There is so much to learn about our oceans… even in our own environmental gem on doorstep in Strangford Lough.
New scientific evidence shows that primitive marine animals, called chitons, have an internal compass that can sense magnetic fields.
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Scientists have made an interesting discovery about primitive life forms in our seas.[/caption]Work by an international team in Queen’s University Belfast who have a marine research base in Portaferry and two universities in the USA have uncovered proof that these creatures sense and respond to the pull of earth’s magnetic field. Magnetoception, the sensitivity of organisms to magnetic fields, or an internal ‘compass’, has been found in sharks, birds, turtles, and even bacteria, and has been proposed to explain many complex behaviours including coordinating the impressive migrations of birds and sea turtles.
There is popular speculation over the existence of subconscious geomagnetic sensitivity in humans with particularly good directional sense. But the source of a magnetic sense organ remains elusive.
Chitons are often called “living fossils” thanks to their resemblance to their ancestors from 300 million years ago. They use an astonishing set of teeth reinforced with iron to scrape material off rocks on the seashore. All chitons grow this tooth ribbon or radula coated in magnetite that the animals produce themselves. This led scientists to suspect they might be able to sense magnetic fields. Chickens also grow small amounts of iron in their beaks, and have a strong internal compass, but if their beaks are trimmed they can lose their sense of direction.
New experiments on chitons used an electromagnet to literally change the direction of north inside a laboratory in the USA. When the animals were left alone in normal conditions, they all travelled north-north-west. But when the magnetic field was artificially changed, the animals became confused. “This shows they can sense the magnetic field direction, but it’s quite low down on a hierarchy of navigational pointers,” explains Lauren Sumner-Rooney, a PhD student in Queen’s University Belfast and the lead author on the published study. “This new discovery of magnetoception in a very simple organism will provide a good manageable system for scientists to work with and learn more about this amazing ability.”
Humble sea creatures may hold the secret of how some people just “know” which way north is!
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