A significant aspect of aquaculture is the location and methods of the farm. Some systems are intensive and require substantial external resources to maintain a high output of fish.  Other systems are considered extensive, with little to no input required, though they may yield less output.  

 

Some common types of aquaculture systems and their requirements:

 

High-Risk Methods

Net pens are found in marine water (near-shore or in deeper offshore ocean waters) or in freshwater inland waters (ponds or lakes).  Pens are often enclosed but made from mesh or netting to facilitate water flow between the pen and the surrounding water.  This method of farming is typical for larger finfish, such as salmon, sea bass, and trout.

Artificial ponds can be semi- or fully enclosed, typically located near natural bodies of water. This type of system may contain species such as tilapia or shrimp. High-risk ponds allow discharge to escape, contaminating local waters.

 

Low-Risk Methods

Closed Systems are contained from the natural environment, minimizing risk of pollution, disease transfer, and escapes that could harm native species and flora. Examples of closed systems include:

  • Raceways utilize diverted water from nearby natural bodies, but appropriately treat wastewater and prevent escapes and disease transfer from the system to the environment.

  • Recirculating Aquaculture Systems (RAS) are designed to treat wastewater and reuse it within the system. Since RAS are entirely contained, they eliminate the concern of escapes.

Suspended Systems typically feature bivalves and seaweeds. Since these organisms are filter feeders, there is no wastewater, making these systems low risk–even potentially restorative.