Oceans

The world’s seas and oceans support nearly half of all species on Earth but we aren’t one of them. We can’t drink the salt water, walk on the surface, or breathe in it. Yet against all odds we’ve managed to carve a niche for ourselves in this most alien of environments. Now, over one-third of the total human population, nearly 2.4 billion people, lives within 100 km (60 miles) of an oceanic coast.

Few peoples have a deeper connection with the sea than the Bajau Laut of South-East Asia. Sometimes known as “sea gypsies”, they live in house boats or stilt houses built on top of coral reefs and when they do spend the occasional night on solid ground they often report feeling ‘landsick’.

Malaysia’s best Bajau free-divers can dive to depths of over 20 metres and stay there for several minutes on a single breath as they go in search of fish. And as if that weren’t enough, studies on some “sea gypsy” children from Thailand and Burma show that they have unusually good underwater-vision because their eyes have adapted to the liquid environment.

The Bajau Laut’s livelihood is traditionally totally dependent on the resources of the sea so spear-fishing is vitally important to them, but different cultures have very different ways of catching fish.

In the waters off Laguna in Brazil, fishermen have forged an extraordinary partnership with one of the smartest animals on the planet. Here the local fishermen use dolphins to drive shoals of mullet into their nets. When the fish are within catching distance, the dolphins leap out of the water as sign to the fishermen that they should now throw their nets. The dolphins then pick off the mullet as they break rank to escape from the nets.

But the ocean isn’t just about food. In ancient Hawaii, chiefs used surfing competitions to show off their power and prowess. Nowadays big-wave surfers do the same, monitoring conditions around the world to ensure they are in the right place at the right time when the giants come rolling in.

If only all our relationships with the sea were so benign. Sadly, it is now estimated that we may have removed as much as 90% of the oceans’ large fish. And since the oceans absorb 50% of the carbon dioxide that we release into the atmosphere by burning fossil fuels, we are continually increasing the acidification of the oceans.