Sales manager for Aquaculture at Signify, Steinar Grønnerud points out that it is crucial to avoid dark spots in the tank and to reduce stress for the salmon.
– Based on the customer’s situation, the depth of the tank and the water quality, we will develop a lighting plan where the light is as even as possible. In larger tanks and at a depth of more than 4.5 metres, underwater lighting should be considered as an addition to surface lighting. A light amount of 1000 lux on the surface and a minimum of 10 lux at the bottom of the system ensures optimal distribution of the light.
– When the salmon gets light for longer periods, it will eat more and grow faster. The lighting can be dimmed all the way down to 0.3% if required without light flickering. Flickering, sudden disturbances and non-natural photoperiodic behavior can make the fish stressed, which increases the cortisol level of the fish and thus constitutes the welfare of the fish, concludes Grønnerud.
Facts about Signify
Signify has been working with lighting for fish farming for over 10 years, based on a lot of research in this area. There is ongoing research collaboration with the Marine Research Institute in Bergen, the University of Shanghai and the University of Sterling in Scotland, where PhD students work in aquaculture. Five percent of Signify’s revenue goes back to R&D.