Ocean makes up about 71 per cent of the world. Large geographical divisions made by continents are the five oceans of the world, namely Pacific, Atlantic, Indian, Southern, and the Arctic in order from largest to smallest. The smaller water bodies include several seas, bays, gulfs, and straits.
Oceans play an important role in regulating the climate by generating tons of oxygen that we breathe and absorbing huge chunks of carbon dioxide that we release. They also support much of the world’s economy, from tourism, fisheries, to international shipping.
Oceans are the largest reservoir of water on earth, more than 96 per cent exists in the oceans. They have a highly varied topography formed by hotspot volcanoes under the Earth’s surface.
Underwater features of the ocean include continental shelf, abyssal plains, mid-ocean ridge, and ocean trenches. Surface features include coasts and islands.
What Makes The Oceans Blue?
The long-wavelength lights (red, orange and yellow) are absorbed more strongly by water than the shorter wavelength like blue light.
When white light from the sun hits the ocean surface, mostly the blue light gets reflected. Scattering of blue light, makes the ocean look blue.
This effect works if the water is very pure. If the water is full of impurities like algae or sludge, the scattered light affects the natural blue tint of the water. Let us jump onto the details of the five oceans of the world.
1. The Pacific Ocean
Between the Antarctic region in the south to the Arctic in the north; and the continents of Asia and Australia on the west and North America and South America on the east.
Challenger Deep in the Mariana Trench.
The Pacific Ocean is the deepest among all the oceans. It is also the world’s largest ocean, occupying about one-third of the Earth’s surface. It is divided into two parts, the North Pacific Ocean (in the northern hemisphere) and the South Pacific Ocean (in the southern hemisphere) by the Equator.
The Pacific Ocean covers the world’s most significant trade routes and strategically important waterways. In addition to this pollution is a major problem in the Pacific Ocean. There is a gyre of garbage in the Pacific Ocean known as the Great Pacific garbage patch.
Ring of Fire
The Pacific Ocean is famous for the area known as the Pacific Rim or Pacific Ring of Fire. It is the centre of most seismic and volcanic activities in the world.
It is the path encircling the Pacific Ocean, characterized by the world’s largest number of active volcanoes and earthquakes.
The Great Barrier Reef
The Pacific Ocean is home to the world’s largest coral reef system, the Great Barrier Reef, situated off the northeast coast of Australia.
It is located in the Coral Sea and is made up of thousands of individual corals.
Major Countries bordering the Pacific Ocean:
Vegetation and Wildlife in the Pacific Ocean
Oceanic plants provide habitat and food to fish and small animals of all kinds. Plant species include kelp, seagrass, and plankton are a few species of plants in the Pacific Ocean.
Animals like whales, dolphins, sea turtles, sea snakes, shrimp and crabs are found in the Pacific Ocean.
These can be metallic or non-metallic. Among non-metals, hydrocarbon fuels (oil and natural gas) are the most valuable. Deepwater metallic mineral deposits of manganese, cobalt, and nickel are particularly widespread in the Pacific.
Marginal Seas of the Pacific Ocean
- Philippine Sea
- Coral Sea
- South China Sea
- Tasman Sea
- Bering Sea
- East China Sea
- Sea of Okhotsk
- The Sea of Japan
- Yellow Sea
- Celebes Sea
Islands in the Pacific Ocean
Thousands of islands are present in the Pacific Ocean. Micronesia, Polynesia and Melanesia are some of these island groups. Large islands in the Pacific include:
- New Guinea
- Grand Terre
2. The Atlantic Ocean
Between North and South America on the west and Europe and Africa on the east. Between the Arctic Ocean in the north and the Southern Ocean in the south.
- Deepest Point:
The Puerto Rico Trench.
The second-largest ocean on Earth, the Atlantic Ocean is divided into two parts, the North Atlantic Ocean and the South Atlantic Ocean.
The largest sea of the Atlantic Ocean is the Sargasso Sea while the largest island is Greenland. The Atlantic Ocean has been a key route of trade and transport for ages. The Atlantic Ocean is also the hotbed for storms and hurricanes that affect North America.
The Atlantic Sargassum Belt
The motionless sea of the North Atlantic Gyre is the Sargasso Sea. This region is studded with Sargassum, a seaweed that provides habitat for many Atlantic Ocean animals.
Major countries bordering the Atlantic Ocean:
- West-African countries
Vegetation and Wildlife in the Atlantic Ocean
Sargassum, Mosses, Seagrass, Red Algae, Coralline Algae are some of the plant species in the Atlantic Ocean.
Walrus, Dolphins, Sharks, Whales, Seahorses, Seals, Sea turtles, Bluefin Tuna are some of the animal species in the Atlantic Ocean.
Potential mineral resources of the Atlantic Ocean include deposits of petroleum, sand and gravel, phosphorite, and ferromanganese.
Marginal Seas of the Atlantic Ocean
- Mediterranean Sea
- Baltic Sea
- Caribbean Sea
- English Channel
- Gulf of Mexico
- Hudson Bay
- North Sea
Major Islands in the Atlantic Ocean
- The Faroe Islands
- Canary Islands, Spain
- Tristan da Cunha
3. The Indian Ocean
Between the southern tips of Asia and Africa, Australia.
- Deepest Point:
Sunda Deep of the Java Trench.
The Indian Ocean encompasses one-fifth of the total ocean area of the globe. The third-largest of all five oceans of the world, it is the geologically youngest, and physically most complex of the world’s oceans.
The Indian Ocean remains the warmest ocean on earth, leading to a higher rate of evaporation. Over the years, Indian Ocean Region has become a vital hub of international trade and commerce, connecting Central Asia to Southeast and East Asia as well as to the Western World.
The Indian Ocean houses a few important waterways:
- Bab-el-Mandeb (Djibouti-Yemen)
- Strait of Hormuz (Iran-Oman)
- Strait of Malacca (Indonesia-Malaysia)
- Suez Canal (Egypt)
Major Countries bordering the Indian Ocean:
- Arabian Peninsula
- Malay Peninsula
- East-African countries
Vegetation and Wildlife in the Indian Ocean
Coral reefs provide feeding and breeding grounds for hundreds of marine animals and fish. The major portion of the tropical coasts is covered with mangrove forests.
Animal life includes Sea turtles and large marine mammals such as sea cows, whales, dolphins, dugongs and seals.
Minerals of potential commercial value in the Indian Ocean region include petroleum, natural gas, manganese, tin, chromite, and monazite among others.
Marginal Seas of the Indian Ocean
- Andaman Sea
- Arabian Sea
- Bay of Bengal
- Java Sea
- Persian Gulf
- Red Sea
- Sea of Zanj
Major Islands in the Indian Ocean
- Sri Lanka
- Andaman and Nicobar Islands
- Lakshadweep Islands
- Langkawi Islands
- Christmas Island
4. The Arctic Ocean
Covers the Arctic, and Borders North America and Eurasia
- Deepest Point:
The Fram Strait
The smallest of all five oceans of the world, the Arctic Ocean surrounds the North Pole. It is mostly covered by drifting ice during winter and has the coldest temperatures among all the oceans.
The low temperatures lead to a very low rate of evaporation in the ocean waters. Due to this low rate of evaporation and the huge flows of freshwater into the Arctic Ocean, it has the lowest salinity levels. Among all five oceans of the world, it is the shallowest ocean.
Major Countries bordering the Arctic Ocean:
Vegetation and Wildlife in the Arctic Ocean
The Arctic Ocean has relatively little plant life since it receives very little sunlight. During winters, the ocean is almost covered by ice, leading to a further shortage of sunlight. Still, varieties of vegetation and animals adaptable to the region, flourish in the ocean.
Arctic Ocean vegetation includes arctic mosses, lichens, plankton and seaweeds.
Animals such as whales, seals, walruses, polar bears have their home in the Arctic Ocean.
Iron ore, zinc, coal, lead, gemstones, and precious metals among others.
Marginal Seas of the Arctic Ocean
- Chukchi Sea
- East Siberian Sea
- Laptev Sea
- Kara Sea
- Barents Sea
- Greenland Sea
Major Islands in the Arctic Ocean
- The Svalbard Islands
- Faroe Island
The delicate ecosystem of the Arctic Ocean can be easily disturbed by human activities leading to climate change. The melting of large icebergs is a bitter reality check.
5. The Southern Ocean
South Sandwich Trench
Also known as the Antarctic Ocean, it is the youngest ocean of all five oceans. The Southern Ocean was recognised by the National Geographic Society.
Encircling the South Pole, the Antarctic Ocean remains covered by ice sheets and icebergs during the winters.
Countries bordering the Southern Ocean:
- South Africa
Vegetation and Wildlife in the Southern Ocean
Plants and animals adapted to the extreme weather conditions of Antarctica survive here.
The dryness and low temperatures lead to very little diversity in the Antarctic ocean as compared to other regions of the world.
Lichens, mosses and liverworts, algae, kelp and microscopic organisms make up most of the flora.
Animals in the regions include penguins, albatrosses, blue whales, sharks and fur seals.
Resources like gold, platinum, silver, copper, iron and more are yet to be exploited.
Marginal Seas of the Southern Ocean
- Ross Sea
- Weddell Sea
- Davis Sea
- Amundsen Sea
- Drake Passage
Major Islands in the Southern Ocean
- Falkland Islands
- South Sandwich Island
- D’Urville Island
- Bowman Island
- Hearst Island
Threat To The Oceans
The oceans of the world are prone to severe threats as a result of our reckless activities. The activities that we try to justify in the name of development and human welfare, ultimately lead to disruption and over-exploitation of the environment.
Let us discuss the major issues concerning the oceans.
Climate change represents the greatest threat to ocean ecosystems. It makes the oceans of the world hotter due to global warming. Dissolved oxygen levels are continuously reducing in the ocean waters, leading to breathing issues in marine animals.
Around 8 million tons of plastic are released into the oceans of the world every year. This contributes to more than 80% of all marine debris from surface waters to deep-sea sediments. This ocean plastic injures and kills marine life including fish, mammals, birds, and other organisms. Thus, the plastic that we use daily, severely damages the marine ecosystem.
Overfishing poses a major threat to ocean wildlife, livelihoods and seafood for future generations. Overfishing leads to insufficient breeding, which cannot sustain a healthy population. Once plentiful species, like bluefin tuna, are now becoming increasingly endangered. Illegal and unregulated fishing has resulted in these extreme consequences.
One-third of the global carbon dioxide emissions are absorbed by the oceans of the world. Surely this keeps our atmosphere cooler, but unfortunately, it increases the acid content of the oceanic ecosystem. This directly leads to the calcification of organisms like corals.
All these problems together contribute to a bigger issue of the destruction of the habitat of marine organisms. Coral Bleaching is an adverse impact of marine pollution. The vibrant colours of coral reefs are getting destroyed, resulting in a serious effect on coral ecosystems worldwide.
How To Protect The Oceans Of The World?
After knowing about the dangers that the global ocean faces, you might be feeling disheartened. But there are some ways we can contribute our bit to save our oceans.
We need to bring about behavioural changes to make an impact. As an individual, you can include these traits:
- Try reducing your carbon footprint by inculcating small yet impactful habits.
- Lowering the use of plastic.
- Ethical and sustainable sourcing of the seafood that you consume.
- Participating actively in beach clean-ups.
- Ensure captive propagation of the fish that you buy.
- Lending support to the organizations that are working to save the oceans of the world.
Oceans of the world are the life-supporting agents of humanity. But today the global ocean needs our support due to the increasingly negative impact of human activities on marine ecosystems.
Therefore we, as the responsible beings of this planet, are obliged to take action to avoid further loss of oceans of the world.
If you liked this article, be sure to read more articles on our website.