Technologies

Archival Tags [more info]

Wildlife Computers archival tags are designed to collect and record data on the swimming behavior of marine animals. Between the various models, you can sample depth, environmental temperature, stomach temperature, and light level. Light level can be used for determining geographic location on a coarse scale. Time is implicitly encoded with the stored data.

• Flexible user-programmable data sampling regimes.
• Data can be sampled and stored from once a second to once every 255 minutes.
• Mk9 archival tags can be programmed to collect light levels to be used for location calculation. PC-based software that estimates dawn and dusk times and calculates location based upon those times is provided with the tag order.
• Tags store 64 million readings as standard.
• Memory is non-volatile so collected data will not be lost even if the battery goes flat.
• Collected data are easily downloaded to a PC by the user.

Argos Tags [more info]

Transmitting tags are used when studying how an animal moves through its environment. Data are available without recapturing your animal. Data on the animal's behavior and environment are collected by the tag, summarized, and transmitted to you via the Argos satellite system. Argos also provides the geographical position of the tag based on these transmissions.

The Argos system consists of data acquisition and relay equipment attached to the NOAA low-orbiting weather satellites and ground-based receivers and data processing systems. The Argos satellite equipment records the transmissions from our transmitting tags and later downloads these data back to earth. Service Argos, the organization which administers the Argos system, then processes these data and determines your tag's position. Your data and the Argos-calculated locations of the tag are sent to you via the internet or on monthly CDs. Wildlife Computers supplies analysis programs to help you decode, format and interpret the Argos-relayed data.

Transmitting tags have an antenna that must be wholly above the surface of the water for transmissions to occur. Each transmission takes approximately 0.5 to 1.0 second. An Argos satellite must receive at least three transmissions during a pass over the tag in order to calculate the tag's location. The Argos system is currently one-way. That is, the tag does not know if a transmission was received by the satellite or not. Therefore, many transmissions must be sent to increase the chance that at least three are received by an orbiting satellite during a pass. Satellite pass durations vary between 5 and 20 minutes, and Argos dictates that a tag may not transmit any faster than once every 45 seconds. Marine mammals and sea turtles are good study animals because they spend enough time at the surface breathing to allow sufficient transmissions to be made.

For a more detailed explanation of the Argos System and how it works, visit their website.

Satellite tags have been deployed on many marine animals, including seals and sea lions, sea turtles, cetaceans, penguins, polar bears and fishes. We have developed a variety of configurations to suit attachment to different study animals.

For fish and other animals that do not remain at the surface for long periods of time, we have developed a specialized transmitting tag called the Pop-up Archival Transmitting (PAT) tag. The PAT collects and stores data throughout its deployment. It releases itself from the animal and floats to the surface on a user-specified date. Data are then transmitted to the Argos system.

GPS Tags [more info]

Wildlife Computers has incorporated Fastloc™ technology into an Argos-linked data recording tag in order to create a Fast-GPS tag. This tag addresses the difficulties inherent in deploying traditional GPS receivers on free-ranging marine animals which spend very little time at the surface. The ability to achieve highly accurate GPS locations, while requiring the tag antenna to be above the surface for less than one second, represents a major step forward in the ability to track marine animals.

The Fast-GPS tag (Mk10-AF) acquires the GPS signal snapshots, which can be completed in .008 seconds, and archives them along with depth and temperature data. On subsequent surfacing, a percentage of the summarized data and Fast-GPS snapshots are transmitted via the Argos system. Should the Mk10-AF tag be recovered, it yields the full archive of all Fast-GPS snapshots and sampled data.

Since the initial Mk10-AF, we have added the Fast-GPS capability to both standard archival (Mk10-F) and basic location-only Argos-linked tags (Mk10-AFB).

For more information on Fastloc™ technology, see Wildtrack Telemetry Systems.

Pop-Up Tags [more info]

Pop-up Archival Transmitting (PAT) tags are designed to track the large-scale movements and behavior of fish and other animals which do not spend enough time at the surface to allow the use of real-time satellite tags. As with traditional satellite tags, the PAT utilizes the Argos system for relaying summaries of the data collected. However, the data are transmitted at the end of the deployment when the tag detaches from the subject animal on a user-specified date.

Since PAT tags can yield data without the animal being recaptured, they offer a fisheries-independent means of tracking a target species. In addition, a full archival record is maintained in non-volatile memory. Thus, should the PAT be recovered, you will be able to retrieve the same detailed data as are collected by a conventional archival tag. A surprising number of PAT tags have been recovered by beachcombers and fisheries personnel.

The PAT tag is attached to the animal via a tether. Generally, the researcher determines the best tether design and attachment method.

While PAT tags have been used for a variety of applications, they were designed and are best-suited for medium to large fish. These tags are designed to transmit from an unobstructed ocean surface. Locations where overhanging reefs, kelp beds or marine debris occur may result in reduced transmitter performance. The anticipated deployment environment should be considered when evaluating the appropriateness of this technology. PAT tags have been successfully deployed on a variety of species, including tuna, marlin, and sharks, as well as swordfish and sea turtles.