France, May 15 -- The colour of the world's oceans is changing - a visible sign of climate disruption that scientists say could have wide-ranging consequences for marine life. The shift comes as world leaders prepare to meet in Nice next month for a major United Nations summit on ocean conservation.

In the Arctic and Antarctic, the water is becoming visibly bluer. Melting ice is allowing more sunlight to reach below its surface, changing the types of microscopic life that flourish there.

These tiny organisms - particularly plankton - help define the ocean's colour and play a key role in absorbing carbon dioxide.

"What gives the ocean its colour are primarily plankton communities," explained Vincent Doumeizel, who advises the UN on ocea...