Video credit: Marx Perfecto C. Garcia (Philippines)
Description: Abdel Rahman El Gamal (Founder of the video channel)
Historic information: As reported, the “In-pond raceway technology – IPR” was first developed in 2007 on a channel catfish farm in West Alabama, USA. Afterwards, the technology was transferred to China in 2013 and then after to more Asian countries including Vietnam, and India). Currently, the technology has been introduced to more countries around the global.
System description: The system relies on the creation of water circulation within the raceway units located in earthen ponds as well as on the removal of the organic wastes. The water circulation is done using paddlewheel aerators and/or air blowers. The use of low speed paddlewheels provides a constant water current through the raceways. The aerators should be of capacity sufficient to create water flow of enough volume with particular velocity in the raceway cells which ultimately determines the frequency of water renewal within the raceway that in turn is a function of several parameters including the species, stocking density, and fish biomass.
This video was filmed in the Freshwater Fisheries Research Center (FFRC), Wuxi, China.
In regard to the waste removal, the water and sludge are moved from the raceways into a waste-settling zone in the open pond from where the water is filtered before re-circulation, while the organic wastes are periodically collected using mechanical collectors. The organic waste products in the open pond are carried into the open pond area where they are processed naturally and in the same time stimulate the growth of natural organisms that in-turn become a good food for other fish species especially in the open pond.
Typically,the raceways are constructed in parallel in a chosen corner of a traditional earthen pond with a center baffle to provide for a continuous circulation pattern around the pond and through the raceways.
Applications: The application of the IPR technology has been promoted as a means to enhance aquaculture production of good quality fish and in the same time achieve a best utilization of water resources. That is why the technology has been encouraged in situations of water scarcity or high cost of natural resources such as land and water especially when the intensification of farming practices is targeted.
Several species have been grown in the IPR systems including and not limited to carps, channel catfish, paddlefish and others. Because of the cost involved in the establishment and operation of this system, high market value fish are often targeted.
Advantages: The IPR as mentioned ultimately targets higher production of high quality fishery products that result from healthy environment that ensures higher growth rate and survival, efficient feed conversion ratio and other productive traits.
Depending on the overall conditions and practices, the increase of the system productivity has varied significantly and ranged from as low as low as 50% to as high as 300%. Moreover, the environmentally nature of the system, the no water discharge from production ponds to outside eliminates the possible negative impacts to the environment. The sustainable utilization of water resources is considered a key advantage for the IPR system especially when compared to the traditional raceway system depends on high-flow rate of incoming water with no reuse of discharged water. The choice of the raceway fish and the co-cultured species would vary depending on the production target. An example for that is culture of channel catfish (Ictalurus punctatus) in the raceway facility, while the paddlefish (Polyodon spathula) is grown as a co-cultured species in the open pond. In a production arrangement as such, the main cultured species which is channel catfish enjoys the best water quality in the raceway. Also, the open pond system provides a safe and stress-free environment to the paddlefish (co-cultured species).
