structure to separate the tilapia and shrimp for a polyculture growout trial. Using evidence from the completion of Objective l, the production limits of the greenwater, polyculture system will be evaluated. To optimize the minimum filtration requirements for sustained,near zero water exchange production. To evaluate the overall profitability of raising shrimp in a commercial-scale, recirculating tank.
Project Methods
Marine shrimp, Litopenaeus vannamei, will be acquired from a supplier in the Dominican Republic and acclimated to a near-freshwater salinity of 2 ppt. They will be stocked for a 5 month growout period and the results will be evaluated to assess the maximum stocking density for acceptable survival, growth, and economic return. A maximum combined stocking density will be determined for both tilapia and shrimp in an optimized greenwater system. Economic analysis will be conducted to determine the viability of freshwater shrimp culture in a greenwater system.

Progress 01/01/05 to 12/31/10

Outputs
OUTPUTS: Presentations were made at the World Aquaculture Society meeting in Veracruz, Mexico. Peers in academia and stakeholders within the industry are very interested in the work being done reusing for intensive production of tilapia and reusing discharged wastes for agricultural production. Results from the research trials were shared with stakeholders from throughout the Caribbean at the 38th Annual Food and Agricultural Fair on St. Croix. It is the largest agricultural venue in the Greater and Lesser Antilles allowing farmers throughout the Caribbean to learn about biofloc systems and their capabilities on islands with limited freshwater resources. Also, the Aquaculture Program held its Annual International Aquaponic and Tilapia Course and taught 120 individuals from all over the world the management and production capability of the biofloc system. PARTICIPANTS: World Aquaculture Society members, Researchers from other institutions, University of the Virgin Islands Aquaculture Program staff and students as well as researchers within the Southern Regional Aquaculture programs and neighboring areas. TARGET AUDIENCES: University of the Virgin Islands Aquaculture Program staff and students as well as Aquaculture Researchers from other institutions and in Southern Regional Aquaculture programs and neighboring areas. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The Aquaculture Program continues to investigate methods of integrating the biofloc production system with traditional agronomic crop production and also is investigating technologies to further enhance use of freshwater resources with the biofloc production system. An experiment was begun to evaluate the potential use of a Quick Tank for biofloc production of tilapia. The Quick Tank is an inexpensive round tank consisting of a 20 mil liner supported by a four-foot high plastic coated fencing along the tank's perimeter. The tank used in the experiment has a diameter of 30 feet and volume of 18,500 gallons. The tank can be installed in less than three hours and is a non-permanent structure. This scenario helps farmers in the Virgin Islands because many of them who lease government land cannot construct permanent structures. The tank was stocked with 1,750 Nile tilapia fingerlings and in five months is supporting a tilapia biomass of approximately 15 kg/m3.

Publications

  • No publications reported this period


Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: Two presentations were made at the 2009 World Aquaculture Society meeting in Veracruz, Mexico. Peers in academia and stakeholders within the industry are very interested in the work being done reusing for intensive production of tilapia and reusing discharged wastes for agricultural production. Results from the research trials were shared with stakeholders from throughout the Caribbean at the 38th Annual Food and Agricultural Fair on St. Croix. It is the largest agricultural venue in the Greater and Lesser Antilles allowing farmers throughout the Caribbean to learn about biofloc systems and their capabilities on islands with limited freshwater resources. Also, the Aquaculture Program held its Annual International Aquaponic and Tilapia Course and taught 56 individuals from all over the world the management and production capability of the biofloc system. PARTICIPANTS: The project provided opportunity for professional development by allowing the researchers to attend the 2009 World Aquaculture Society Meetings in Veracruz, Mexico. The topic was shared with peers and information and ideas were exchanged for future projects. Researchers from other institutions are contacting the University of the Virgin Islands Aquaculture Program about reusing aquaculture effluent for vegetable crop production. This research with integrating the biofloc production system with agronomic crops has allowed for increased contacts within Southern Regional Aquaculture and neighboring areas. TARGET AUDIENCES: The target audiences are farmers in the territory, entrepreneurs, and education personnel. Farmers and entrepreneurs would like to see the capability of the biofloc system for tilapia production. Production of a fresh, locally grown fish in an area where the majority of food is imported could increase income for the producers. Farmers have formed organizations to strengthen agriculture practices in the territory. They are looking for new technologies to enhance their production capabilities. They are hopeful the biofloc system will provide them with options for their personal production needs. Many of the farmers are producers of agronomic crops and a transfer of new technology will require a transitional period;however, if the technology is applicable the farmers will adopt it. PROJECT MODIFICATIONS: As stated in last year's report, the project has been modified. Researchers believe that demonstration of successful integration with traditional agriculture will further increase biofloc interest and awareness to stakeholders in the Caribbean and peers at other agricultural institutions.

Impacts
The Aquaculture Program continues to investigate methods of integrating the biofloc production system with traditional agronomic crop production and also is investigating technologies to further enhance use of freshwater resources with the biofloc production system. An experiment was begun to evaluate the potential use of a Quick Tank for biofloc production of tilapia. The Quick Tank is an inexpensive round tank consisting of a 20 mil liner supported by a four-foot high plastic coated fencing along the tank's perimeter. The tank used in the experiment has a diameter of 30 feet and volume of 18,500 gallons. The tank can be installed in less than three hours and is a non-permanent structure. This scenario helps farmers in the Virgin Islands because many of them who lease government land cannot construct permanent structures. The tank was stocked with 1,750 Nile tilapia fingerlings and in five months is supporting a tilapia biomass of approximately 15 kg/m3. Final data will be taken the first quarter of 2010.

Publications

  • Danaher, J.J. Evaluating Geotextile Technology to Enhance Sustainability of Agricultural Production Systems in the U.S. Virgin Islands. Technical Bulletin 14 from the University of the Virgin Islands Agricultural Experiment Station. August, 2009, 4pp.
  • Danaher, JJ,JE Rakcoy, RC Shultz and DS Bailey. 2009. Applications for Reclaimed Aquaculture Effluent from a Commercial Biofloc System. World Aquaculture 2009., Sept 25-29, Veracruz, Mexico.
  • Danaher, JJ, JE Rakocy, RC Shultz and DS Bailey. 2009.Tilapia (Oreochromis niloticus) Production Trials in the University of the Virgin Islands' Biofloc System. World Aquaculture 2009, Sep 35-29, Veracruz, Mexico.
  • Shultz, RC, JJ Danaher and JE Rakocy. 2009. Evaluation of two textiles with or without polymer addition to assess TSS removal efficiency in biofloc effluent. World Aquaculture 2009, Sep 25-29, Veracruz, Mexico.
  • Danaher, JJ and JE Rakocy. 2009. Reclaimed aquaculture effluent for use on cucumber Cucumis sativus cv Eureka grown in the U S Virgin Islands. Aquaculture America 2009, February 15-18, Seattle, Washington.
  • Danaher, JJ, R.S. Shultz, and J.E. Rakocy. 2009. Evaluation of two textiles with or without polymer addition for dewatering Nile tilapia, Oreochromis niloticus, effluent. Journal of the World Aquaculture Society (in press).
  • Danaher, J.J., E. Pantanella, J.E. Rakocy, R.C. Shultz and D.S. Bailey. 2009. Dewatering and Composting Aquaculture Waste as a Growing Medium in the Nursery Production of Tomato Plants. ISHS International Symposium on Growing Media and Composting. North Carolina State University, 1-5 June, Raleigh, NC (in press).
  • Pantanella, E., JJ Danaher, J.E. Rakocy, R.C. Shultz and D.S. Bailey. 2009. Alternative media types for greenhouse seedling production of lettuce and basil. ISHS International Symposium on Growing Media and Composting. North Carolina State University, 1-5 June, Raleigh, NC (in press).
  • Danaher, JJ 2009. Evaluating Geotextile Technology to Integrate Agricultural Production Systems in the U.S. Virgin Islands. 18th Annual Caribbean Water and Wastewater Association Conference, Oct. 4.


Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: A presentation was made at the 2008 Aquaculture America meeting in Florida. Peers within the industry are very interested in the work done reusing aquaculture effluent as a fertilizer. The Aquaculture Program held its Annual International Aquaponic and Tilapia Course and taught 73 individuals from all over the world the management and production capability of the biofloc system. An additional 6 week short course was held for a local farmer's cooperative consisting of 35 individuals. They were taught the daily management protocols for operating the biofloc system. PARTICIPANTS: The project provided opportunity for professional development by allowing the researchers attend the 2008 Aquaculture America meeting in Florida. The topic was shared with peers and information and ideas were exchanged for future projects. Researchers from other institutions are contacting UVI about reusing aquaculture effluent for vegetable crop production. This research with integrating the biofloc production system with agronomic crops has allowed for increased contacts within Southern Region Aquaculture and neighboring areas. TARGET AUDIENCES: The target audiences are farmers in the territory, entrepreneurs, and education personnel. Farmers and entrepreneurs would like to see the capability of the biofloc system for tilapia production. Production of a fresh, locally grown fish in an area where the majority of food is imported could increase income for the producers. Farmers have formed organizations to strengthen agriculture practices in the territory. They are looking for new technologies to enhance their production capabilities. They are hopeful the biofloc system will provide them with options for their personal production needs. Many of the farmers are producers of agronomic crops and a transfer of new technology will require a learning curve; however, if the technology is capable of producing what the farmers want it could be adopted. PROJECT MODIFICATIONS: The project has been modified. Past experiments have demonstrated the production of shrimp in the biofloc system was not practical as a result of water quality and possible tilapia predation in polyculture systems. The biofloc system is somewhat unstable in water quality compared to other recirculating systems and in a low salinity environment the water parameters were lethal to shrimp. Also, there are a limited number of hatcheries in the western hemisphere where specific pathogen free post larvae (PL) are available, which makes PL difficult to obtain for experiments. Increased shipping costs, reduced flights throughout the Caribbean, and reduced commercial airlines willing to accept live animals makes it almost impossible and impractical to consider shrimp production in the U.S. Virgin Islands at this time. Therefore, efforts have shifted to maximizing the use of nutrients and water discharged from the biofloc system to improve agronomic crop production and soil properties in the territory. Geotextile bags and alternative textiles have been evaluated through this grant to dewater biofloc effluent for integrated production purposes. Researchers believe that demonstration of successful integration with traditional agriculture will further increase biofloc interest and awareness to individuals in the Caribbean and other agricultural institutions.

Impacts
A fourth commercial biofloc production trial was completed in the 200 m3 system. Bird netting was installed over the tank to prevent bird predation on fish throughout the experiment. Results of the experiment were tilapia survival and productionof 99.5% and 3,680 kg, respectively. The final biomass density reached 18.0 kg/m3. This improvement in survival and biomass demonstrates the commercial biofloc system is 37 times more productive than traditional pond production of tilapia. Geotextile material has been used to dewater aquaculture effluent. An experiment was conducted to evaluate burlap as an alternative, less expensive and more sustainable material to reduce TSS levels in discharged aquaculture effluent. Effluent was taken from a 200-m3 commercial biofloc system. The effluent was either injected or not injected with a polymer prior to entering the geotextile bags or burlap bags. Results demonstrate there was no significant difference in water quality parameters measured with TSS concentrations being reduced by 95% using either textile in conjunction with the polymer. Therefore, burlap may replace geotextile for treating aquaculture effluent; thus making the treatment process more cost-effective and sustainable. A geotextile bag was used to dewater aquaculture efluent. The dewatered solids were used as a fertilizer and compared to a commercial fertilizer for cucumber production in field plots. Results found the aquaculture manure applied at a rate of 90 lbs nitrogen/acre resulted in similar cucumber production as 90 lbs nitrogen/acre of Osmocote and application rates of >90 lbs nitrogen/acre did not improve cucumber yield. There was no difference between the 6 different treatments tested with an average production of 55 mt/ha of marketable cucumbers. The biofloc system discharges effluent containing organic matter and nutrients on a daily basis, thus dewatering and composting effluent may provide a practical growing medium to nurse plants. Composted aquaculture effluent was compared to PRO-MIX as a media for growing tomato seedlings. The two PRO-MIX treatments either did receive (Control) or did not receive fertigation with a water-soluble inorganic fertilizer during seedling production, while seedling nutrition was entirely based on the mineral nutrients available from the three different ratios of composted aquaculture effluent. Results indicated composted aquaculture effluent may be substituted as a local, alternative growing medium for nursery production of tomato plants. A new species of fish was considered for the biofloc system. The catfish, Pangasius spp., was obtained from Puerto Rico; however, the fish were infected with monogenetic trematodes and were destroyed to prevent disease transfer throughout the aquaculture facility.

Publications

  • Danaher, J.J., J.E. Rakocy, D.S. Bailey, R.C. Shultz, and K. Lincoln. 2008. Use of a Geotube for recovery of aquaculture wastewater for agronomic crops cultivated in the U.S. Virgin Islands. Aquaculture America 2008, Disney's Coronado Springs Resort, Lake Buena Vista, Florida, USA, February 9-12.


Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: Results of this project were shared with researchers and farmers. A presentation was made at the 2007 Caribbean and Latin American Aquaculture meeting in Puerto Rico. This allowed knowledge transfer between peers within the aquaculture industry. The Aquaculture Program held a short course on our production systems, including biofloc, and sixty-five individuals from all seven continents were able to tour and ask many questions on the design and production capability of the biofloc system. The information pertaining to the biofloc system was shared at a 2007 farmers' meeting to show the benefits of the biofloc system in water use and potential for nutrient recycling with agronomic crops. A short course offered to farmers in the territory will highlight the capabilities of the biofloc system. PARTICIPANTS: The project provided opportunity for professional development by allowing the PI to attend the 2007 Caribbean & Latin American Aquaculture meeting in San Juan, Puerto Rico. The topic was shared with peers and information and ideas were exchanged for future projects. The PI and a research analyst worked together throughout the experiment. The PI carried out the daily management of the production systems and the research analyst performed the necessary water quality tests. TARGET AUDIENCES: The target audiences are farmers in the territory, entrepreneurs, and education personnel. Farmers and entrepreneurs would like to see the capability of the biofloc system for production of shrimp. Production of a high-commodity animal in an area where the majority of food is imported could increase income for the producers. Farmers have formed organizations to strengthen agriculture practices in the territory. They are looking for new technologies to enhance their production capabilities. They are hopeful the biofloc system will provide them with options for their personal production needs. Many of the farmers are producers of agronomic crops and a transfer of new technology will require a learning curve, however, if the technology is capable of producing what the farmers want it will be adopted and understood. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Many short course students and farmers in the territory inquire about producing shrimp and tilapia together in the biofloc system. Our experiment demonstrating additional considerations are required to ensure animal health and production. The traditional UVI biofloc design is dependent on the free roaming tilapia to help suspend the floc in the tank. The importance of free roaming fish was demonstrated in this project by lower concentrations of suspended matter compared to previous biofloc studies. Caged fish may require additional technology to accomplish the suspension process. With reduced efficiency in the suspension process water quality was a major problem. Addition of a biofilter or increase of salinity may be required to improve environment for shrimp growth. The impact of this study is important because it demonstrates a simple procedure for separating fish from shrimp in a polyculture system was not effective. Additional planning and resources will be required to improve water quality and animal health in the future.

Publications

  • Danaher, J.J., J.E. Rakocy, D.S. Bailey and R.C. Shultz. 2007. The effect of polyculture of monosex maile Nile tilapia Oreochromis niloticus and two densities of Litopenaeus vannamei on growth, total production and water quality in a low-salinity, biofloc system. Caribbean & Latin American Aquaculture 2007, November 6-9, San Juan, Puerto Rico, USA.


Progress 01/01/06 to 12/31/06

Outputs
A low-salinity (5 part per thousand salt), polyculture study was performed to determine the effects of monosex male tilapia in cages effect on shrimp growth, survival and water quality parameters. Two treatments with three replicates each were used. Both treatments had four, l cubic meter cages stocked with 100 tilapia. Fish were stocked (April 2007) two months prior to shrimp stocking. This allowed the system to become acclimated. Shrimp were stocked in June 2007 at two different rates according to treatment: 44 or 88 shrimp per square meter. Fish were fed ad libitum twice per day for twenty minutes. Shrimp were fed according to a feed chart and sampled every two weeks for feed rate adjustment. Water quality parameters were monitored biweekly. Preliminary observations suggest that nitrogenous wastes levels are sub-optimal for shrimp health and that additional biofiltration may be required to provide the proper culture environment. In September 2007, fish, shrimp and water quality data will be analyzed to determine which stocking density had a positive influence on final tilapia and shrimp average weight, total system production (tilapia + shrimp)and water quality. The treatment with the desired results will then be reconsidered for future experiments with tilapia/shrimp polyculture.

Impacts
The current experiment, although not completed as of yet, suggests the low-salinity polyculture production system may need some additional components to improve water quality for the shrimp. Farmers in the territory should postpone thoughts of producing shrimp in the current biofloc system design until additional research can be initiated.

Publications

  • No publications reported this period


Progress 01/01/05 to 12/31/05

Outputs
Objective 3 of this project was studied to optimize the minimum filtration requirements for sustained, near-zero water exchange tilapia production. Previous research demonstrated that the greenwater system had an efficient denitrification process, resulting from denitrifying bacteria colonizing suspended matter. Oxidation of ammonia and nitrite led to sub-optimal levels of nitrate (>700 ppm) in the system that affected tilapia production. In an attempt to decrease nitrate levels, two denitrification troughs (15m x 1.3m x 0.46m) were incorporated into the greenwater tank design as areas for anaerobic activity and assigned flow rates of 3 liters/minute or 6 liters/minute for 24-hr or 48-hr retention, respectively. In December 2004, a 200-m3 preconditioned commercial, greenwater tank was stocked with 5,000 juvenile tilapia. Throughout the study, water quality was analyzed biweekly to determine dissolved oxygen, pH, alkalinity and nitrogenous waste levels present in the production system. After 26 weeks the tank was seined and then drained for harvest. Tilapia survival was 86% with an average weight of 707 g, a feed conversion ratio of 1.8 and total production averaging 15.3 kg/m3. These parameters were marked improvements from previous trials. Bird predation resulted in low survival and system modifications will be done to decrease this in the future. Water quality parameters were optimal for those reported for tilapia. The denitrification trough with a 48-hr retention nearly doubled the removal of nitrate; however, nitrate levels were found to increase throughout the experiment in the culture tank reaching a final concentration of 341 mg/L; nonetheless, final levels were reduced by nearly 50% from previous culture experiments since the incorporation of an external clarifier and the denitrification troughs. Anaerobic tolerant plants could be placed in the troughs to further reduce nitrate levels.

Impacts
Aquaculture in the Virgin Islands is limited as a result of topography, available land, and a limited water supply. Intensive recirculating systems with near zero water exchange, like the one in this project would be ideal for a developing industry on the island. Previous trials have demonstrated that the system removes solids and oxidizes nitrogenous wastes efficiently; however, this has led to a buildup of nitrates in the culture system. Limiting the accumulation of nitrates is important to fish health and growth. By concentrating and removing solids and reducing nitrate levels, the system is capable of providing an optimal environment for intensive tilapia culture. This system would provide a farmer with an intensive production system and semi-intensive management practices capable of supplying fresh fish products to the territory.

Publications

  • No publications reported this period