Overview
This lecture covers the history, types, and common methods of aquaculture practiced in freshwater, brackish, and marine environments, with emphasis on specific culture systems.
Introduction to Aquaculture
- Aquaculture is the farming of aquatic organisms and has been practiced for about 4,000 years, originating in China.
- Initial practices involved trapping and holding wild fish, gradually evolving into husbandry methods.
Types of Aquaculture Environments
- Aquaculture can occur in freshwater, brackish water, or marine (saltwater) environments.
- Organisms cultured include fish, shellfish, and seaweeds.
Marine Aquaculture (Mariculture) Methods
- Floating cages are used for fish, prawns, and lobsters.
- Racks, rafts, ropes, poles, and longlines are used for culturing mollusks and seaweed.
- Artificial reefs are placed to enhance marine habitats.
Cage and Raft Culture
- Cage culture uses floating frames with nets in lakes, rivers, or seas for intensive fish rearing.
- Types of cages: fixed, submerged, floating, and movable cages.
- Raft culture uses floating bamboo/wooden frames to grow shellfish or seaweed; rafts can be arranged in single units or blocks.
Other Marine Culture Methods
- Rack culture uses steel racks in intertidal zones for mollusks.
- Pole (stake) culture uses rows of wooden poles in muddy areas.
- Longline culture uses suspended ropes anchored at both ends for mollusks.
Brackish Water Culture
- Brackish water, rich in oxygen and plankton, supports the culture of fish, crabs, and shellfish in tidal ponds, cages, and racks.
- Mangrove areas are used to culture species such as the mangrove crab.
- Pen culture combines features of pond and cage culture for fish.
Freshwater Aquaculture Methods
- Freshwater culture uses ponds, reservoirs, lakes, and rivers to raise fish, shrimp, crab, and aquatic plants.
- Composite fish culture involves raising multiple fish species with different food habits together to maximize resource use.
- Monosex culture focuses on raising either all-male or all-female populations for improved growth rates.
- Monoculture (moniecies culture) involves culturing only one species, such as tilapia.
Specialized Culture Techniques
- Air-breathing fish are cultured in shallow, low-oxygen water bodies.
- Predator-prey culture mixes predator fish with prey species in one habitat.
Key Terms & Definitions
- Aquaculture — farming of aquatic organisms in controlled environments.
- Mariculture — aquaculture practiced in marine or ocean environments.
- Brackish Water — water with moderate salinity, between freshwater and seawater.
- Cage Culture — raising fish in netted enclosures in open water.
- Raft Culture — growing shellfish/seaweed on floating frames.
- Composite Fish Culture — raising multiple fish species with different food habits in one pond.
- Monosex Culture — culturing only male or only female fish populations.
- Monoculture (Moniecies Culture) — culturing a single species in one system.
Action Items / Next Steps
- Review diagrams of cage, raft, and pen culture systems.
- Prepare notes on advantages and limitations of each aquaculture method for next class.