Prototype archival tags for studying the migratory routes of tuna

Archival electronic tags can be used for studying the migratory patterns of tuna, identifying their feeding and spawning grounds, etc. The size of the tag has to be miniaturized, to the extent possible so that by way of attaching such devices the swimming and natural behaviour of the tagged species remain unaffected. The design and development prototype archival tags for sampling the physical parameters of the ocean such as pressure, temperature and light intensity at preset intervals of time is presented in this paper. The tag has been encapsulated and its performance validated in the laboratory as well as in an open test facility in a reservoir.