Tracking fish movements in the ocean

Until recent technical developments, such as the use of satellite telemetry, little has been known about the movements, physiology and behaviour of long-distance migratory fish. Recently, Bloch and co-workers used electronic data storage tags surgically implanted into bluefin tuna Thunnus thynnus or linked to satellites, to reveal interesting details of the movement patterns, area use and environmental preferences of these fish. These studies should be extended to other marine animals for which the breeding biology, genetic population exchange and migrations are still largely unknown.