Five reasons why the oceans are so important

We must protect our oceans.

By Sean Fleming, Senior author and content creator

Unless you block all information, you must know that the oceans are vital to life on Earth. But why?

Here are five reasons why we need to protect the future of our oceans.

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1. The ocean helps us breathe

Phytoplankton are tiny organisms that live in the ocean. Like plants, they produce at least 50 percent of the oxygen on Earth.

Like land plants, they contain chlorophyll to capture sunlight and convert it into energy using photosynthesis, as well as producing oxygen and consuming carbon dioxide. Each year, phytoplankton transfer about a billion tons of carbon from the atmosphere to the oceans.

2. Oceans contribute to climate regulation

The oceans absorb much of the heat from the sun. According to the National Oceanic and Atmospheric Administration, "more than 90 percent of the warming on Earth over the past 50 years has occurred in the oceans."

This solar heat tends to be strongest near the equator, with water closest to the surface warming the most. Ocean currents then carry heat around the world, reaching the poles in both the north and south directions. As surface water heats up and evaporates, its salt content increases, making it denser and causing it to sink, allowing some of the warmer water to reach deeper areas.

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

Some currents contribute directly to specific climate impacts. One example is the Gulf Current, which carries warm water from the Gulf of Mexico from the Atlantic Ocean to Europe. If the Gulf current breaks down, much of Western Europe, including the UK, Ireland and France, could become even colder.

3. The ocean is an important source of food

Fish feed billions of people around the world every day. It accounts for nearly 16% of global animal protein consumption. Seafood, of course, is not just fish, but also crustaceans and other edible Marine life. A range of algae and Marine plants are also commonly used in cooking.

The Food and Agriculture Organization of the United Nations lists some important nutrients in seaweed, such as sodium, calcium, magnesium and iodine. Iodine deficiency has been identified as the "most prevalent and preventable" cause of impaired cognitive development in children.

Pressure on resources and the environment has led to calls for changes in the structure of food production and the human diet. For example, a cow produces 2.8kg of greenhouse gases per kg of body weight and requires 10kg of feed per kg of body weight.

In addition, it takes 112 litres of water to get one gram of protein from a cow. If managed and maintained properly, oceans can be an important part of a more sustainable food source to feed the planet's growing population.

4. The biodiversity of the oceans is incredible

Not only is the ocean a source of food, it's also home to many kinds of life. While we can estimate the number of species living in the ocean, no one knows for sure what that number is.

According to the US National Library of Medicine's National Institutes of Health, "91 per cent of Marine species remain in a state to be described". This is due in large part to the vastness of the ocean, which covers about 70 percent of its surface area and is as deep as 11,000 meters. The number of undiscovered creatures living in the sea can easily reach the millions.

Coelacanth Back from the dead: The Return of Living fossils.

The coelacanth is an example of the mystery and unfathomability of the deep sea. Coelacanths have been found in fossils and were thought to be extinct. But in 1938 fishermen accidentally caught a live coelacanth off the coast of South Africa.

This fascinating deep-water creature could provide valuable insight into how Marine animals adapt to life on land, as their fins move in a manner similar to the way many tetrapods walk.

5. The oceans create millions of jobs

A report by the Organization for Economic Cooperation and Development estimates that the Marine industry will employ more than 40 million people worldwide by 2030, with the largest share likely to be in the fishing sector, followed by tourism.

Of course, the economic health of the shipping industry is also essentially tied to the overall health of the oceans. The Marine economy is particularly important in developing countries, where most of the 3bn people who depend on the sea for their livelihoods live.

Challenges such as climate change, pollution and lack of awareness of sustainable ocean management techniques place Marine resources at constant risk. These risks will limit the potential socio-economic benefits of Marine resources for future generations and even stifle the earning power of people today.

Oceans regulate rainfall and drought and account for 97 percent of the Earth's water resources, while absorbing carbon dioxide and helping to keep the carbon cycle in balance. The ocean is also a lifeline for billions of people, from food to work.

But the ocean is also a beautiful natural environment that can play a valuable recreational role. Research has shown a correlation between time spent in nature and reduced stress levels, which may be something worth pursuing.

Our oceans cover 70 percent of the world and account for 80 percent of the planet's biodiversity. We cannot have a healthy future without healthy oceans -- but they are more vulnerable than ever because of climate change and pollution.

Addressing the serious threats to our oceans means we need to work with leaders from all walks of life, from business to government to academia.