The air we breathe: The ocean produces over half of the world's oxygen and absorbs 50 times more carbon dioxide than our atmosphere.

Climate regulation: Covering 70 percent of the Earth's surface, the ocean transports heat from the equator to the poles, regulating our climate and weather patterns.

1. The Ocean produces more oxygen than the Amazon.

It is often thought that rainforests are the primary source of oxygen on the planet, but the truth is that rainforests are only responsible for 28% of the oxygen on earth while oceans are responsible for the 70%. It does not matter how far we live from the sea, from every ten breaths you take seven come from the ocean.

Have you ever seen a tree in the middle of the sea? No, right? That is because the Ocean does not need them, the phytoplankton has got it covered. Phytoplankton is a microscopic plant, a component of the plankton, which spends its life being carried by oceanic currents. Basically, these tiny little organisms act in the same way as tree leaves do on land. Phytoplankton absorbs carbon dioxide and releases oxygen. We do not see them, so we tend to forget about them if we even know about them in the first place. They are one of the tiniest beings on the planet, but one of the most important to have around, keeping us alive.

2. The Ocean regulates the Earth climate.

In many ways, the sea regulates our climate. It soaks up the heat and transports warm water from the equator to the poles, and cold water from the poles to the tropics. Without these currents, the weather would be extreme in some regions, and fewer places would be habitable.

It regulates rain and droughts. Holding 97% of the water of our planet, almost all rain that drops on land comes from the sea. The ocean absorbs CO2, to keep the carbon cycle, and accordingly temperatures on earth, in balance. It is like our global climate control system.

3. Many creatures depend and live in the Ocean.

The ocean is not just home to us ocean lovers, but it is home to the greatest abundance of life on our planet. When you sail across an ocean, you will see dolphins, whales or a turtle popping up to take a breath. That is just what we see on the surface; there is more life below the ocean’s surface than on land. Experts predict4 that there are more than 300.000 different species underwater, and is still not clear how many of them we know.

All the creatures that live in the Ocean play an essential role in the trophic chain of the ecosystems. Due to climate change (5), the ocean has been warming and losing oxygen, and its pH has been decreasing. Many marine species have already been adjusting their geographic and depth ranges with changes in sea temperature. However, not all species may be able to move to avoid thermal stress, and global warming has already been correlated with mass mortalities in the Mediterranean.

With more than 60% of the world’s population living on the coastline, we all depend on a healthy sea just as much as these beautiful creatures.

“The sea, the great unifier, is man’s only hope. Now, as never before, the old phrase has a literal meaning: we are all in the same boat.”- Jacques Yves Cousteau

1. It helps us breathe

Phytoplankton – tiny plant-like organisms that live in the sea – are responsible for at least 50% of the oxygen on Earth. Just like land-based plants, they contain chlorophyll to capture sunlight and use photosynthesis to convert it into the energy they need, producing oxygen as a byproduct. They also consume carbon dioxide, transferring about 10 gigatonnes of carbon from the atmosphere deep into the ocean each year.

2. It helps regulate the climate

The ocean absorbs huge amounts of heat from the sun. “More than 90% of the warming that has happened on Earth over the past 50 years has occurred in the ocean,” according to the US National Oceanic and Atmospheric Administration.

That heat tends to be at its most intense nearer the equator, with the water nearest the surface warming the most. Sea currents then transport that heat around the world; north and south, towards the poles. As some of the sea water evaporates it becomes denser and heavier, due to its relatively higher salt content. That causes it to sink, taking some of the warm water deeper.

From the surface to the depths, sea temperatures are rising.

Image: NOAA

Some currents are directly responsible for specific climatic effects. One example is the Gulf Stream, which takes warmer water from the Gulf of Mexico across the Atlantic to Europe. If the Gulf Stream were disrupted, much of the western part of Europe – including the UK, Ireland and France – could become colder.

3. It’s an important source of food

Fish is on the menu for billions of people around the world every day. It accounts for almost 16% of all animal protein consumed globally. Of course, there’s more to seafood than fish, crustacea and other edible creatures. A range of algae and sea plants are also commonly used in cooking.

The UN Food and Agriculture Organization lists sodium, calcium, magnesium, and iodine among some of the important nutrients in seaweed. Iodine deficiency has been identified as the “most prevalent and easily preventable” cause of impaired cognitive development in children.

Pressure on resources and the environment have led to calls for food production and for people’s diets to change. A cow, for example, produces 2.8kg of greenhouse gas per kilo of live body weight and needs 10kg of feed for every kilo it weighs.

Plus, to get just one gram of protein from cattle, you need 112 litres of water. The oceans, if properly managed and maintained, could form an important part of a more sustainable approach to feeding the planet’s growing human population.

4. Its biodiversity is incredible

It’s not just a source of food. The ocean is also home to an abundance of life. While estimates on the number of species that live in the sea exist, no one knows with absolute certainty what that number is.
According to the US National Library of Medicine’s National Institutes of Health, “91% of species in the ocean still await description.” That’s due in no small part to the vastness of the oceans, which cover around 70% of the planet’s surface and are up to 11,000 metres deep. The number of yet-to-be-discovered creatures living in the sea could easily run into the millions.

Back from the dead: The return of a living fossil.

Image: BrokenSphere / Wikimedia Commons

One example of how mysterious the deep oceans can be is the coelacanth. Found in fossils and believed to be extinct, a living coelacanth was pulled out of the ocean in 1938 off the coast of South Africa.

This fascinating deep-water creature could yield invaluable insights into how marine animals were able to adapt to life on land, as the way they move their fins resembles the way many four-legged creatures walk.