Known as black holes of the ocean, ocean eddies trap water like black holes suck up light in space.

A whirlpool is a body of swirling water formed when two opposing currents meet or a current running into an obstacle, and an eddy is a massive whirlpool that is spinning against the main current, which usually swirls billions of tons of water. 

Massive eddies are surrounded by tight barriers where the fluid moves in closed loops. They act as a container for the water trapped inside them. Water temperatures and salt content within the eddies can be different from the surrounding ocean. 

As they drift across the sea, they act as transporters for micro-organisms like plankton, or even for human trash such as plastic waste or oil. By serving as temperature and salt taxis, eddies could counteract some of the negative effects of global warming. 

According to NewScientist, studies suggest that eddies could be helping to slow climate change because scientists found that Agulhas rings, the western boundary current of the South Indian Ocean, could carry warm water northwards away from southern sea ice, which could help slow the melting of the ice, and add cold and less salty water to the oceans, affecting global currents and in turn weather.

About The Blue World series:

The ocean covers more than 70 percent of the Earth. In this blue world, there are all kinds of marine life with surprising abilities we don't know about. In this series, CGTN guides you through the journey of exploring the amazing animals in the ocean. 

For more:

The Blue World: The mystery of the sex of green turtles

The Blue World: Brainless jellyfish

The Blue World: Half asleep, half awake dolphins

The Blue World: Never make a pufferfish angry

The Blue World: From round fish to flatfish

The Blue World: When a whale sinks into the sea

The Blue World: Sea otter's treasure chest

The Blue World: Mother octopuses' mission

The Blue World: When the beauty of coral fades

The Blue World: Whale beachings

The Blue World: A shark's sixth sense

The Blue World: The glowing sea

The Blue World: Far away from the shore

The Blue World: When two oceans meet

The Blue World: When a huge wave comes in

(If you want to contribute and have specific expertise, please contact us at nature@cgtn.com.)