Location: Warmwater Aquaculture Research Unit
Project Number: 6066-13320-005-00-D
Project Type: In-House Appropriated
Start Date: Nov 3, 2014
End Date: Oct 27, 2019
The overall objective of this project is to increase profitability of catfish aquaculture by improving farm-level production efficiency. This will be accomplished by developing new production systems and management practices that allow greater control of the culture environment, with the end result that the genetic potential of catfish can be fully expressed. Studies will also be conducted on the use of ultrasound to kill the intermediate host of an important catfish pathogen and reduce bacterial loads in processing plant cold-water washes. Over the next 5 years, we will accomplish the following objectives: 1) Enhance Control of Pond-Based Ecosystems to Maximize Production and Product Quality. Sub-objective 1.1 Optimize split-pond design for food-sized catfish aquaculture. Sub-objective 1.2 Maximize catfish production potential of conventional ponds using intensive aeration. Sub-objective 1.3 Evaluate management practices to reduce the final size variation resulting from variable growth rates in hybrid catfish. 2) Determine the Suitability and Feasibility of Polyculture or Off-season Production of Other Species Using Catfish Culture Infrastructure. Work on this objective will focus on developing technologies for production of a secondary, non-catfish species, such as tilapia, in split-ponds. Production of secondary filter-feeding species can potentially increase on-farm profits by generating an additional crop at little extra expense and may improve water quality in split-pond systems by feeding on plankton and detritus that are an oxygen-consuming waste product in catfish monocultures. 3) Develop Acoustic Technology and Methodologies to Improve the Production and Profitability of Pond-based Aquaculture in the United States. Sub-objective 3.1 Develop and test the potential for control of ramshorn snails in ponds using ultrasound. Sub-objective 3.B. Develop and test the potential for ultrasound to reduce bacteria in the cold-water wash in processing plants. Work on this objective will be conducted using congressionally mandated funds administered through Specific Cooperative Agreement 58-6402-9-427 (“Development of Active and Passive Acoustic Measurements to Improve Production and Profits of U.S. Aquaculture”) between the ARS Warmwater Aquaculture Research Unit, Stoneville, MS, and the National Center for Physical Acoustics, at the University of Mississippi. Under this Agreement and as part of this Project Plan, novel application of acoustic technology will be tested and developed, including Sub-objective 3.A, developing and testing the potential for control of ramshorn snails (a disease vector in catfish ponds) using ultrasound, and Sub-objective 3.B, reducing bacteria in the cold-water wash in catfish processing systems using acoustic cavitation.
Four, 7-acre earthen ponds at the National Warmwater Aquaculture Center at Stoneville, Mississippi, will be modified into split-ponds (Sub-objective 1.A). Pump-performance curves will be developed by systematically changing pump operational parameters for four pump types—one pump for each split-pond. High aeration rates will be used to culture hybrid catfish (channel catfish x blue catfish) and measured variables will include fish growth, survival, production, processing yield, feed conversion ratio, dissolved oxygen concentrations, and water quality variables measured biweekly. Relationships among average flow rate (pump type) and fish growth, feed conversion ratio, and selected water quality variables for each year over the 3-year study will be assessed using regression analysis and results will yield different options for farmers using this technology in the industry. Six, 0.25-acre ponds with 24 horsepower/acre of aeration for hybrid catfish production will be used in this study (Sub-objective 1.B). Dissolved oxygen, temperature and aerator status will be continuously monitored and the aerators controlled using a pond oxygen monitoring and control system already in place. Water quality will be measured biweekly for hybrid catfish production. Response variables will include final fish weight, weight gain, net production, processing yields, survival, feed consumed, feed conversion ratio, aerator usage), and economics Relationships among stocking rate, aerator usage, feed consumed, weight gain, feed conversion ratio, and selected water quality variables will be assessed using regression analysis. This model should allow us to recommend a stocking rate that will allow satiation feeding through the growing season and will be tested on commercial ponds. Twelve, 1-acre ponds (10-hp of aeration per acre) will be used to produce hybrid catfish at the Delta Branch Experiment Station, Stoneville, MS (Sub-objective 1.C). Production parameters, coefficients of variation in size, and final economics will be compared among treatments using analysis of variance. Pending the results from this study, further studies on hybrid catfish foodfish management practices to reduce growth rate variation, including feeding schedules and practices, will be conducted. For Sub-objective 2, a 4.5-acre split-pond aquaculture system located at the National Warmwater Aquaculture Center in Stoneville, Mississippi will be modified for to allow for the production of hybrid catfish and Blue Tilapia. Production performance will be measured and a performance average will be taken after three production seasons and a partial budget developed to measure gauges of economic efficiency of this production method as compared to conventional split-pond catfish aquaculture. Experiments will be conducted on groups of snails using a commercially available sonicator as the acoustic source to destroy snails (Sub-objective 3.A). The potential use of ultrasonic cavitation to reduce bacteria in the cold-water wash in processing plants will be investigated as well in Objective 3.B. A cost-benefit comparison must be made to determine if the proposed design and technique is warranted.