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PRINCIPLES OF AQUACULTURE (AKU3201). Other aquaculture systems. Method of culture. Ponds Cages Raceway Recirculating Others – tanks, strings, rack, pisciponic. Cages. Floating or submerged units Placed in open water i.e., lake, reservoir, river, estuary, open ocean Netting to hold fish
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PRINCIPLES OF AQUACULTURE(AKU3201) Other aquaculture systems
Method of culture • Ponds • Cages • Raceway • Recirculating • Others – tanks, strings, rack, pisciponic
Cages • Floating or submerged units • Placed in open water i.e., lake, reservoir, river, estuary, open ocean • Netting to hold fish • Fed with pellet
Frame • Hold net • Stainless steel • Floatation devices
Netting • Polyethlyene, polyester wire nylon • Net size < Fish size
Depth: 1 – 2 m • Freeboard: 15-30 cm • Weightage at every side • Metal frame
Cages Advantages • Continuous flow of clean/new water • Easy harvesting • Different species in different cages • Waste, excessive feed are not accumulated in the culture system • Stocking rate can be regulated easily
Cages Disadvantages • Changes in environmental surroundings & water quality • Noxious algal bloom • Slower species growth compared to pond culture • Frequent net cleaning • Disease problem • Climate problem • Theft
Requirement • Non-polluted area • Protected/sheltered area • Low drastic salinity change • Small waves (except cage in deep sea areas)
RAS • RAS= Recirculating aquaculture systems • Water is processed to restore water quality • Recycle back to the culture tank
Suitable when: • Land or water is limited • Natural water is of poor quality • Ambient temperatures for cultured spp. are outside the range
Biofilter • Substrate on which aerobic bacteria will grow • Bacteria change the form of nitrogen from toxic to non-toxic form • Toxic = Ammonia (NH3) • NH3 -> NO2 (Nitrosomonas) • NO2 -> NO3 (Nitrobacter)
Flow-through • Water continuously flow
Raceway • Water continuously flow
Strings • Semi-controlled • Boat & strings/rope • Marine
String/line • Bivalve & seaweed
Pisciponic • Culture synergy of fish & plant • Maximum use of water, soil, space & increase production & income • Reduce nutrient need 75-100% • Minimum aquaculture waste • Japanese salad, kailan, tomato • Baung, keli, tilapia • Tilapia the best
Stake • Semi controlled & marine • Clams/abalone/oysters
Tray/Raft • Semi-controlled & marine • Bivalve (oyster/clams)
Pen (Crab) • Introduced by Jabatan Pertanian Sarawak • Application – SEA & Australia • Cage constructed in mangrove area • Minimum cutting (20%) & sustain forest area • Ketam nipah Scylla serrata, S. olivacea, S. tranquebarica
Sea Ranching • Selection of wild broodstock & artificial production of juveniles which are released into the natural environment then harvest • Semi-controlled • Species: Salmon, lobster
Seacage cultivator • Combination of raft, line and cage • Facility: • Wave resistant • Ease of handling • Production per area is high • Semi control • Commercial species: abalone, sea cucumber
Bioreactor • Culture of microalga for health product and live feed for fish, crustacean and molluscan larvae • Chlorella, Spirullina
IMTA • Integrated multi-trophic aquaculture • Integration between seaweed and other aquatic organisms