Recipient Organization
UNIV OF THE VIRGIN ISLANDS
(N/A)
ST. CROIX,VI 00850
Performing Department
Agricultural Experiment Station
Non Technical Summary
The UVI Commercial Aquaponic System (CAS) is an integrated aquaculture/hydroponic system which produces fish in the rearing tanks and vegetables. The integrated system conserves land and water by increasing production density in fiberglass tanks and plastic lined troughs and by the recirculation of water between the fish culture tanks and the hydroponic troughs. The overall objective of this multifaceted project involves the optimization of the commercial-scale aquaponic system, introduction of new high-value fish species, production efficiency, variety performance trials, system improvements, alternative sources of food and outreach. The specific objectives are: 1) Introduction of new fish species, 2) Aquaponics vs strict nutrient film technique (NFT) Hydroponics comparison, 3) Variety performance trials: crop introduction, plant production and impact on water quality, 4) Development of strategies to reduce power requirements and use photovoltaic energy to power Aquaponics systems, 5) Development of a hobby-scale system, 6) Improving the CAS, 7) Alternative sources of fish feed, and 8) UVI Aquaponics workshop. Our deliverables will be measured by the determination of alternative fishes adapted in tropical conditions to add more value to the system. Farmers will also be able to compare the efficiency of Aquaponics vs strict hydroponics systems focused only on vegetable production. The evaluation of different plant crops with alternative production capabilities will provide farmers with information which will help them diversify the crop production. The evaluation of alternative energy production scenarios such as solar, wind or mixed systems are necessary to reduce the energy dependence. The development of new management protocols for tilapia (Oreochromis niloticus) production and identification of improved and/or alternative system designs will increase the profitability of aquaponic technology for farmers. Systems will be developed that address both commercial growers' and hobbyists' requirements. Replacing the feed required by a locally produced resource would reduce the quantity of feed imported, potentially reducing the system footprint. Finally, the UVI Aquaponics workshop training continuation will allow the education of university students, professors, entrepreneurs, educators, extension agents and hobbyists. All those factors combined will improve the food security in the U.S. Virgin Islands, directly impacting our community.
Animal Health Component
80%
Research Effort Categories
Basic
20%
Applied
80%
Developmental
(N/A)
Goals / Objectives
The overall objective of this multifaceted project involves the optimization of the commercial-scale aquaponic system, introduction of new high-value fish species, production efficiency, variety performance trials, system improvements, alternative sources of food and outreach.Specific objectives:1) Introduction of new fish species2) Aquaponics vs strict NFT Hydroponics comparison3) Variety performance trials: crop introduction, plant production and impact on water quality4) Development of strategies to reduce power requirements and use photovoltaic energy to power Aquaponics systems5) Development of a hobby-scale system6) Improving the CAS7) Alternative sources of fish feed8) UVI Aquaponics workshop
Project Methods
Objective 1) Introduction of new fish speciesWe are comparing three fishes (pacus, tambaquis and tilapias) in round culture tanks, with three replications. The proposed measurements are environmental conditions, water quality parameters (pH, electrical conductivity [EC], temperature, dissolved oxygen [DO] and nutrient concentrations) and fish growth (feed conversion ratio, growth rate, weight and survival).Objective 2) Aquaponics vs strict NFT Hydroponics comparisonWe are comparing three systems (Aquaponics with low fish feed input [60 g/m2], Aquaponics with high fish feed input [100 g/m2] and strict NFT Hydroponics) and four crops and/or varieties with different nutrient requirements in each system. The proposed measurements taken are environmental conditions, water quality parameters (pH, EC, temperature, DO, nutrient concentrations and water use) and plant growth (height, number of leaves and yield).The research will be replicated using an organic nutrient source in the NFT system.Objective 3) Variety performance trials: crop introduction, plant production and impact on water qualityA series of variety performance trials will be conducted with the purpose of monitoring production practices and collecting production data including production volume, mass, quality and survival. Each will be produced for two crop cycles, eachtypically 90 days. Each will be evaluated under summer and winter seasonal conditions.Fruiting crops: cantaloupe, watermelon (Citrullus lanatus), tomato (Solanum lycopersicum), eggplant (Solanum melongena), hot pepper (Capsicum spp.), sorrel (Hibiscus sabdifera) and othersLeafy greens: collard (Brassica oleracea var. medullosa), endive (Cichorium endivia), lettuce, mustard (Brassica spp.), Chinese cabbage (Brassica rapa subsp. pekinensis), kale (Brassica oleracea var. sabellica) and othersCut flowers: carnation (Dianthus caryophyllus), lisianthus (Eustoma spp.), snapdragon (Antirrhinum spp.), sunflower (Helianthus annuus), ursinia (Ursinia speciosa), periwinkle (Catharanthus roseus), zinnia (Zinnia elegans) and othersObjective 4) Development of strategies to reduce power requirements and use photovoltaic energy to power Aquaponics systemsAn analysis will be made to determine if they can be resized and maintain production levels of fish and vegetables. A study will be conducted which will reduce power use by stopping aeration to the hydroponic beds for periods of time. A CR1000 data logger (Campbell Scientific, Logan, UT) will be used to measure dissolved oxygen (DO) levels. A control algorithm will open and close solenoid valves on the air supply lines. DO < 3.0 ppm will trigger valve opening, supplying air to the air stones and DO levels of 5 ppm sustained for 1-hr will trigger the valve to close. Ammonia-nitrogen and nitrite-nitrogen levels will be monitored daily to determine if nitrification is impacted by the reduced DO levels. Plant production will be evaluated by total yield and mean weight of the crop. Comparisons will be made with water quality and plant production in hydroponic beds having continuous aeration.Objective 5) Development of a hobby-scale systemA hobby-scale system will be developed with production goals of "one meal a week for a family of four" using readily available materials and supplies.Objective 6) Improving the CASDetermine growth, feed conversion ratio and survival of tilapia grown at different stocking rates and for different production periods.Evaluate water quality, fish and vegetable production at high pHEvaluate solid waste removal technologies and their impact on water quality, nutrient availability and production capacity.Objective 7) Alternative sources of fish feedWe will perform studies to evaluate the use of alternative sources of food to feed the tilapia in the CAS. One potential crop that can be produced with the sludge is duckweed, a plant that can be used as a fish feed. This research will evaluate raw, and several dilutions of sludge as a fertilizer for duckweed production. The best dilution will correspond to the result that produces duckweed with the highest protein content at a rate at which weekly cropping will supplement the fish diet by 10%. The duckweed will be incorporated into the diet of tilapia to determine its impact on their growth and feed conversion ratio.Objective 8) UVI Aquaponics workshopThe UVI Horticulture and Aquaculture research program will continue offering the UVI Aquaponics workshop. Workshop participants are focused on university students, professors, entrepreneurs, educators, extension agents and hobbyists. The UVI Aquaponics workshop will provide in-depth knowledge of the principles and practical application of the aquaponic system. Instruction is provided by both lectures and hands-on experience for participants.