How it works:
Smaller creatures like fish and birds can be equipped with devices that record and store tracking information for retrieval at a later date. Known as archival or data storage tags, these instruments are placed in or on an animal and act like tiny computers, constantly sensing and recording the environmental conditions that they travel through. These tags can take new readings as frequently as every 4 seconds if desired. Despite their small size, Lotek archival tags have batteries and memories with enough capacity to collect data for several years. They are constructed to ensure reliable operation at depths of up to 2000 meters and temperatures as low as -5° C.
Archival tags measure water temperature, water pressure and light levels. From these measurements researchers can reconstruct a comprehensive daily history of a an animal’s travels. The water pressure reading reveals the animal’s precise water depth, while using an elegant process known as light-based geolocation, the light measurements contain enough information to allow calculation of the animal’s latitude and longitude. The unsurpassed light sensitivity of Lotek archival tags ensures that users can gather the most accurate geolocation estimates possible.
As with some types of GPS work, archival tag research relies on equipment retrieval for its success. Some tags are labelled with an offer of reward to those who capture the animal – it’s not unusual for these returns to come from surprisingly distant locations. Lotek has also introduced a second retrieval option: archival tags with “pop off” mechanisms. These tags can be programmed to detach from their subjects at specific times just like remote-release GPS collars. These tags float to the surface of the water and emit signals to facilitate recovery once they are detached.
When it’s used:
Archival tags offer an excellent alternative for monitoring aquatic, avian and terrestrial species when radio or acoustic telemetry is not possible or practical. Lotek tags have been used on such diverse species as tuna, salmon, cod, plaice, sharks, sablefish, lake trout, turtles, penguins, albatross and platypus.
Lotek Archival Products