Oceans cover around 70% of Earth's surface. This is what gives Earth the nickname the "blue planet." Oceans are very important to life all over the globe. They provide 97% of the water on Earth and produce more than half of the oxygen we breathe. They are home to more than a million different plant and animal species. One of these animals is the blue whale, the largest animal to have ever lived on the planet. Most ocean life is still is mystery, however: An estimated two-thirds of ocean life is still undiscovered. Understanding life in the world's oceans is important to helping to protect our environment and keep Earth healthy.
The largest ocean on the planet is the Pacific Ocean. The Pacific covers nearly one-third of Earth's surface and nearly half the world's ocean surface. The Pacific Ocean is home to the Mariana Trench, the lowest point on Earth's surface. At its deepest point, known as the Challenger Deep, the Mariana Trench is nearly seven miles below the surface of the ocean.
The Pacific Ocean is also home to many different plant and animal species. Located off the coast of Australia in the Coral Sea, part of the South Pacific, the Great Barrier Reef is home to more than 1,500 different fish species. As many as 10% of the world's fish species can only be found here.
The second-largest ocean is the Atlantic Ocean. It is the saltiest ocean on the planet. It covers nearly 30% of the world's ocean surface and around 20% of Earth's total surface. The Mid-Atlantic Ridge, a 10,000-mile-long underwater mountain range, extends the length of the Atlantic Ocean, from the Arctic Ocean in the north to the southern tip of Africa in the south. The Atlantic Ocean creates the highest tides on Earth, located at the Bay of Fundy in Canada. The difference between low and high tides in the bay can be as much as 53 feet!
While the Atlantic Ocean may not have the same diversity as the Pacific, the cool surface waters allow for a rich concentration of nutrients for phytoplankton. The abundance of these microscopic plants allows animal life to flourish in its waters. This makes the Atlantic a rich, fertile ocean, home to large numbers of animal species including mackerel, cod, and tuna.
Located off the eastern shore of Africa and extending along the southern coast of Asia is the world's third-largest ocean, the Indian Ocean. The Indian Ocean features some of the most interesting geography of all of the world's waters. Here, you will find more than 20 different marginal seas, straits, bays, and gulfs.
The northern Indian Ocean features a monsoon climate and is home to many strong wind patterns for the majority of the year. These wind patterns create cyclones, heavy rains, and large waves on the open waters and near the coastlines. The monsoon climate also makes the Indian Ocean the warmest of the oceans.
The Southern Ocean, also called the Antarctic Ocean, is the southernmost body of water on the planet. The Southern Ocean fully surrounds the continent of Antarctica. Ever since the borders of the world's oceans were first dictated in 1928, the border of the Southern Ocean has steadily been moved southward. Today, it is still debated whether or not the Southern Ocean is really its own body of water or just the southern parts of the Atlantic, Pacific, and Indian Oceans.
Even with its cold temperatures and dry climate, the Southern Ocean is home to several different animal species. For instance, emperor penguins make their home in Antarctica and on the sea ice of the Southern Ocean. This area is also home to sea birds, whales, and fur seals.
The northernmost and coldest ocean on Earth is the Arctic Ocean. The Arctic is also the smallest ocean on Earth. Much of the Arctic Ocean is covered by ice throughout the year, but this sea ice has been getting smaller due to climate change. This has made life harder for animals like polar bears that make the Arctic Ocean their home.
Protecting and studying the wildlife of the Arctic is important to help us understand the impact we have on the world around us and what we can do to help other species survive. The oceans of the world are full of special plants and animals that all play a role in life on Earth. The more we understand about the oceans and the species that live there, the better we can protect our world and make life better for all things that live on this planet.