A system for online assessment of fish welfare in aquaculture

Aquaculture sea cages can now be more than 30 meters deep. It has therefore become next to impossible for fish farmers to form a complete picture of the welfare situation of the fish. It is consequently all ]important to develop an automatic system for continuous assessment of fish welfare in sea cages. One such system under development is the Welfaremeter. The Welfaremeter consists of a profiling probe (CTD), a control unit, a database, an expert software program and an internet webpage. The probe measures temperature, oxygen, salinity, fluorescence and turbidity for each half meter downwards in the cage. The control unit determines how often the probe profiles the water column and sends the measurement data via the mobile phone network (GPRS) to a database at The Norwegian Marine Data Centre, Institute of Marine Research. These data are then analysed by the expert software which gives an evaluation of the environmental conditions in the cage as either very good, fair or potentially harmful for the fish. Future versions of the expert software will also give possible reasons for poor environmental conditions and advice for how the farmers, if possible, can remedy the situation or at least diminish harm to the fish. The high density of fish farms in many costal zones means that the Welfaremeter has potential as a future source of data for environmental and fisheries research. The purpose of this talk is to give an insight into the present prototype and how we plan to improve the system further. Keywords: Fish welfare, CTD, GPRS, expert softwar