Shark Shop

Different tagging methods:

• Passive tags with a unique optical (e.g. Spagetti tags) or electronic (RFID chip) code that are attached to a shark. If the shark is caught again, information is obtained that a) the shark has been caught before and b) the distance it has traveled since the tag was attached. These tags are relatively inexpensive and are also suitable for smaller sharks. After tagging, no further information about the shark is obtained unless it is caught again. However, the probability of recapture is low.
• With acoustic tagging, transmitters are attached to the shark or implanted under the shark's skin. The required receivers are fixed underwater at locations of particular interest for the research question. If a shark with a transmitter swims past the receiver, this event is recorded by the receiver. Depending on the number and positions of the receivers, the whereabouts and duration as well as the distances traveled between the individual receivers can be determined for the tagged sharks. But only then. At 350-750 US dollars per transmitter and approx. 2,000 US dollars per receiver, the transmitters are considerably more expensive than passive tags but much cheaper than satellite transmitters.
• There are two basic types of satellite transmitters, which complement each other functionally:
  • PSAT (Pop-up Satellite Archival Tags) transmitters are attached to the shark and record various data such as depth, light conditions, temperature and similar. After a predetermined period of time (e.g. 6, 12 or 24 months), they detach from the shark, float to the surface and send all their data to the scientists via a satellite. The cost per transmitter is between 2,000 and 5,000 US dollars, depending on the functions and service life.
  • SPOT (Smart Position and Temperature Tag) transmitters are attached to the shark's dorsal fin and have a fixed antenna. As soon as the shark swims on the surface of the water, the transmitter sends its position and temperature to the scientists via a satellite. The cost per transmitter is between 1,750 and 5,000 US dollars, depending on the functions and service life.
  Due to the size of the transmitters, satellite transmitters are only suitable for larger shark species.

SPOT transmitters are best suited for individualized shark adoptions, as they can be used to display the known detailed routes that a shark travels with the transmitter. All other methods say very little about the actual movements of a tagged shark and whether it is still alive at all.

Costs:

In addition to the pure material costs, a shark tagging expedition usually involves costs for flights, transportation, ships, crew, fuel, lines, bait, specialists to analyse the satellite data and other costs. The installation of a single transmitter can quickly cost over 5,000 US dollars. The Shark Foundation itself only supports research projects with satellite transmitters in rare exceptions. With the cost of just one transmitter we can support other shark research projects, e.g. in Angola, Greece, Spain or India, for a year.

Risks:

In addition, satellite transmitters do not always transmit data over their planned lifetime. The sea is a harsh place. A shark can be eaten or caught, die or tear off its transmitter. From time to time, the very complex transmitters simply stop working due to damage or other defects.

Shark Adoptions

Tagging with passive methods is cheap, but says very little about the adopted shark. It is tagged and only rarely is a recapture reported. Such sponsorships are offered online, but do not seem very attractive to us.

Adoptions with acoustic and satellite tags are either very expensive or a large number of sponsors share one shark. Such adoptions are also associated with a certain risk of the transmitters not working or the shark dying for whatever reason. Sponsors who have spent a lot of money on a shark adoption would certainly be anything but pleased if the shark simply disappeared from the screen after a few weeks or months. This is why the Shark Foundation does not offer individual shark adoptions.