Advanced Aquaculture Technology PDF

Advanced Aquaculture Technology Prof. Gourav Dhar Bhowmick Agricultural and Food Engineering Department, IIT Kharagpur Module 02: Technology of Closed Aquaculture Lecture 01: Transformation of open culture to closed high-tech technologies  Concepts...

Advanced Aquaculture Technology Prof. Gourav Dhar Bhowmick Agricultural and Food Engineering Department, IIT Kharagpur Module 02: Technology of Closed Aquaculture Lecture 01: Transformation of open culture to closed high-tech technologies  Concepts Covered Types of Aquaculture Open Aquaculture Systems (OASs). Demerits of OASs. Closed Aquaculture Systems (CASs). Key elements of CASs. How CASs mitigates the inadequacies of open systems Types of Aquaculture There are different types of aquaculture – I. Depending on Hydrobiological Features II. Depending on the Motive of Farming III. Depending on Special Operational Techniques Various types of cultural practices are carried out in each of these divisions. Some have been discussed here. 1. Mariculture 2. Flow-through / Raceway 3. Algaculture 4. Integrated Multi-Trophic Aquaculture(IMTA) 5. Inland Pond Culture 6. Recirculating Systems 7. Open-net pen and Cage Systems etc. Open Aquaculture System [OAS] Involves rearing of aquatic organisms within enclosed systems, in natural environments like freshwater rivers, coastal marine regions and brackish estuaries. Utilizes floating mesh cages anchored to the seafloor. Sea-cage Seabream, seabass, codfish, tilapia, salmon, and shark catfish (active feeding) are some organisms cultured in such OASs. Cultured species rely on a fish-meal diet. Types Sticks, racks, Utilizes sticks, ropes, or cages as modes of attachment. ropes, and cages Mainly cultured species are mussels and oysters. (passive feeding) Cultured species are filter-feeders, doesn’t require fishmeal diet.  Sea-cage based OAS Sticks, racks, ropes, and cages based OAS Source: https://goodfishbadfish.com.au/aquaculture-methods/  Demerits of OASs Requires fishmeal for feeding carnivorous species. Poor conversion ratio. For example: Sometimes 5kg of fishmeal is required to breed 1kg of fish. High fish densities result in increased disease and parasite transmission. Risk of escape. Interbreeding with wild populations. Accumulation of fecal waste reduces water quality. Disposal of sticks and racks becomes a concern in some areas.  Closed Aquaculture System [CAS] Involves land-based breeding of aquatic organisms in ponds, raceways, and tanks. Maintains a controlled interface between the reared species and the natural environment Implements a highly sophisticated waste management procedure that filters the generated wastewater and cycles it back into the aquaculture system. Recirculating aquaculture system is a typical example of a CAS. Atlantic salmon, Cobia, Catfish, Tilapia, and European bass are some aquatic species reared in CASs. SEMI-CLOSED AQUACULTURE SYSTEMS CLOSED AQUACULTURE SYSTEM Source: https://goodfishbadfish.com.au/aquaculture-methods/  Re-circulatory aquaculture system: A type of CAS Source: https://thefishsite.com/articles/top-tips-for-setting-up-a-recirculating-aquaculture-system-part-2  Key elements of a CAS Monitoring Fish handling Feeding: Artificial diet (fishmeal, fertilizers) Filtration unit: Particulate matter removal, biofilter, etc. Temperature control: water heating system (optional, depending on water temperature and selected fish species). Aeration unit Ozone/ultraviolet sterilization: Reduces bacterial and organic loads. What makes CAS better than OAS? Maintains water quality due to negligible interference with natural waterways. Sophisticated waste management procedures. Prevents fish escape to surrounding waters. Reduced transmission of fish diseases and parasites. Improved fish quality and superior growth rates Better food conversion efficiency Reduced dependency on therapeutics.  CONCLUSIONS Open Aquaculture System (OAS) has been the most preferred aquaculture system over the years. OAS, however, possesses high environmental risks due to its direct contact with the natural waterways. Thus, the focus has now shifted towards closed aquaculture systems (CAS). CASs involve highly sophisticated waste management systems for solid waste removal and biological filtration, thereby improving the water quality and making the water reusable several times, before being discarded. REFERENCES M. A. Oyinlola, “Mariculture: perception and prospects under climate change,” Predict. Futur. Ocean. Sustain. Ocean Hum. Syst. Amidst Glob. Environ. Chang., pp. 227–239, Jan. 2019, doi: 10.1016/B978-0-12- 817945-1.00019-8. S. Goddard and M. Delghandi, “Importance of the Conservation and Management of Freshwater to Aquaculture,” Encycl. World’s Biomes, vol. 4–5, pp. 35–44, Jan. 2020, doi: 10.1016/B978-0-12-409548- 9.11954-2. https://abcofagri.com/recirculating-aquaculture-systems/ https://seawatercubes.de/en/open-aquaculture-systems/ https://goodfishbadfish.com.au/aquaculture-methods/  Advanced Aquaculture Technology Prof. Gourav Dhar Bhowmick Agricultural and Food Engineering Department, IIT Kharagpur Module 02: Technology of Closed Aquaculture Lecture 02 : Intensive farming in high-tech tanks  Concepts Covered Comparison between extensive, semi-intensive, and intensive aquaculture systems. Intensive aquaculture system Intensive farming in high-tech tanks Zero water discharge (ZWD) system  Introduction Based on production intensity there are three different aquaculture systems: Extensive Semi-Intensive Intensive Least managed Requires moderate Best managed Depends on natural input Depends on artificial resources for Fertilizers/supplement feed nutrients ary food may be Very high Low productivity added productivity (1000 kg/ha/year) Moderate productivity (c.1,340,000 (3-10 ton/ha) kg/ha/year)  Extensive Semi-Intensive Intensive Source: https://aquacultures.wordpress.com/2011/10/09/global-trends-in-aquaculture/ Intensive aquaculture system Involves rearing fishes in artificial tanks, ponds, cages, and raceways at very high stocking densities. Facilitates maximum fish production from a minimum amount of water. Reared fishes are fed artificial food while natural feed plays a minor role. Requires high inputs of energy (e.g. nutrients, feed, filtration, aeration, pumping)  High yields per unit area or volume (over 6000 kg/ha/year). Involves high cost of investment. However, overall returns exceed operational costs ensuring higher profits. Low energy losses from feed input. High food conversion ratios from specific artificial feeds. Figure 1: System map of intensive aquaculture systems. GHG: greenhouse gasses  Intensive farming in high-tech tanks Culturing breeds for 2-3 months into fingerlings within tanks (area: 0.05-0.1 hectare). Based on shape, there are three type of tanks: Circular Simple maintenance Effective water usage. Facilitates self-cleaning action.  Primary flow facilitates uniform water distribution in the horizontal plane, while the secondary flow leads to cleaning of the tank walls and bottom Source: https://www.brainkart.com/article/Flow-pattern-and-self-cleaning---Aquaculture-Engineering_15092/ Continued……  Maintains uniform water quality Supports operation at a wide range of rotational velocities for maintaining fish health/condition Facilitates rapid flushing of settleable solids through the center drain Typical size: 12 to 30 feet (diameter), 4 to 5 feet (depth) Ideal for rearing tilapia. Rectangular Can be built very quickly and provides good space efficiency Have poor flow characteristics leading to waste accumulation and reduced aeration Oval Possesses the benefits of both circular and rectangular tanks Microbial-based closed intensive farming system Biofloc – Low/no water discharge – Improved system from the batch system – Add carbon source to enhance heterotrophic bacteria consortium – Emphasize in C/N ratio in the system – ‘waste’ Nitrogen is converted to a high concentration of total suspended solids (microbial biomass) that can act as highly protein feed for cultured animal – Consider well mixing and aeration to compensate for BOD in the system Periphyton – Low/no water discharge – Improved system from the batch system – Need organic substrate i.e. bamboo to periphyton attachment – Input organic matter i.e. manure and chemical fertilizers to trigger periphyton growth – Sometimes, needs additional carbon source to maintain C/N ration in the system – Periphyton acts as nitrogen toxic removal system and food source for cultured animal Microbial-based closed intensive farming system (Cont.) RAS (Recirculatory aquaculture system) – No water discharge – Many treatment processes are involved including physical and chemical treatment – Microbial compartment is in the biofilter – Biofilter has defined microbial consortia – Isolated and clear-water system – The main purpose is biologically secure and hygiene aquaculture product – Investment cost and operational cost is higher than other systems Green water technique Low water discharge – Use batch system – Mostly autotrophic microalgae are used as a microbial component in the system – Utilized chemical fertilizer and organic waste to trigger phytoplankton growth – No control of the microbe community in the system – The main purpose is to provide natural food for cultured animal  Zero water discharge (ZWD) system A sustainable intensive hi-tech tank system. Maintains water quality and prevents the spreading of pathogens. Prevents nutrient-rich wastewater discharge into the environment. Utilizes the principle of microbial loops to convert toxic nitrogenous compounds (ammonium, nitrite) into lesser toxic forms (nitrate). Involves regular addition of microbial consortia to the system. Reduces water usage by partially/totally reusing the culture water. Species cultured: shrimp, prawn  Figure 2. Schematic representation of the nutrient cycle in a ZWD system Source: G. Suantika et al., 2018  1. Microbial culture tanks Separated unit facilitates easier maintenance. Tank size: 20% of culture tanks (for nitrifying bacteria/microalgae), 2.5% of culture tanks (for heterotrophic bacteria). 2. Aeration unit: aerator, silicon hose, and air stone Airflow rate Dissolved oxygen level: 4-6 ppm 3. Net covering prevents pollutant entry, reduces water evaporation and light penetration 4. Thermometer monitors daily culture temperature. 5. Feeding trays to provide daily feed. 6. CaCO3 and gravel: substrate for nitrifying bacteria attachment, buffering agent. Figure 3. Basic components of a ZWD system Source: G. Suantika et al., 2018  CONCLUSIONS Intensive farming is the best-managed aquaculture system with very high productivity. Intensive farming in high-tech tanks is highly effective in terms of water usage. Zero water discharge (ZWD) system is a type of intensive high-tech tank technology. ZWD system is based on the principle of microbial loops. ZWD system maintains water quality and prevents the spreading of pathogens REFERENCES M. A. Oyinlola, “Mariculture: perception and prospects under climate change,” Predict. Futur. Ocean. Sustain. Ocean Hum. Syst. Amidst Glob. Environ. Chang., pp. 227–239, Jan. 2019, doi: 10.1016/B978-0- 12-817945-1.00019-8. G. Suantika, M. L. Situmorang, P. Aditiawati, D. I. Astuti, F. F. N. Azizah, and H. Muhammad, “Closed Aquaculture System: Zero Water Discharge for Shrimp and Prawn Farming in Indonesia,” in Biological Resources of Water, InTech, 2018.  Advanced Aquaculture Technology Prof. Gourav Dhar Bhowmick Agricultural and Food Engineering Department, IIT Kharagpur Module 02: Technology of Closed Aquaculture Lecture 03 : Re-circulatory system  Concepts Covered Introduction to Recirculating Aquaculture System (RAS) Components of RAS Fish culture (e.g. Tilapia) using RAS Merits and demerits of RAS technology Recirculating Aquaculture System [RAS] RAS is a land-based closed system used to culture aquatic organisms. Involves rearing fish in indoor/outdoor tanks within a controlled environment. RAS involves recycling and reusing waste culture water after mechanical/ biological filtration and removal of suspended solids. RAS facilitates minimal use of land and water and involves addition of new water only to make up for evaporation losses, splash out, and that used to remove waste materials. RAS reduces environmental impacts and improves food security.  Feed used: High protein feed, with all essential minerals and vitamins. Species cultured in RAS: Baramundi/ Bhetki  Cobia  Silver/Indian Pompano  Tilapia, Pearl spot/Karimeen  Pangasius  Rainbow Trout Components of RAS  Tanks: Grow out tanks (circular cement tanks), settling tanks (for sludge), water storage (sump) tanks, overhead tanks  Pumping units  Filtration unit: Mechanical (Hydraulic) filters, Glass wool/ muslin cloth filter, Drum filter, Biofilters, UV units  Sludge/ settleable solid collector  Aeration/oxygenation unit  CO2 removal system (degasser)  Water supply system  Water testing kit  Inputs like Seed, Feed, additives/supplements Source: https://www.agrotechnomarket.com/2018/10/recirculating-aquaculture-system-ras.html  Figure 2. Schematic representation of a novel high-tech marine RAS (A) 0.3 m3 microscreen drum filter, (B) 0.4 m3 pump reservoir, (C) 0.9 m3 CO2 stripper, (D) 1.5 m3 protein skimmer, (E) 8 m3 nitrifying moving bed bioreactor (MBB), (F) 1 m3 low head oxygenator, (G) 0.6 m3 pump reservoir, (H) 0.15 m3 conical sludge collection tank, (I) 0.5 m3 sludge digestion tank, (J) 3 m3 deanammox fixed-bed up-flow biofilter, (K) 0.02 m3 biogas reactor with the gas collection. Tank water was used to backwash organic solids from the micro screen drum filter (A). Source: Y. Tal et al.,2009 Aquaculture (for e.g. Tilapia) using RAS technology Table 1: Model Technical Specifications for Tilapia culture in RAS Source: RECENT TRENDS IN AQUACULTURE, National Fisheries Development Board  Table 2: Estimated cost for Tilapia culture in RAS Source: RECENT TRENDS IN AQUACULTURE, National Fisheries Development Board Merits and demerits of RAS technology Advantages Disadvantages Low water and land requirements. Requirement of Prolonged durability of tanks and equipment uninterrupted power supply. Easy rectification of water quality parameters. High capital cost, in Reduced direct operational costs associated with comparison to ponds predator/parasite control and feed. and raceways. Potential elimination of parasite release to recipient waters. Reduced impact of adverse weather conditions, external pollution, and unfavorable temperature. High stocking density of desired species. High feed conversion ratio (≈1:1). Reduce or eliminate antibiotic, pesticide or vaccine uses. Improved health and production of the fish species.  CONCLUSIONS RAS reduces environmental impacts and improves food security. RAS facilitates minimal use of land and water. Reduces utilization of therapeutants. Facilitates high food conversion ratio and production rates Most of the fish species can be reared using RAS technology  TAKEAWAY Recirculating Aquaculture System (RAS) is a high-tech intensive closed aquaculture system. RAS:-  Reduces environmental impacts  improves food security  involves minimal use of land and water  reduces utilization of therapeutants  facilitates high feed conversion ratio (≈1:1) REFERENCES Naylor, R.L., Hardy, R.W., Buschmann, A.H. et al. A 20-year retrospective review of global aquaculture. Nature 591, 551–563 (2021). https://doi.org/10.1038/s41586-021-03308-6 Y. Tal, H. J. Schreier, K. R. Sowers, J. D. Stubblefield, A. R. Place, and Y. Zohar, “Environmentally sustainable land-based marine aquaculture,” Aquaculture, vol. 286, no. 1–2, pp. 28–35, Jan. 2009, doi: 10.1016/J.AQUACULTURE.2008.08.043. A. Jena, P. Biswas, and H. Saha, “Advanced Farming Systems in Aquaculture: Strategies To Enhance the Production,” Innov. Farming, vol. 1, no. 1, pp. 84–89, 2017, [Online]. Available: https://www.researchgate.net/publication/316191741_ADVANCED_FARMING_SYSTEMS_IN_A QUACULTURE_STRATEGIES_TO_ENHANCE_THE_PRODUCTION. https://nfdb.gov.in/PDF/06_Ras%20Booklet%20Eng.pdf  Advanced Aquaculture Technology Prof. Gourav Dhar Bhowmick Agricultural and Food Engineering Department, IIT Kharagpur Module 02: Technology of Closed Aquaculture Lecture 04 : Flow-through system Concepts Covered Introduction to flow-through systems Types of flow-through systems:-  Conventional flow-through systems  Intensive flow-through systems Merits and demerits of flow-through systems  Introduction to flow-through systems A type of intensive land-based aquaculture. Involves rearing fishes at high stocking densities in long and narrow ponds or tanks. Requires abundant continuous water flow. Facilitates high degree of control over the environment of the species to be cultured Flow-through systems are the most common facility for trout culture  Continuous flow of water ensures proper oxygenation and also flushes out the metabolic wastes. Tanks for flow-through systems are usually of:- Shape: rectangular Material: reinforced concrete, earth with inner surface covered with plastic, plastic, metal or wood. Based on water supply there are two types of flow-through systems: 1. Conventional Flow-Through Systems 2. Intensive Flow-Through Systems  Figure 1: Schematic representation of a flow-through tank. WS: water sampling; MWS: make up water sampling; INF: inflow; OUF: outflow; SD: sludge discharge; SDS: sludge discharge sampling. Source: https://www.researchgate.net/publication/311805952_Improving_sustainability_of_striped_catfish_Pangasianodon_hypophthalmus_farming_in_the_Mekong_De lta_Vietnam_through_recirculation_technology. Conventional flow-through systems (CFTs) In a CFT, the O2 requirement of the fish is delivered by the inflow water. Flow rate of water required for oxygenation > flow rate required to flush out the metabolic wastes. O2 requirement of the fish becomes the critical factor for water flow rate calculations and is calculated as follows:- 𝑄 𝑟 q=𝑊=𝐶 𝑠 −𝐶 where, q= specific flow rate; Q = actual water flow (mh-1); W = actual mass of fish in the tank (kg); Cs = DO concentration at saturation level (gm-3); C = allowable minimum DO concentration (gm-3); r = specific oxygen consumption of the fish (gh-1kg-1) Intensive flow-through systems (IFTs) Developed recently with the primary aim of increasing the stocking density or decreasing the water flow. O2 requirement of the fish is provided by oxygenating the inflow water. Flow rate needed to flush out the metabolic wastes becomes the critical factor for water flow rate calculations. Raceways are a type of intensive flow through systems. Merits and demerits of Flow-through Culture Advantages Disadvantages Continuous flow maintains O2 level Requirement of large volumes of and temperature and removes CO2 water. and nitrogenous wastes Inability of self-cleaning Facilitates higher production levels Possess cleaning difficulties. (up to 1,000x more than pond culture) Requirement of high DO level maintenance. Facilitates discharge of effluents with lower concentrations of Cultured fishes consume more solids/nutrients. food due to requirement of high energy for swimming. Relatively easier feeding, grading and harvesting CONCLUSIONS Flow through systems are a type of intensive land-based aquaculture These systems are characterized by requirement of abundant continuous water flow. Major disadvantage of such systems involve requirement of high volumes of water and absence of self-cleaning abilities. TAKEAWAY Flow through systems are a type of intensive land-based aquaculture They require abundant continuous water flow. They facilitate higher production than traditional ponds They possess cleaning difficulties; lacks self-cleaning ability REFERENCES https://www.researchgate.net/publication/311805952_Improving_sustainability_of_striped_catfish_Pa ngasianodon_hypophthalmus_farming_in_the_Mekong_Delta_Vietnam_through_recirculation_technol ogy [accessed Apr 04 2022]. Food and Agriculture organization of the united nations, Chapter 13 Deign and Construction of Raceways and Other Flow-Through Systems [https://www.fao.org/3/x5744e/x5744e0e.htm]  Advanced Aquaculture Technology Prof. Gourav Dhar Bhowmick Agricultural and Food Engineering Department, IIT Kharagpur Module 02: Technology of Closed Aquaculture Lecture 05 : Raceway culture Concepts Covered Introduction of raceways Advantages of raceways General criteria for constructing raceways Type of raceways In-pond raceway system  Introduction An intensive flow-through system. Requires continuous flow of water for high-density fish production. Trout, tilapia, and catfish are commonly cultured in raceways Figure 1: Raceway culture of Tilapia Facilitates maintenance of water quality. (Source: El-Sayed et al., 2020) Ideal for rural areas where irrigation canals are available. Often built on sloping terrain in series to enable falling of water from the tail of one unit to the head of the adjacent unit, facilitating oxygenation. Self-cleaning is not always possible in such systems. Did you know?? As maintenance of a minimum velocity is necessary for self-cleaning and at such velocities small fishes fail to swim rapidly to remain stationery, so self-cleaning is not always possible in raceways.  Advantages of raceways Continuous water flow minimizes concentration of metabolites in hatcheries. Absence of DO depletion. Flowing water system forces fish to exercise. Better survival rate for hatchery fishes when reared in raceways before stocking. Facilitates visual observation of fish movements in shallow raceways, enabling reduction in management problems. Facilitates convenient feeding. In case of disease outbreak, fish can be treated, before flushing out the raceway. General criteria for constructing raceways Maintenance of a plug/laminar flow, to avoid settling of solids at the bottom. Facility must provide protection from outside pollutants, flooding and sedimentation. Since raceways involve flow of large quantities of water, making the pumping system a critical factor in their design. The mean water velocity (v) in a raceway with water flowing from one end can be expressed as:- 𝑏. 𝑑. 𝐿 𝑣= 𝑆. 𝑞 = 𝐿. 𝑆. 𝑞 (𝑚ℎ−1 ) 𝑏. 𝑑 b = breadth of tank (m); d = depth of tank water (m); L = length of tank (m); S = fish stocking density (kgm-3); q = specific flow rate (m3kg-1h-1) Did you know?? Appropriate plug flow is hard to achieve in raceways due to stationery boundary layer formation at the raceway walls  Water velocity should be maintained to:  Reduce stress and energy wastage of the fish and  Avoid wash-away of the supplied food particles.  Keep the generated waste in a suspended condition. Material used for construction: concrete, earth with inner plastic cover (for large outdoor raceways), plastic, metal, or wood.  Schematic top view of the 100 m3 raceway. Figure 2: Schematic (top view) of a 40m3 raceway with support systems Source: Samocha et al., 2019  Type of raceways There are generally three types of raceways: linear, tank and mixed-cell raceways 1. Linear channel raceways Has separate inlets and outlets Made of either a) concrete blocks or b) earthen channels with trapezoidal/parabolic cross section. Should have a bottom grade of at least 0.5 ft. per 100 ft.  Length of these raceways are determined based on site topography along with the need for re-aeration.  Width is determined on the basis of available water supply, operation/maintenance needs and available harvesting equipment. 2. Circular/rectangular/oval tanks  Nozzles are used as inlets enabling a rotary circulation within the tank, whereas a standpipe/bottom drain is connected at the tank center for discharge.  Nozzles are located above the surface of water for aeration  Made of concrete, metal or fiberglass  Constructed at sites having accessible water supply, adequate management personnel, feed and harvesting equipment. 3. Mixed-cell raceways (MCRs)  Developed by Watten et al. 2000.  Combines the characteristics of linear channel raceways and circular tanks within a single vessel.  Facilitates rapid solid removal, maintenance Figure 3: A Mixed-Cell Raceway of uniform water quality, easier maintenance made using structural lumber and covered by an HDPE liner. and husbandry.  Presence of vertical jet port manifolds in MCRs (at sidewalls) converts linear raceways into a series of adjacent mixed-cells each having a hydraulically independent flow regime. Source: Labatut et al., 2007  A bottom-center drain forces each cell to act as an individual circular tank. Figure 4. Vertical discharge (jet port) manifolds present along the sidewalls of the MCR. On the far left, a single-sided manifold composed of five nozzles directed across the width of the raceway. Middle and far right pictures show the double-sided manifolds composed of ten nozzles directed tangentially to the raceway wall. Source: Labatut et al., 2007  Table 1: Design, operational and performance parameters of a MCR Characteristic​ Value​ MCR water depth (m)​ 1​ MCR volume (m3)​ 91​ MCR total flow rate (m3/h)​ 152​ MCR water exchange rate (volumes/h)​ 1.7​ Cell characteristic length (m)​ 5.5​ Cell diameter-to-depth ratio (m)​ 5.5:1​ Bottom-center flow (%)​ 15​ Surface loading rate at the bottom-center drain (L/min m2 cell floor)​ 4.2​ Nozzle discharge velocity, i.e., jet velocity (m/s)​ 4.8​ Nozzle diameter (mm)​ 15​ Jet port manifold hydraulic head (m)​ 1.36​ MCR power requirements (W/m3)​ 8.9​ Source: Labatut et al., 2007 In-pond raceway system (IPRS) A highly innovative raceway system for increasing the productivity of subtropical fish species like tilapia within existing fish ponds. Involves flowing of aerated water from one end while removal of fish wastes/uneaten feeds from the other end. The ultimate idea behind this system involves the continuous mixing and aeration of water. Solid wastes are collected 2-3 times per day using a vacuum pump.  Constructed using concrete rectangular cells (2-3 per pond) built parallel to each other About 3%-5% of the pond size is used for the raceway area. Figure 5: Tilapia culture in a IPRS made of concrete rectangular cells Source: El-Sayed et al., 2020b  Advantages of IPRS over traditional pond culture:- Increased net yield and growth rates. Improved feed utilization, thus, more reduction in feed costs. Improved product quality. Reduced infections/disease and mortality rates. Improved water remediation Reduced environmental impacts Conservation of water due to recycling and reusing  Conditions required for optimal operation of IPRS Stocked fish should be clean and healthy. Feeds used should be of top quality. Pond water should be kept in a well mixed condition. Continuous removal of solid wastes. Proper maintenance of equipment. CONCLUSIONS Requires continuous flow of water for high-density fish production. Self-cleaning is not always possible Pumping systems are a critical factor in the design of raceways. Requires maintenance of a plug/laminar flow, to avoid settling of solids at the bottom Raceways facilitate increased net yield and growth rates. Provides improved feed utilization, and thus, more reduction in feed costs. TAKEAWAY Raceway is a intensive flow-through system that supports high- density fish production. Involves continuous flow of water Self-cleaning is not always possible There are three type of raceways namely linear, tank and mixed-cell raceways In-pond raceway system is used for increasing the productivity of subtropical fish species like tilapia within existing fish ponds. REFERENCES El-Sayed, A.-F. M. (2020). Intensive culture. Tilapia Culture, 103–134. https://doi.org/10.1016/B978-0-12- 816509-6.00006-9 Samocha, T. M., Prangnell, D. I., & Castro, L. F. (2019). Site Selection and Production System Requirements. Sustainable Biofloc Systems for Marine Shrimp, 59–117. https://doi.org/10.1016/B978-0-12-818040-2.00005- 8 Chandra Mal, B. (2021). Raceways and tanks. Aquacultural Facilities and Equipment, 239–268. https://doi.org/10.1016/B978-0-323-85691-1.00009-X Natural Resources Conservation Service, USDA. https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs143_025682.pdf Labatut, R. A., Ebeling, J. M., Bhaskaran, R., & Timmons, M. B. (2007). Hydrodynamics of a Large-scale Mixed- Cell Raceway (MCR): Experimental studies. Aquacultural Engineering, 37(2), 132–143. https://doi.org/10.1016/J.AQUAENG.2007.04.001 El-Sayed, A.-F. M. (2020b). Technological innovations. Tilapia Culture, 297–328. https://doi.org/10.1016/B978-0-12-816509-6.00013-6