Tag Steven Summerfelt

El reciente Taller de Innovación Acuícola de 2017 en Vancouver reunió a numerosas partes interesadas involucradas e interesadas en el cultivo de peces, en particular los salmónidos, en la creciente industria de los sistemas de contención cerrada. 

In the second of a two-part series, Steven Summerfelt discusses various efforts to improve knowledge of closed-containment systems, innovations in fish feed and presents comprehensive concluding remarks. 

The recent 2017 Aquaculture Innovation Workshop in Vancouver brought together numerous stakeholders involved in and interested in fish farming – particularly salmonids – in the growing industry of closed-containment systems. 

German researcher believes that floating fish feces – stemming from cork used in feed blends – would help recirculating aquaculture systems more efficiently remove suspended solids. The big question is, will feed manufacturers get on board? 

Woodchip bioreactors can efficiently remove nitrate, phosphorus and total suspended solids from aquaculture wastewaters. Denitrification treatment of the relatively organic-rich aquaculture wastewater is a new and useful application to protect against water pollution. 

A number of large salmon farming companies are now investing significantly to increase land-based, water recirculating aquaculture systems (RAS) in northern Europe and North America, and there is likely a need for more trained farm personnel to run and manage these and other close-containment aquaculture facilities. 

A recent study evaluated the effects of a fishmeal-free diet on Atlantic salmon performance and fillet quality during successful growout to market-size in a commercial-scale, land-based, closed-containment system using water recirculation technology. Test fish performed well, with 97 percent survival during the 10-month growout period. 

To evaluate the application of an air pressure-based transport method within a recirculating aquaculture system, the authors performed testing with harvest-size salmon at The Conservation Fund Freshwater Institute. 

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. 

Research at the Conservation Fund’s Fresh­water Institute is evaluating a prototype percussive stunning system for slaughtering food-size rainbow trout. 

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

Pure oxygen transfer columns and vacuum degassing columns can be used to drive dissolved nitrogen gas concentrations down to sub-saturation levels.