Ocean is a huge body of salt water that covers 70% of Earth’s surface. It’s a critical part of our planet’s ecosystem, providing food and oxygen to a wide range of living things. It also provides major transportation routes, and it’s a source of minerals and energy.
When we look at the sea, it can seem like a stagnant place. But the reality is that ocean water is constantly moving in a variety of ways. Waves and tides ebb and flow, but there is much more going on underneath the surface. Ocean currents, for example, flow like vast rivers, sweeping along predictable paths. They transport heat from the tropics to the poles and bring up rich supplies of nutrients from the depths.
In addition, the water cycle in the oceans refills dissolved minerals and salts from the land. Because of this, ocean water is saltier than freshwater. The amount of salt in a sample of ocean water can be measured by the ratio of its weight to its volume. Seawater with high salinity contains about 35 grams of dissolved minerals for every kilogram it weighs. Water with low salinity is fresher and lighter.
Another important thing to know is that the sea is a home to many different types of habitats. For instance, coral reefs are natural underwater ecosystems that support a diversity of marine life. And, the ocean is also home to some of the largest living creatures on the planet – whales, sharks, and dolphins.
People have relied on the ocean for thousands of years for food, transport, and recreation. However, oceans are facing serious threats from pollution, overfishing, and climate change.
We must work together to protect our precious oceans and all that lives in them. Fortunately, there are many efforts underway to do just that. You can help by supporting them with a one-time or recurring donation.
If you’re a fan of beachcombing or surfing, it can be fun to learn about the animals and plants you see along the shore. It’s important to know what species are safe, and which are endangered or critically threatened. And, it’s also helpful to know which beaches are protected so that you don’t disturb them.
While the term “ocean” is often used to refer to all of Earth’s seawater, geographers generally use it to distinguish the Pacific, Atlantic, Indian, Arctic, and Antarctic Oceans. Some geographers, however, believe that the word should be used to distinguish a smaller area of seawater and not all of it.