A data logger tag for the study of slaughter procedures in aquacultured salmon

Abstract

This paper describes a micro controller based data logger designed to be externally attached to fish, in this case adult Atlantic salmon. The logger can measure ambient temperature and the temperature difference between ambient and dorsal white muscle, the latter with high resolution and accuracy. Communication with a computer for data transfer pass over a detachable transformer coupling. This transformer is also used to charge the internal battery. The logger can thus function without connectors, eliminating corrosion problems and simplifying encapsulation. Tracking of the muscle temperature is important for the development of better slaughter procedures. But the principles described in the following can also be useful for conventional tags and other kinds of underwater equipment.