Brinicle

BrinicleBrinicles are long ice fingers that slowly form under the sea until it reaches the seafloor and freezes the ground including the creatures along its way. This happens when the salt-heavy brine accumulated within the frozen sea ice leaks out and flows down freezing the surrounding water, forming a descending tube of ice.

When the seawater freezes as it comes into contact with the brinicle it is a lot more spongelike than normal ice.

They are usually found in the Antarctic when saline water is introduced to the ocean.