A great white shark in the mood for jokes! Yes, because a great white shark has drawn what looks like a giant self-portrait, or a drawing of a whale, moving in the Atlantic Ocean with its GPS. The GPS marker works quite simply.
When the animal emerges on surfaces, the antenna locks onto the satellites and the position is plotted on a map in near real time. Along the North American coast, the white shark has generated so many signals that once united they look like a stylized drawing of a shark or a whale!
This particular shark is a male called Breton, about 4 meters long and weighing 652 kilograms. Breton moves from the coast of New Jersey, via Long Bay in South Carolina, to Virginia. The white shark is currently threatened and is among the species protected by the Convention on International Trade in Endangered Species (CITES).
Specific laws have also been approved by the states of: Australia, South Africa, Namibia, Israel, Malta, Italy, California, Florida and New Zealand. Australia has developed a comprehensive recovery plan for the great white sharks in its waters.
The causes of the decrease in specimens consist in the depletion of the fish stock on which the white shark feeds, accidental fishing especially in traps or spadare, that for sporting purposes or aimed at the marketing of teeth, fins or complete jaws and the presence of nets at the derives.
As for the other sharks, it is the object of commercial fishing for food purposes for the preparation of shark fin soup even if it is not among the privileged species and its meat does not seem to be particularly valuable.
IUCN put it on its red list by classifying it as vulnerable, an estimate made when it was believed that the white shark was a fundamentally sedentary animal. Recently, however, a study by the University of Stanford has shown that the white shark migrates up to 18,000 km, so lately it is assumed that the same specimen has often been counted several times.
This means that the white shark population in the world has so far been greatly overestimated and a future update of the risk status is hypothesized, as the new calculation proposed by Stanford University assumes the presence of only 3,500 specimens worldwide, less than tigers.