Raceways Report PDF

RACEWAYS Phoebus Lindsay Sarmiento Cabanayan Advanced Aquaculture Dr. Remedios Bolivar College of Fisheries Central Luzon State University Science City of Munoz Nueva Ecija  Raceways also known as a flow- through system among the earliest methods used...

RACEWAYS Phoebus Lindsay Sarmiento Cabanayan Advanced Aquaculture Dr. Remedios Bolivar College of Fisheries Central Luzon State University Science City of Munoz Nueva Ecija  Raceways also known as a flow- through system among the earliest methods used for inland aquaculture usually consists of rectangular basins or canals constructed of concrete and equipped with an inlet and outlet.  Raceways A continuous water flow-through is maintained to provide the required level of water quality, which allows animals to be cultured at higher densities(10 to 15 fish per cubic foot) within the raceway also used for some marine species which need a constant water flow, such as juvenile salmon, brackish water seabass and seabream Raceway dimensions typically are 50 to 100 ft long, 10 to 30 ft wide, and 3 to 6 ft deep. Water flow through raceways usually is adequate to provide three or more exchanges per hour with a minimum velocity of about 0.1 ft/sec.  Site selection Water sources Streams Springs Reservoirs Deep wells  Monitoring of Water Quality water flow rates measurements pH levels temperature levels of dissolved oxygen suspended and solid waste material  Water flow needs to be sufficiently high to meet the respiratory requirements of the species concerned Existing water is largely replaced by new water when the same volume of new water enters the raceway Solid wastes which accumulate at the raceway bottom can be removed by pumps.  Water flow Oxygen levels in the water can be keep high if the raceway units are placed one after the other with intermediate drops over weirs water should be replaced about every hour The flow rate necessary to maintain water quality can also change through the year  Types of Raceways Construction Raceway ponds Earthen raceways with plastic liners Reinforced concrete Raceways tanks  Types of Raceways Raceway pond is a shallow artificial pond used in the cultivation of algae is divided into a rectangular grid, with each rectangle containing one channel in the shape of an oval Each rectangle contains a paddle wheel to make the water flow continuously around the circuit  Types of Raceways Raceway pond Smallest have been used for production of fish fry and were only 84 cubic feet in volume (6x4x3.5 feet) Largest have been used for catfish production and were approximately 670 cubic feet in total volume (24x8x3.5feet) Raceway pond used for the cultivation of microalgae. The water is kept in constantly motion with a powered paddle wheel.  Types of Raceways Earthen Raceways with plastic liners Cost little and are easy to build, but cleaning and disinfecting them is difficult because plastic linings are fragile  Types of Raceways Reinforced concrete/concrete silo The water from inlets is designed to be a driving force to circulate the water in the system, allowing the solid wastes removed through the outlet located in the center of the silo. The silos for seed production of trouts are small-sized (less than 1m in diameter) are often of FRP (fiberglass reinforced plastics).  Types of Raceways Raceway tanks Can also be build from polyester resin These tanks have smooth walls and are mobile and easy to service Their cost limits them to small size about 5 cubic meters  Technologies for removal of solid waste Microscreens dual-drain tanks swirl separators plate separators Baffles Technologies for removal of solid waste media filters air flotation foam fractionation chemical flocculation constructed wetlands- sedimentation (settling)  System of Operation Aerations  dissolved oxygen may be increased by aeration using some aerating machines, including pumps, agitators,compressor and blowers Aeration by pumping of the culture water in Aeration by water agitators in the trout the trout raceways raceways.  System of Operation Removal of solid waste matters Accumulation of waste matters in the raceway bottom spoils water quality Sucking the matters directly with the aid of pumping machine or it can be performed by increasing water flow in the raceways Lowering water level down to 30 cm in depth makes the removal more effective. Pumping out the waste matters accumulated at the bottom Raceway bottoms are regularly cleaned by total water drainage.  System of Operation Productivity Productivity of fish is strongly related with exchanging rate of the culture water. Productivity growth is important because more real income means that the system can meet its (perhaps growing) obligations to customers, workers, shareholders, and governments (taxes and regulation), and still remain competitive or even improve its competitiveness in the market place.  System of Operation Waste water treatment Waste water treatment is one of the crucial factors in the raceway operation. Bad treatment of the waste water often results in outbreaks of red tide in the reservoirs or rivers, causing a significant social problems.  Advantages Higher stocking densities Improved water quality Reduce manpower Ease of feeding Ease of grading Ease of harvest Less off flavor disease problems are easier to detect at earlier stages  Advantages disease treatments in raceways are easier to apply and require fewer chemicals than a similar number of fish in a pond (due to the higher density in the raceway) allow closer monitoring of growth and mortality Management inputs such as size grading are much more practicable  Disadvantages locating and securing a proper water supply is a major consideration large constant flows of consistent, high-quality water is needed commercial viability often requires that the water gravity flows through a series of raceways before it is released elevation of the water source and suitable topography for the gravity flow between raceways is required  Disadvantages Due to higher densities, more rapid disease spread, less reaction time when problem occur The culture density is directly dependent on the water flowing through the system. Because the water sources supporting the system normally come from streams or springs water which are colder than lakes or rivers, the system targets cold water fishes frequently cleaning of raceways is necessary Poaching THANK YOU!!!!