Tag John Davidson

The use of larger and deeper tanks can reduce building, labor and other aquaculture production costs. However, the ability to grade and transfer large numbers of fish is more challenging when using large tanks. In a comparison of the effectiveness of a purse seine and a hinged clamshell to crowd fish in large tanks, the latter was easier to control and less stressful to salmonids. With a slotted bar rack in a side panel of the clamshell crowder, fish were simultaneously graded in size. 

Dozens of land-based, closed-containment salmonid RAS systems are coming on line. New projects are bringing new principles into the salmon industry. Industry expansion hinges upon the development of pollution-mitigating technologies to reduce nutrients in effluents. 

The benefits realized by recirculating aquaculture systems – including enhanced fish growth, product quality and survival, as well as reduced treatment costs – have made the RAS approach an important production trend. 

A study to evaluated operating practices and system designs that could potentially enhance depuration of off-flavors from Atlantic salmon cultured in a semi-commercial-scale freshwater recirculating aquaculture system. 

Circular tank-based recirculating aquaculture systems can be used to effectively culture rainbow trout and other salmonids in a bio-secure and environmentally friendly manner that imposes a much lower water and wastewater footprint than traditional flow-through culture technologies. 

In a study, a radial-flow settler provided approximately twice the TSS removal efficiency of a comparable swirl separator. 

As confirmed in a U.S. study, partial-reuse systems are effective alternatives to traditional, serial-reuse raceway systems for salmonid culture.