ScaleAQ, a technology supplier for the aquaculture industry, acknowledges the need to improve the fish welfare, reduce mortality and improve the production through the development of technology for sustainable aquaculture . The fish health report (2023) gives every year the status on Norwegian aquaculture regarding fish health . The report shows the highest mortality rates ever recorded and highlights three health issues, i.e. injuries from mechanical delousing operations , complex gill diseases, and bacterial diseases ( winter ulcers). It further highlights jellyfish as one of the top ten health challenges. Increasing global sea temperatures and marine heat waves and low oxygen conditions could also have a negative impact on future aquaculture production.
ScaleAQ is currently developing and testing a submerged production concept (SubSea) in collaboration with a Norwegian fish producer . The function and goal of SubSea is to improve fish health by avoiding surface challenges such as lice, algae, jellyfish, high and low temperatures, as well as forces from waves and currents on moorings and floating collars. The concept is intended for use in exposed and existing (deep) locations. The depth and water quality of the location must be suitable for deep-sea operations.
ScaleAQ’s comprehensive design for submerged operations has been extensively tested in tank simulations. The Subsea system consists of a floating collar with a circumference of 120-200 meters and a cylindrical net pen with a net roof. The net is lowered to a depth of 25 m, significantly reducing the risk of infestation with sea lice and avoiding other surface challenges. In submerged operations, fish are prevented from going to the surface, filling their swim bladder with atmospheric air, as well as engaging in jumping and other surface-related activities. To compensate for this, an air-filled dome is installed in the net roof, providing fish with the opportunity to fill their swim bladder. Lights are mounted underneath the net roof, as well as around the air dome, to illuminate the area. C ameras are installed to observe fish behaviour and feeding activity, and oxygen sensors are employed to monitor oxygen levels. Winches are mounted on the floating collar to ensure safe and efficient lowering and raising of the net pen.
Submerged systems and related technology on a commercial scale has been tested over the years through development licenses and continued in regular production at multiple sites. Published summaries of full-scale operations are available (Warren-Myers et al, 2021), indicating reduced lice infestation, normal swimming behaviour, and impact on animal welfare due to suboptimal environmental conditions. Scientific efforts to document the effect of submerged concepts on health, welfare, and production biological parameters have been ongoing intensively for a decade, although trials of submerged concepts date back to the 1970s (Sievers et al, 2021).
At the conference we will present the work that ScaleAQ is doing on subsea farming, and present the status regarding sealice infestation, growth and welfare, as well as technical results.