Whale Shark and Megalodon: Monsters of the World Seas

With a length of up to 18 meters, the whale shark is the largest fish that populates the oceans today.

Similar to the blue whale, this imposing but completely harmless shark lives on plankton, which it filters out of the water.

He uses sophisticated cross-flow filtration to ensure that the filigree filter apparatus of his gills does not clog too quickly.

Although the whale shark, scientifically called

, is native to warm sea areas around the world, the International Union for Conservation of Nature (IUCN) lists it as endangered.

Populations are shrinking in the Atlantic, Indian and Pacific Oceans.

An international team of researchers recently discovered that deadly collisions with ships contribute significantly to this.

If whale sharks get in the way of small boats, a collision is rarely fatal.

However, the affected animal remains marked by scars for the rest of its life.

After colliding with a container ship, however, the fatally injured whale shark disappears without a trace because it sinks quickly.

In order to find out where there is a particularly great danger, the scientists working with Freya Womersley from the University of Southampton and Nicolas Humphries from the Marine Biological Association of the United Kingdom in Plymouth analyzed the ship movements in the range of the whale shark.

They used data from the automatic identification systems that are mandatory for larger merchant ships.

Recordings of the "Global Shark Movement Project" revealed where the fish roam: equipped with appropriate transmitters,

The hitherto underestimated source of danger for whale sharks

As Womersley and her colleagues report in the Proceedings of the US National Academy of Sciences, the sharks under observation spent almost half the time at such shallow depths that they came dangerously close to large ships.

Since cargo ships and tankers usually travel ten times as fast as the giant fish, whale sharks hardly have a chance to avoid them.

Areas where whale sharks thrive include the Gulf of Mexico, the Persian Gulf, the Red Sea, the Gulf of California and around the Philippines.

These hotspots often overlap with busy sea areas.

Whale sharks also often cross heavily frequented shipping routes on extensive migrations.

For seven satellite transmitters, the latest signals received indicated that their carriers sank into the deep sea after a fatal collision.

The other transmitters often stopped working when the whale shark in question had reached a busy shipping route.