Dolphins attracted by magnets?

This video is about bottlenose dolphins and their sounds.

From Wildlife Extra:

New study finds dolphins may be attracted to magnets

The behaviour of six bottlenose dolphins were analysed in the study.

A study undertaken by researchers from the Ethos unit at the Universite de Rennes in France has revealed that dolphins could be magnetoreceptive, which means they have the ability to perceive a magnetic field.

In the wild, the ability of marine mammals to follow migration routes suggests that they might be sensitive to geomagnetic fields, but until now there has been no experimental evidence to confirm this.

Research was conducted at the delphinarium of Planete Sauvage in Port-Saint-Pere, France, and looked at the behaviour of six bottlenose dolphins in response to two separate barrels. One barrel contained a strongly magnetised block, and one contained a demagnetised one. Apart from this detail, the blocks were identical and indistinguishable to the dolphins when they used echolocation.

The dolphins were seen to approach the barrel containing the strongly magnetised block much faster than they approached the barrel with the unmagnetised block. In order to ensure a fair experiment, the dolphins were free to swim in and out of the pool were the barrel was placed, and the person placing the barrel in the pool, and analysing the videos of the dolphins’ reactions, did not know which barrel was magnetised.

Dorothee Kremer, a researcher in the experiment, explains the importance of the study’s findings: “Dolphins are able to discriminate between objects based on their magnetic properties, which is a prerequisite for magnetoreception-based navigation. Our results provide new, experimentally obtained evidence that ceteaceans have a magnetic sense, and should therefore be added to the list of magnetosensitive species.”