Nofima has developed an automatic sensor to measure levels of nitrogen compounds in recirculated water – the first of its kind specifically for the aquaculture sector.
This technology is becoming more important since closed-containment aquaculture is being tested and becoming established. Recirculating aquaculture systems are used for closed-containment aquaculture on land, and high-quality measurements of water quality are crucial in such systems to ensure the welfare of the fish.
This new sensor will be particularly valuable in recirculating aquaculture systems for the measurement of the nitrogen compound nitrate. All recirculating aquaculture systems have a biofilter, which does not function properly when there are high levels of nitrite and ammonia in the water.
“We must give the fish the water quality required such that they are comfortable and grow optimally – since consideration of their welfare is given highest priority. Our knowledge about salmon and its welfare and performance in recirculating aquaculture systems has enabled us to adapt the technology such that it is well-suited to the biology of the salmon,” said scientist Jelena Kolarevic.
The sensor can continuously monitor water quality in recirculating aquaculture systems, and is a component of measurement equipment that measures eight parameters simultaneously. Facility personnel receive continuous on-line measurements of nitrite, total nitrogen compounds, pH, salinity, oxygen level, carbon dioxide level, total gas saturation and temperature. These levels can be read on a screen.
Using this technology should reduce costs and the need for expertise of facility personnel says Nofima, and should give reliable measurements of potentially toxic nitrogen compounds in aquaculture.
Nofima’s part of the work is a part of the EU project ‘AQUAlity’ and its role was to contribute expertise of fish needs and limits for various parameters of water quality, to test the prototype, and to evaluate how it can be further developed such that it can be used in recirculating aquaculture systems. The work was carried out in the laboratory and at the “Nofima Centre for Recirculation in Aquaculture” at Sunndalsøra, Norway.
Consortium partner OxyGuard is now planning to take the prototype towards commercialisation and sale to the industry.
