The equipment, called SmartTag, is attached to the fish and measures how often and how much the pressure changes in the mouth, and with that, the breath of the fish. From the tag, audio signals are sent to an under-water microphone, forwarding it to a computer where a programme calculates the breathing activity. Previous and ongoing laboratory studies have demonstrated that breathing activity is a good welfare indicator in fish, responding both to variation in water quality and to other types of stress factors.
Transmitters attached to the fish have been used for many years, e.g. to map where the fish swims. But measuring the well-being of the fish is a new use. We envisage that in the future, fish farmers can monitor their fish by having a certain number with this equipment in the net cages. Abnormal breathing activity indicates something is wrong, and measures can be implemented. So far, successful testing of the equipment for use on cod has been carried out at Fiskeriforskning this autumn. The technology will initially be used in SEAFOODplus research work on cod and sea bass in Norway and France, respectively.
The SmartTag prototypes were developed for SEAFOODplus by the technology company Thelma (
www.thelma.no) in Trondheim, Norway.
