Recipient Organization
UNIVERSITY OF GUAM UOG STATION
(N/A)
MANGILAO,GU 96913
Performing Department
Experiment Station
Non Technical Summary
Aquaculture has contributed to the Guameconomy in the past, surpassing $1M in the 1990's and early part of 2000, but did not continue its momentum of growth in recent years. Strict federal and state regulations on traditional fish farming in ponds and raceways are part of the reasons on Guam.Recirculation aquaculture systems (RAS) represent a new and unique alternative way to farm fish which rears fish at high densities, in tank with more controlled environment. Recirculating systems filter and clean the water for recycling back through fish culture tanks. New water is added to the tanks only to make up for splash out and evaporation and for that used to flush out waste materials. Fish grown in RAS are supplied with all the conditions necessary to remain healthy and grow. Continuous supply of clean water at a temperature and dissolved oxygen content that is optimum for fish growth are essential. A filtering (biofilter) system is incorporated to purify the water and remove or detoxify harmful waste products and uneaten feed. The fish is fed with nutritionally-complete feed on a daily basis to support adequate growth and survival. Aquaponicsintegrate aquaculture with hydroponics, which allows for the production of more plants (up to 12 x increases) with the fish waste (by product nutrient load). A decoupled aquaponic system has the potential to be a nearly zero-discharge system. This project of developing aquaponics RAS is intended for both research and training purposes. It would be an outdoor RAS with structures and materials proven to withstand winds approaching 100 mph, and electrical power which can be augmented or replaced with alternative power, such as solar and wind power. It would be used to evaluate the Tilapia/plant production, water quality management and economic analysis of the operation. The results of the project would directly benefit fish growers on Guam who may want to adopt such RAS for production and profit.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
Design and set-up appropriate commercial sized aquaponic system.Introduce the concept of a decoupled aquaponic system.Develop training materials for commercial aquaponic system.Conduct Train-the-Trainer workshops to appropriated local and federal government agencies.
Project Methods
Up to three independent recirculating aquaculture systems (RAS) will be established in the Aqua Park Area (100ft X50ft). The functional parts of each RAS would include a: (1) growing tank, (2) sump of particulate removal device, (3) biofilter, (4) aeration system, (5) water circulation pump and (6) biological aerated filter (BAF) alternative power supply with solar system will be considered for the system.1.Growing tank: 12 feet diameter circular tank with central drain and evenly sloped bottom floor will be constructed as rearing tank for Tilapia, as such design would facilitate the easy cleaning and circulation. Tanks can be constructed with typhoon proof material and structure, which could hold water, and do not corrode or be toxic to fish. Smooth surfaces on the inside of the tanks are recommended to prevent skin abrasions and infections to the fish, and to permit cleaning and sterilization.2.Sump: Circular tank with 6 feet in diameter will be used as the sump tank. A sump (clarifier tank) is used to prevent the excessive accumulation of fish excretory products and waste feed. The size of the clarification tank needs to be integrated with the sizes of the fish tank and biofilter and also with the turnover rate of the system (pump size). Volume of the sump and flow rates through the sump must be adjusted to maximize sedimentation of suspended particles.3.Biofiltration: 4 feet diameter circular tank filled with plastic media which provides large surface area on which nitrification bacteria can grow will serve as the biofilter tank. This biological filter (biofilter) is the heart of the RAS.4.Aeration: Successful fish production depends on good oxygen supply. Air blower and oxygen generator will be used for oxygen supply. Sufficient dissolved oxygen is essential to (1) the survival (respiration) of fish held in high densities, (2) the survival of aerobic, nitrifying bacteria on the biofilter and, (3) for the decomposition (oxidation) of organic waste products. Water: Dechlorinated tap water will be added in to compensate for evaporation and water loss in the waste removal.5.Recirculation rates: The recirculation rate (turnover time) is the amount of water exchanged per unit of time. Increasing the number of turnovers per day would provide increased biofiltration, greater nitrification (bacterial contact), and reduced ammonia levels. At least one complete turnover per hour (24 cycles per day) will serve as a guideline for the RAS model system initially with some adjustment as needed.6. Biolgical areated Filter (BAF): Sludge production from the fish tank will be collected in this filter to mineralize the solids, which can then be directed to the plant component of the overall aquaponic system. Undigested solids from this filter can be collected and disponsed of over terrestrial plants, compost piles, or other recycle strategies. This effluent is much less than nomal sludge removal in single pass aquaponic systems.7. Assess the economic feasibility (i.e., cost-benefit) of recommended operation management practices for aquaponic systems: Study design and analysis will follow previous work (Chen et al., 2018). A specific cost-benefit analysis framework as a mechanism to evaluate the progress metrics and establish assumptions for the analysis. This will provide a basis for current and prospectus aquaculture/aquaponics farmers to compare the total expect cost against total expected benefits.