Mysterious sea circles that appear on the seabed near Denmark are created by eelgrass, and are a result of agricultural runoff. Hope you’re not too disappointed that it’s not fairies or aliens.
Eelgrass grows in clumps, with older plants in the middle and younger ones near the edge. The build-up of toxic sulphides from a combination of bacteria and agricultural runoff kills off the older and younger plants, leaving perfect circles of mid-aged grass.
Researchers have invented a robot jellyfish, fueled by hydrogen, that could one day be used for ocean rescues. The vehicle, called Robojelly, uses shape memory alloys – metals that ‘remember’ their shape.
A type of plankton, called copepods, leap out of the surface of the ocean to avoid being eaten by fish. These tiny and brightly-coloured shrimp-like animals live just under the surface of the sea and can ‘fly’ 10 to 20 times the length of their body.
Corals can inflate themselves to avoid being buried in the sand.