The Ocean – The Earth’s Largest Living Organism

The Earth’s largest living organism — a vast body of salt water that covers more than 70% of the planet’s surface and contains countless plants, animals, and other species. It’s also a critical climate regulator, soaking up and dispersing energy (heat) from and to the rest of the world and recycling nutrients and carbon dioxide throughout our planet’s ecosystems.

The ocean is constantly changing, from the sunlit surface layer called the epipelagic zone to the dark, unseen mesopelagic zone that extends down thousands of feet. This dynamic ocean environment supports a diversity of marine species, from microscopic algae to the largest animal that has ever lived, the blue whale (Balaenoptera musculus).

Water in the ocean is hotter at its surface than in deeper layers, and it’s lighter or more buoyant at the surface than in lower depths. These natural properties give rise to the powerful and mysterious ocean currents that transport heat, food, and marine life around the globe — a system known as the thermohaline conveyor belt.

Warm surface water is constantly mixing with colder deep water and bringing up new nutrients, a process known as upwelling. This cycle sustains the productivity of some marine ecosystems and fisheries, as well as helping to regulate our planet’s climate by moving heat from equator to poles.

As the water mixes and evaporates, it leaves behind salt, so seawater is generally saltier at the surface than in deeper layers. This naturally occurs, but human activities also contribute to ocean saltiness by disposing of waste waters and introducing chemicals from industrial production processes.

Although humans depend on the ocean for a variety of goods and services, our actions are harming this vital habitat. For example, as we consume more fuel, the oceans are absorbing more and more heat and transforming into a more acidic place.

The best way to save the ocean is by educating ourselves on the issues that affect it. This knowledge can motivate us to change our behavior, for example, by reducing our use of fossil fuels. Other ways we can help include becoming a sustainable seafood shopper and supporting organizations that work to preserve marine life. By making these simple changes, we can ensure the future of our planet’s most amazing living organism — the ocean.

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