When we are talking about climate change, there would be something missing if we don’t talk about oceans.
So, in this unit, you will be introduced to some facts related to our oceans, just so you know how important they are not just for aquatic animals that live in them, but for humans as well.
SUB-UNIT 1
What You Need To Know About Life Below Water
Did you know that the majority of life on Earth lives underwater?
People often forget that life on land only makes up a small portion of life on the planet. As a matter of fact, the majority of life on Earth can be found in our oceans. Surprising, right?
Well, actually there are still many things that might surprise you even more.
So, let’s dive into some more fun facts about our oceans
Yes, our oceans cover more than 70% of our planet’s surface. That’s about 360 million square kilometers, an area more than 36 times the size of the United States. Also, our oceans make up 97% of Earth’s water.
Besides this, the average ocean depth is about 3,700 meters. The deepest point is the Mariana Trench in the Pacific Ocean with a depth of about 11,000 meters, that’s deeper than Mount Everest is tall!
Amazingly, more than 80% of the ocean remains unexplored.
Since it’s difficult to protect what we don’t know, only about 7.91% of the world’s oceans are designated as marine protected areas. We still have a lot to discover. This just shows how BIG our oceans are.
For many of us, life underwater is mysterious, but it is actually filled with colour, life and beauty.
Our oceans are home to the greatest variety of life forms on Earth. Given so much of the Earth’s surface is underwater, it comes as no surprise that marine species outnumber those on land.
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According to the World Register of Marine Species, scientists have cataloged 240,470 accepted species, but this is believed to be just a small proportion of the estimated one million species that exist, with new marine life being discovered all the time. This goes to show just how biodiverse the world’s oceans are.
Scientists estimate that 50-80% of the oxygen production on Earth comes from the ocean. That is more than all of the tropical rainforests on land combined.
The majority of the oxygen produced is from marine algae, also known as phytoplankton which are tiny plants that live in the upper areas of the ocean and use photosynthesis to make their food. They are so abundant in the oceans that all together they account for about 50% of the photosynthetic activity and over 50% of the oxygen production on the planet.
With all the facts provided, it is evident how vital these marine environments are to the planet, and how much there still is to be explored. Thus, we can say that oceans define the planet and all lives in it.
SUB-UNIT 2
Oceans As Source Of Life
It’s not just sea creatures that depend on the ocean, we do too!
Oceans are our planet’s life support. Given that oceans’ great biodiversity, they are a source of livelihood for over 3 billion people. Oceans and fisheries continue to support the global population’s economic, social and environmental needs.
Our oceans provide natural resources including food, materials, substances, and energy. It is estimated that the goods and services the oceans provide are worth at least US$2.5 trillion per year.
If the oceans were a country, it would be the world’s seventh-largest economy. And Marine Protected Areas (MPAs) play a part in providing economic opportunities.
MPAs are the areas of sea or ocean especially dedicated to the protection and maintenance of biodiversity, natural and associated cultural resources.
For this reason, Marine Protected Areas contribute to poverty reduction by increasing fish catches and income, creating new jobs, improving health, and empowering women.
MPAs include marine parks, nature reserves, and locally managed marine areas. Thus, MPAs are like treasure mines that provide humanity with ecosystems that are extremely valuable.
Furthermore, ocean health is intimately tied to our health. According to UNESCO, the diversity of species found in oceans offers great promise for pharmaceuticals.
Oceans can also be an ally against COVID-19 – bacteria found in the depths of the ocean are used to carry out rapid testing to detect the presence of COVID-19.
Additionally, marine fisheries provide 57 million jobs globally and provide the primary source of protein to over half of the world’s population in the least developed countries.
For all the reasons above, oceans, seas and other marine resources are essential to human well-being as well as social and economic development worldwide. Therefore, conserving and sustainably using the world’s oceans, seas and marine resources are strongly needed.
Perhaps the most critical role our oceans play is regulating the climate by absorbing heat and carbon dioxide (CO2) from the atmosphere. They absorb about 30% of the carbon dioxide that humans produce, making them one of the world's largest 'carbon sinks' and helping to reduce the impact of climate change. In the next unit, we’ll explore more about the critical role oceans play in the fight against climate change.
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References
UNEP | Biology Dictionary | World Expeditions | Togetherband | Trafalgar | UN | TED