Investigation of growth performance of post-smolt Atlantic salmon (Salmo salar L.) in semi closed containment system: A big-scale benchmark study

• Published in: Aquaculture Research
• Main Authors: Øvrebø, Tarald Kleppa, Vigo, Pablo Balseiro, Imsland, Albert, Stefansson, Sigurd Olav, Tveterås, Ragnar, Sveier, Harald, Handeland, Sigurd Olav
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2022
• Subjects: VDP::Landbruks- og Fiskerifag: 900; Norway; Atlantic salmon; Salmo salar
• Online Access: https://hdl.handle.net/11250/3059713; https://doi.org/10.1111/are.15919

The Norwegian salmon industry faces challenges related to sea lice (Lepeophtheirus salmonis) infestations, escapees, diseases and environmental impact. Semi-closed containment systems (S-CCS) have been proposed to abate these challenges. In the S-CCS, cultured fish are separated from the natural environment by a physical barrier, reducing the time fish spend in open sea cages. Production data from six cohorts of salmon were used to compare growth and performance of fish raised in S-CCS and in open sea cages (control group) incorporating different seasons. The study was carried out in two phases. Phase one used post-smolts from approximately 100 to 800 g in seawater, and fish in S-CCS were compared with a reference group from an open sea cage. The second, grow-out phase covered the size range from approximately 800 to 5000 g in open sea cages; here fish previously reared in S-CCS were compared with fish from a control group. The study showed a significantly lower infestation of sea lice in S-CCS (0.02–0.04) fish compared with the control group (0.18–0.62) during the post-smolt phase. Furthermore, in the grow-out phase the S-CCS group showed higher growth rate and higher final weight (4680 g [spring], 4890 g [fall]) for the S-CCS group compared with the control group (3800 g [spring] and 4080 g [fall]). Salmon raised in S-CCS showed significantly higher survival compared with the control group in open pens, indicating increased resilience in fish raised in S-CCS when transferred to open net pens in sea. It is concluded that S-CCS have advantages compared with exposure to the natural environment in open pens in western Norway. publishedVersion