Sometimes the cost of development and technology cannot be foreseen. Submarine cables do help global connectivity, no doubt about it. But they also have side effects. Some of them are very peculiar. For example, undersea cables are now known to affect crabs. How? By practically hypnotizing them.
What is the reason for this? Underwater cables generate an electromagnetic field. And this attracts the crabs and forces them to stay in place. It was discovered by Scottish marine biologists.
They’re scientists at Heriot-Watt University. They fear that this may affect the migration of crabs and harm the populations. This is reported in more detail in an article in the Journal of Marine Science and Engineering.
Researchers observed crabs at St Ebbs marine station. It is located in the Scottish Borders. Submarine power cables have a weak electromagnetic field. It can have a strength of 500 microtesla. It’s small, about 5% of the strength of the magnet on the fridge door. But with this strength, the crabs will crawl up the cable and become immobile.
This prevents them from obtaining food and searching for a mate. In addition, the reduced activity affects metabolism. The body begins to accumulate sugar and produces less lactate. Yes, the same scheme that usually results in human diabetes.
In addition, laboratory experiments proved more. The electromagnetic field damages the blood cells of crabs. This can lead to decreased immunity and other adverse effects.
The data obtained is important to consider when installing offshore wind farms. There are other structures associated with the laying of a large number of power cables. Now that it is known that submarine cables affect crabs, action can be taken.
Changes in crab behavior can not only harm the animals themselves. They can also affect the state of the seafood market.