Ocean Facts
More than just water
The big blue
• The ocean covers nearly three quarters
of the planet’s surface.
• It contains 97% of its water and has an
average depth of nearly 4 kilometres.
Invisible life
• Every teaspoon of seawater contains
thousands to millions of mostly unnamed
microscopic organisms.
• The total weight of marine microbes is greater
than that of fish and whales combined.
Global air conditioner
• The ocean provides half the world’s
oxygen and absorbs a quarter of the
carbon dioxide we produce.
• Ocean circulation cools the tropics
and warms the poles.
We are changing the ocean
Sea level seesaw
• Around 125,000 years ago, sea level was
4 metres higher than today. 20,000 years
ago it was 120 metres lower.
• Today, the rate of sea level rise is accelerating.
Goodbye Arctic ice
• Arctic sea ice has decreased by a third
since the 1970s.
• It is likely to disappear completely in
summer by 2040 – maybe even sooner.
Fish stocks under pressure
• Around 130 million tones of fish are taken
from the seas every year.
• Most commercial fish stocks are over exploited.