Video: Dolphins Play with "Bubble Rings"
Dolphins Play with "Bubble Rings"
Dolphin intelligence and complex play
Dolphins are known to engage in complex play behaviour, which includes such things as producing stable underwater air-core vortex rings or "bubble rings."
There are two main methods of bubble ring production: rapid puffing of a burst of air into the water and allowing it to rise to the surface, forming a ring; or swimming repeatedly in a circle and then stopping to inject air into the helical vortex currents thus formed.
The dolphin will often then examine its creation visually and with sonar. They also appear to enjoy biting the vortex-rings they've created, so that they burst into many separate normal bubbles and then rise quickly to the surface.
Certain whales are also known to produce bubble rings, or even bubble-nets for the purpose of foraging. Many dolphin species are also known for playing by riding in waves, whether natural waves near the shoreline in a method akin to human "body-surfing", or within the waves induced by the bow of a moving boat in a behavior known as bow-riding.