AGE 308 — Fish Farming and Management: Lecture Note

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This is the complete lecture note for AGE 308 Fish Farming and Management. You can read it online below, open it in the full viewer, or download the PDF for offline study. It pairs with the course's video lectures, so you can read and watch together.

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AGE la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS

AGE la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Course code: AGE 308 Course title: Fish Farming and Management Course credit load: 2 Units Series 1: Foundations of Fisheries and Aquaculture • Part 1.1: Definitions and Scope of Fisheries and Aquaculture o Sub Part 1.1.1: Definitions and key concepts o Sub Part 1.1.2: Scope and branches of fisheries science o Sub Part 1.1.3: Differences between capture fisheries and aquaculture • Part 1.2: Importance of Fisheries and Aquaculture in Nigeria o Sub Part 1.2.1: Nutritional and food security importance o Sub Part 1.2.2: Economic and livelihood importance o Sub Part 1.2.3: The fish industry in Nigeria • Part 1.3: Fisheries Resources of West Africa and Nigeria o Sub Part 1.3.1: Freshwater fisheries resources o Sub Part 1.3.2: Marine and coastal fisheries resources o Sub Part 1.3.3: Important fish species of Nigeria • Part 1.4: Principles and Policy Framework of Fisheries Management o Sub Part 1.4.1: Fundamental principles of fisheries management o Sub Part 1.4.2: Fisheries legislation and policy in Nigeria o Sub Part 1.4.3: International fisheries agreements and conventions

AGE la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Introduction Fish is the most important single source of animal protein in the Nigerian diet, supplying approximately 40 per cent of total animal protein consumed by the population. Yet Nigeria imports hundreds of thousands of tonnes of fish annually to bridge the gap between domestic production and demand, at a foreign exchange cost that runs into billions of naira. Understanding the foundations of fisheries science and aquaculture is the essential starting point for addressing this deficit and for equipping students with the knowledge to contribute to national food security through productive fish farming and responsible resource management. This Series introduces the definitions, scope, and branches of fisheries science and aquaculture, distinguishes between capture fisheries and aquaculture, explains the nutritional, economic, and industrial importance of fisheries in Nigeria, surveys the freshwater and marine fisheries resources of West Africa and Nigeria, and covers the fundamental principles and policy framework of fisheries management. All subsequent Series build on these foundations. Series Learning Outcomes Upon completing this Series, you should be able to: • SLO 1.1 define fisheries and aquaculture and explain the key concepts of each (Linked to Part 1.1), • SLO 1.2 describe the scope and main branches of fisheries science (Linked to Part 1.1), • SLO 1.3 distinguish between capture fisheries and aquaculture and explain the advantages of each (Linked to Part 1.1), • SLO 1.4 explain the nutritional importance of fish in Nigeria and describe its contribution to food security (Linked to Part 1.2), • SLO 1.5 describe the economic importance of fisheries and the structure of the fish industry in Nigeria (Linked to Part 1.2), • SLO 1.6 identify the major freshwater and marine fisheries resources of West Africa and Nigeria (Linked to Part 1.3),

AGE la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS • SLO 1.7 name the important fish species of Nigeria and state their habitat, distribution, and economic value (Linked to Part 1.3), and • SLO 1.8 explain the fundamental principles and policy framework of fisheries management in Nigeria (Linked to Part 1.4). 1.1 Definitions and Scope of Fisheries and Aquaculture 1.1.1 Definitions and key concepts Fisheries is the science and practice concerned with the harvesting, management, and conservation of fish and other aquatic organisms from their natural environments (oceans, rivers, lakes, and estuaries). It encompasses the biological study of fish populations, the technology of fish capture, and the economic and social dimensions of fishing communities. Aquaculture is the controlled cultivation of aquatic organisms (fish, shellfish, crustaceans, molluscs, and aquatic plants) in freshwater, brackish water, or marine environments, analogous to agriculture on land; it involves deliberate intervention in the rearing process to increase production above what natural environments would yield. Related key concepts include: fish stock (a population of fish of one species in a defined area that is managed as a unit); sustainable yield (the quantity of fish that can be harvested repeatedly over time without depleting the stock); maximum sustainable yield (MSY, the largest average catch that can be harvested from a stock under prevailing environmental conditions on a sustainable basis); by-catch (non-target organisms unintentionally caught during fishing operations); and aquatic biodiversity (the variety of species, genetic diversity, and ecosystem diversity in aquatic environments). These concepts underpin all subsequent topics in the course. Fill in the blank: Aquaculture is the controlled cultivation of aquatic organisms in fresh, brackish, or marine water, analogous to agriculture on land; it involves deliberate ________ in the rearing process to increase production above natural yields.

AGE la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS 1.1.2 Scope and branches of fisheries science Fisheries science is multidisciplinary, drawing on biology, ecology, oceanography, limnology, engineering, economics, and social science. The major branches are: fish biology (anatomy, physiology, behaviour, and life history of fish); fisheries ecology (the interaction of fish populations with their biotic and abiotic environment); fisheries stock assessment (the quantitative evaluation of fish stock size, growth, mortality, and reproductive rate to support management decisions); fishing technology (the design and operation of fishing gear, vessels, and navigation systems); aquaculture (controlled fish and shellfish rearing); fish processing and preservation (methods for maintaining fish quality from catch to consumer); and fisheries economics and management (economic analysis of fishing industries and the governance of fisheries resources). In Nigeria, fisheries science is taught and practised in university departments of aquaculture and fisheries management, at the Nigerian Institute for Oceanography and Marine Research (NIOMR) in Lagos, at the National Institute for Freshwater Fisheries Research (NIFFR) in New Bussa, and at several state fisheries departments. The Federal Department of Fisheries (FDF) under the Federal Ministry of Agriculture and Rural Development coordinates national fisheries policy, stock assessment, and extension services. Fill in the blank: The two major national research institutes for fisheries in Nigeria are NIOMR (marine research) in Lagos and ________ (freshwater fisheries research) in New Bussa. 1.1.3 Differences between capture fisheries and aquaculture Capture fisheries harvest fish from their natural habitats using nets, traps, lines, and other fishing gear. The fish are wild, the breeder does not control reproduction or feeding, and the quantity that can be harvested is limited by the natural productivity of the water body. In Nigeria, capture fisheries operate on the Atlantic Ocean coast, in inland rivers (Niger, Benue, Cross River, Sokoto-Rima), and in natural and man-made lakes (Lake Chad, Kainji, Jebba, Shiroro, and Tiga). Capture fisheries production in Nigeria is estimated at approximately 600,000 to 800,000 metric tonnes per year but has been declining due to overfishing and environmental degradation.

AGE la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Aquaculture grows fish under controlled conditions in ponds, tanks, cages, or raceways. The farmer controls stocking density, feeding, water quality, and reproduction, enabling yields far higher than natural water bodies. Aquaculture has been the fastest-growing food production sector globally for three decades, now supplying approximately 50 per cent of world fish consumed. In Nigeria, aquaculture (primarily catfish and tilapia farming) has expanded rapidly since the 1990s and currently produces approximately 300,000 to 400,000 metric tonnes per year, still far short of national demand. The deficit is bridged by imports, predominantly frozen mackerel (Scomber japonicus) and herrings. Fill in the blank: Nigeria's capture fisheries produce approximately 600,000 to 800,000 metric tonnes per year but have been declining due to ________ and environmental degradation; aquaculture produces approximately 300,000 to 400,000 metric tonnes per year. Aspect Capture Fisheries Aquaculture Environment Natural water bodies (rivers, lakes, reservoirs, coastal waters) Artificial ponds, tanks, cages, controlled systems Production Control Very limited; dependent on natural stock and ecosystem High; stocking density, water quality, and management controlled Feeding Natural food sources (plankton, aquatic plants, smaller fish) Supplementary or complete formulated feeds provided Reproduction Natural spawning in wild habitats Induced breeding, controlled spawning, hatchery management Nigerian Species Tilapia, catfish, bonga, croaker African catfish (Clarias gariepinus), tilapia, Heterobranchus spp. Yield Variable, often declining due to overfishing Predictable, higher per unit area under good management Sustainability Threatened by overfishing, pollution, habitat loss More sustainable if managed well, but requires inputs and monitoring Table 1.1: Comparison of capture fisheries and aquaculture Pilot questions 1.1 1. Define fisheries and aquaculture and explain how they differ.

AGE la-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS 2. Define maximum sustainable yield (MSY) and explain its importance in fisheries management. 3. Name four branches of fisheries science and briefly describe each. 4. State two national institutions responsible for fisheries research in Nigeria and their locations. 5. State three advantages of aquaculture over capture fisheries for Nigerian food production. 1.2 Importance of Fisheries and Aquaculture in Nigeria 1.2.1 Nutritional and food security importance Fish provides high-quality animal protein, essential fatty acids (especially omega-3 polyunsaturated fatty acids, EPA and DHA), vitamins (A, D, B12), and minerals (iodine,

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