Aquaculture & Fisheries Cheatsheet

Cheatsheet Content

Introduction to Aquaculture and Fisheries Definition of Fisheries: Any body of water with which humans interact for fishing (sport, recreational), or obtaining ornamental fish or fish products (e.g., fish oil). Definition of Aquaculture: Culturing of aquatic biota in fresh, sea, or brackish water by humans as an economic activity. $\frac{3}{4}$ of world (over 70%) consists of water. Less than 3% is fresh water. Every aquatic ecosystem has potential to produce protein-rich fish as food. Importance of Fish Food Source: Cheapest protein, especially for Asians. Commercially available in various forms (fresh, frozen, dried, canned, etc.). Consumption not restricted by cultural taboos. High dressing percentage (70% edible matter). Nutritional Value: Radically improves biological value of protein. Healthy food, especially for convalescing people. Low LDL, high HDL. Essential Amino Acids: lysine, methionine. Omega-3 fatty acids: eicosapentaenoic (EPA) and docosahexaenoic (DHA). High energy value: 50-160 Kcal/100g. Good source of Ca, Fe, Zn, I$_2$, and vitamins A, B$_{12}$, D. Economic Impact: Generates jobs, income, and wealth. By-products: (e.g., Shark fin rays). Integrated System Component: Part of larger agricultural systems. Recreational Purpose: Pleasure, hobby (e.g., ornamental fish). Research Purposes: (e.g., Zebrafish, mussels). Pest/Weed Controller: Goldfish, bass, guppies, catfish control mosquitoes. Therapeutic Use: Fish Pedicure/Fish Spa/Fish Therapy. Characteristics for Aquaculture Species Cold-blooded animals: Less energy for thermoregulation, more for growth. 3D Rearing Space: All layers of a pond/reservoir can be utilized. Polyculture is common: Upper layer: Bighead carp, Catla, Grass carp Middle layer: Rohu, Silver carp Bottom layer: Common carp, Catfish High feed conversion efficiency. High carcass recovery percentage (edible portion). High diversity: Many species adapted to different ecosystems, food habits, temperatures. High growth rate. Life cycle control: Must be completely and easily understood. Tolerance for environmental conditions. Lower level of food chain. Low susceptibility to disease. Tolerance to over-crowding. Components of Fisheries and Aquaculture Sector Inland Marine Capture Freshwater Capture Marine Capture Culture Freshwater Culture Brackish Water Culture Challenges in Fisheries Sector Overfishing Illegal fishing Climate change Pollution Urbanization Impact of Invasive Species Challenges in Aquaculture High risk due to piscivorous fish, birds, and mammals. Pest and disease problems. Lack of technology and skills to harvest fish. Unavailability of infrastructure facilities. Unavailability of suitable preserving and processing technology. Lack of sufficient research. Inefficient management. Why is Aquaculture Important? Increasing population. Failing agriculture (failure to meet protein demand, low return of energy invested). Failing fishery (limited sea resources, overfishing, high energy for wild catch). Consumer demand for consistent supply of quality fish at the right price. Fish play a major role in protein supply. Fishery Potentials of Sri Lanka 1. Aquatic Resources Total coastline: 1,730 km$^2$ EEZ cover: 500,000 km$^2$ Continental shelf: 30,000 km$^2$ Inland waters: 2,900 km$^2$ (Lakes, Rivers, Streams, Ponds, Canals, Dams, other land-locked waters) Fisheries sector provides direct/indirect employment for $\sim$583,000 people and livelihoods for 2.7 million coastal communities. Provides $>60\%$ of animal protein requirement for the country. 2. Fishing Vessels and Gears Approximately 28,000 fishing crafts operated. $87\%$ operated in coastal waters. Traditional non-motorized crafts ($55\%$): Outrigger canoes, Wooden dugouts (Orus), Log rafts (Wallam, Theppam, Kattumarans). Fiberglass Reinforced Plastic (FRP) boats ($32\%$): 18 feet with outboard engine, some 28-32 feet with inboard engine. 3. Diversity of Fish Inshore areas (up to 5 km): Small Pelagics: Sardinella, Herrings, Anchovies. Small Demersals: Ponyfish (Karalla), Snappers. Beyond inshore areas: Medium-size Pelagics: Flying fish, Needlefish, some tuna. Large Demersals: Groupers, Snappers, Breams. Non-finfish: Lobsters, crabs, shrimps, sea cucumbers. Inland Fish Production & Species (2010-2014) Species 2010 (MT) 2014 (MT) Tilapia 850 46610 Brackish water shrimp 3480 5150 Freshwater prawn 45 460 Common carp 807 836 Catla 1280 2514 Rohu 720 1272 Mrigal Na 239 Bighead carp 285 158 Silver carp 205 78 Grass carp Na 9 Labeo sp. 185 78 Hirikanaya Na 580 Snakehead Na 2230 Sea bass 10 18 Sea cucumber Na 213 Mud crab 18 10 Other wild fish Na 5820 Important Indigenous Inland Fish Species Snakehead, Pena walaya, Ankuta, Stinging catfish (Hunga), Spine eel (Teliya), Eels, Mal koraliya, Rasbora dandia, Puntius (Pethiya), Smaller carp (Podi pethiya), Katu pethiya, Hiri kanaya, Dankola pethiya, Air breather (Kawaiya), Giant snakehead (Magura), Freshwater shark (Walaya), Tank sardine (Wewa salaya). High necessity to introduce high-performing species to Sri Lankan water bodies. Sri Lanka has a low number of indigenous freshwater fish and 18 exotic species. Introduced Exotic Species Chinese Carps (1976): Grass Carp ( Ctenopharyngodon idellus ), Silver Carp ( Hypophthalmichthys molitrix ), Bighead Carp ( Aristichthys nobilis ). Indian Carps (1981): Catla ( Catla catla ), Rohu ( Labeo rohita ), Mrigal ( Cirrhinus mrigala ). Tilapia: 1952: Oreochromis mossambicus 1969: Tilapia rendali (red tilapia), Oreochromis niloticus (Nile tilapia) 2001: GIFT Tilapia (Genetically Improved Farm Tilapia) 4. Authorities Related to Fisheries in Sri Lanka Ministry of Fisheries NAQDA (National Aquaculture Development Authority): Entrusted with developing commercial aquaculture and extension activities. NARA (National Aquatic Resources Research and Development Agency): Principal national research institution for aquatic resources. Ceylon Fisheries Corporation Ceylon Fishery Harbours Corporation CEY-NOR Foundation NIFNE (National Institute of Fisheries & Nautical Engineering / Ocean University): In charge of education and training. Identification of Aquatic Biota Aquatic Biota: Organisms living in or depending on the aquatic environment. Types: Microorganism, Aquatic Plants/Algae, Aquatic Invertebrate, Aquatic Vertebrate. Macrofauna, Macroflora, Microfauna, Microflora. Aquatic Microorganisms Microscopic organisms (unicellular or cell clusters), visible under microscope. Prokaryotes: Bacteria, Archaea, Cyanobacteria. Eukaryotes (Protists): Protozoa (animal-like): Paramecium, Amoeba. Protophyta (plant-like, autotrophic): Diatom, green, red, brown algae (e.g., Chlamydomonas, Spirogyra). Molds (fungus-like): Water mold, slime mold. Aquatic Plants / Macrophytes Plants adapted to live in an aquatic environment. Functions: Provide cover for fish, substrate for invertebrates, produce oxygen, act as food for some fish. Classification of Aquatic Plants Based on Water Source: Marine, Brackish water, Freshwater. Marine Aquatic Plants: Seagrasses: Flowering plants on ocean floors. Maintain water quality (filter nutrients), prevent soil erosion, protect juvenile fish, provide habitat/food for various organisms, absorb carbon (35x faster than rainforests). Marine Algae (Seaweeds): Important primary producers. Edible (traditional Asian food), novel source for bioactive properties (antiallergy, anticancer, anti-inflammatory, antiobesity, antioxidant, antithrombosis). Seaweed aquaculture is $51.3\%$ of global mariculture production (e.g., Nori, Wakame). Based on Biotypes (Aquatic Macrophytes): Free floating: Azolla, Water lettuce, Duckweed. Rooted submerged: Hydrilla, Vallisneria, Potamogeton. Submerged free: Ceratophyllum, Utricularia. Emergent: Limnophylla heterophylla, Typha, Sagittaria. Submerged with floating leaves: Nymphaea, Nelumbium, Marsilea. Amphiphytes. Zonation in Lakes and Ponds Littoral Zone: Shore area. Limnetic Zone: Open water area. Euphotic Zone (Epilimnion): Warm water, photic zone (receives sunlight). Upper portion of limnetic zone. Profundal Zone (Hypolimnion): Cold water, aphotic zone. Below euphotic zone, little oxygen. Benthic Zone: Bottom of pond/lake, organic sediments and soil. Aquatic Organism Movement & Habitat Groups Plankton: Tiny organisms, cannot move on their own, live in photic zone. Phytoplankton: Bacteria and algae, use sunlight for food. Zooplankton: Animals that feed on phytoplankton. Nekton: Aquatic animals that can move by swimming. Live in photic or aphotic zone, feed on plankton or other nekton (e.g., Fish, squid, octopus, sharks, marine mammals). Benthos: Aquatic organisms that crawl in sediments at the bottom. Many are decomposers. Aquatic Invertebrates Small organisms without backbones, found in freshwater and saltwater. Porifera, Cnidaria, Arthropods, Molluscs, Echinoderms. Food Fish Classification Fish: Fin Fish: Marine water fish, Brackish water fish, Freshwater fish. Shell Fish (Invertebrates): Mollusks: Bivalve (Mussels), Univalve (Abalone, Sea Snail, Conch), Cephalopod (Squid, Octopus). Crustaceans: (Shrimp, Prawns, Crabs, Lobsters). Echinoderms: (Starfish, Sea Urchin, Sea Cucumber). Biology of Aquaculture Species Habitat Type Categorization of Saltwater Fish by Habitats: Coastal fish, Deep sea fish, Pelagic fish, Demersal fish, Coral reef fish. Freshwater Habitats: Lentic Ecosystems: Standing water bodies (Lakes, ponds, swamps). Lotic Ecosystems: Flowing water bodies (Rivers, canals, streams). Brackish Water Fish Species (Life Cycle Pattern): Allochthonous from sea, Allochthonous from fresh water. Major Production Systems (Brackish Water): Lagoons, Estuaries, Mangroves. Fish Morphology External Anatomy: Nares (Nostrils), Mouth, Eye, Operculum (Gill Cover), Pectoral Fins, Pelvic Fins, Spiny Dorsal Fin, Soft Dorsal Fin, Scales, Vent, Anal Fin, Lateral Line, Peduncle, Caudal (Tail) Fin. Internal Anatomy: Brain, Spinal Cord, Muscles, Stomach, Swim Bladder, Kidney, Eggs, Urinary Bladder, Gills, Heart, Liver, Spleen, Gall Bladder, Intestines, Vent. Caudal Fin Shapes Rounded, Truncate, Emarginate, Forked, Lunate. Scale Types Ctenoid (Bass), Cycloid (Salmon), Ganoid (Gar), Placoid (Shark). Mouth Types (based on water layer utilization) Final / Terminal Mouth Upper / Superior Mouth Bottom / Inferior Mouth Body Shapes Fusiform (Tuna): Fast-swimming in open water. Compressiform (Tautog): Quick speed for short distances. Depressiform (Skate): Swims like a flying bird. Filiform (Pipefish): Slithers through water like a snake. Body Coloration Counter Shading Cryptic Coloration Disruptive Coloration Reproductive Biology of Aquaculture Species Reproduction: Creation of new individuals from existing ones. Asexual Reproduction: Budding (Hydra) Gemmules (Internal Buds, Sponges) Fragmentation (Planaria) Regeneration (Starfish) Parthenogenesis (Rotifers, Cladocera, Copepoda) Sexual Reproduction: Fusion (fertilization) of two haploid gametes (sperm and egg) to form a diploid zygote. Basic mechanism is MEIOSIS. Reproduction Modes Oviparity: Lay undeveloped eggs. Broadcast spawning. External fertilization. Release thousands to millions of tiny eggs into water column. Semelparous species: Single spawning event (salmon). Iteroparous species: Several breeding events. Annual single-spawners (catfishes). Annual multiple-spawners (cichlids, Tilapia). Ovoviviparity: Internal development, no direct nourishment from mother (fertilized eggs carried). Larval birth (guppy, molly, platies, sword tails). Viviparity: Internal development, direct maternal nourishment (placental). Fully advanced at birth, live-bearing (sharks, some bony fish, dolphins). Mating Systems Promiscuous: Both sexes have multiple partners (mass spawning events, sailfin fish). Polygamous: One sex has multiple partners. Polygyny: Male fish has multiple partners (common, e.g., wrasses, harem formation). Polyandry: Females have multiple partners (uncommon). Monogamous: Have one partner (butterfly fishes, angler fishes, mouth brooders). Genders Gonochoristic: Sex is fixed, one sex (most fishes). Hermaphroditic: Contain both sex organs at some point. Simultaneous: Both sexes at once (deep water fishes, hamlets). Sequential: Changes sex. Protandrous: Male into female (moray eels, sea bass). Protogynous: Female into male (most common, wrasses, parrotfishes). Sexual Strategies Female Investments (due to cost): Energy investment in eggs, migration, brooding. Male Investments: Advertisement (colors, tubercles, kypes), mate competition, nest building, territorial defense, migration, parental care, brood guarding. Salmon Kype: Hook on lower jaw of male salmon to nip and bite other males during spawning. Tubercles: Small bumps on goldfish skin, secondary sexual characteristic. Nest Building: Cichlid fish (bowers), Sergeant Majors (Abudefduf saxatilis), Lamprologus callipterus (shell nests), Fighter fish/Gourami (bubble nests), Pufferfish (sand circles). Monomorphic No visible external differences between sexes (most fishes, e.g., sea cucumber).