Aquaculture Systems Overview

Types of Aquaculture

• Different types of aquaculture exist based on hydrobiological features, the motive of farming, and special operational techniques.

Open Aquaculture Systems (OASs)

• OASs involve rearing aquatic organisms within enclosed systems in natural environments like freshwater rivers, coastal marine regions, and brackish estuaries.
• They utilize floating mesh cages anchored to the seafloor.
• Examples of organisms cultured in OASs include seabream, seabass, codfish, tilapia, salmon, and shark catfish.
• Cultured species in OASs rely on a fishmeal diet.
• Stick, rack, and rope-based OASs are used to culture mussels and oysters, which are filter-feeders and do not require fishmeal diets.

Demerits of OASs

• Require fishmeal for feeding carnivorous species, leading to poor conversion ratios (e.g., 5kg of fishmeal is required to breed 1kg of fish).
• High fish densities increase disease and parasite transmission.
• Risk of fish escape and interbreeding with wild populations.
• Accumulation of fecal waste reduces water quality.
• Disposal of sticks and racks can be a concern in some areas.

Closed Aquaculture Systems (CASs)

• CASs involve land-based breeding of aquatic organisms in ponds, raceways, and tanks.
• They maintain a controlled interface between the reared species and the natural environment.
• Implement sophisticated waste management procedures that filter generated wastewater and cycle it back into the aquaculture system.
• Recirculating aquaculture systems are a typical example of a CAS.
• Species reared in CASs include Atlantic salmon, Cobia, Catfish, Tilapia, and European bass.

Key Elements of a CAS

• Monitoring: Continuous monitoring of water quality and fish health.
• Fish Handling: Proper handling and management of fish populations.
• Feeding: Artificial diets typically consist of fishmeal and fertilizers.
• Filtration Unit: Removes particulate matter and acts as a biofilter.
• Temperature Control: Water heating systems are sometimes required depending on water temperature and fish species.
• Aeration Unit: Provides dissolved oxygen for the fish.
• Ozone/Ultraviolet Sterilization: Reduces bacterial and organic loads in the water.

Advantages of CASs

• Maintain water quality due to negligible interference with natural waterways.
• Employ sophisticated waste management procedures.
• Prevent fish escape to surrounding waters.
• Reduce transmission of fish diseases and parasites.
• Improve fish quality and growth rates.
• Enhance food conversion efficiency.
• Reduce dependency on therapeutic treatments.

This quiz explores different types of aquaculture, focusing on Open Aquaculture Systems (OASs). Learn about their operational techniques, the species cultured, and the advantages and disadvantages associated with them. Test your knowledge on aquaculture practices!