The ocean is the largest body of water on Earth. It covers more than 70% of the planet and provides a home to many species of marine plants, fish, and animals. The ocean also plays an important role in regulating climate, creating weather, and providing people with food. It absorbs 90% of the sun’s energy and distributes it globally via ocean currents, transporting heat from the equator to the poles and back again. This helps to maintain Earth’s temperature and create a global environment suitable for life. The ocean is a major source of oxygen through photosynthesis by marine plants such as phytoplankton.
The water of the ocean is salty because rain washes away minerals from rocks and soil, carrying them into rivers and then the ocean. These dissolved minerals and salts are what make up the ocean’s chemical makeup. Over time, this mineral content is slowly replenished by the water cycle.
Oceans are home to many different types of marine creatures and provide a vital source of food and water. They are also a crucial part of the global carbon cycle, absorbing and transporting carbon dioxide from the atmosphere. Oceans are also a vital economic resource, supporting coastal economies worldwide. They are the main shipping routes for goods and resources and support international tourism, which is especially important in developing countries.
Despite the importance of the ocean for human society, it is also one of the most complex and unpredictable natural systems. It is subject to both natural and human-caused threats, including the effects of climate change, pollution, and overfishing. Some of the ocean’s most significant natural hazards are hurricanes, tsunamis, and coral reef destruction. Human-caused threats include dumping of toxic waste, air pollution, and oil drilling.
The epipelagic zone, which lies between the surface of the water and the ocean floor, is where photosynthetic marine plants such as seagrass and large algae (kelp) live. These plants are similar to land plants because they have roots, stems, and leaves. They and the microscopic phytoplankton they contain produce an estimated 50-80% of all Earth’s oxygen.
The word ocean derives from the name of the Greek god Oceanus, personified as an enormous river encircling the world. The Greeks believed that the oceans provided life on Earth. This is partly true, because the oceans provide the water and mineral nutrients that support all forms of life on the planet. The oceans are also important sources of food, providing a fifth of the animal protein people consume. They also provide a significant amount of the air we breathe, absorbing and transporting carbon dioxide, and reducing both acidity and temperature of the air. In addition, living near the ocean encourages physical activity, such as walks on the beach and swimming or surfing, which help people get daily exercise, which is good for heart health, blood pressure, and cholesterol levels. It also increases the exposure to sunlight, which is essential for Vitamin D production and bone strength.