The vast oceans are the largest ecosystem in the world. The oceans are home to the richest and most diverse habitat on this planet. Right from the microscopic creatures to the gigantic blue whale, an ocean biome supports the highest number of life-forms. Many scientists believe that life evolved in the ocean biome about three million years ago. The oceans are divided into four zones, each buzzing with different life-forms. These are: intertidal, pelagic, benthic, and abyssal. Due to the sheer expanse of the oceans, there exist many ecosystems based on temperature, sunlight and nutrients of a particular region. The Intertidal Zone: The area where ocean meets the land is called the intertidal zone. As the tides lash the coastal areas, this habitat is sometimes submerged in water and exposed when the water recedes. Hence, the life-forms thriving in this system are constantly changing. In high areas or rocky sea coasts, where there is less water, few varieties of algae and mollusks are found. Regions submerged for most part of the year, have varieties of algae, snails, crabs, sea stars (star fish), and other small fish in its environs. Areas exposed only during the low tides are home to many invertebrates, seaweed, and small fish. Marshy coasts contain crustaceans, crabs, or predatory birds thronging the shores. The Abyssal Zone: This is the deepest part of the ocean. There are lesser nutrients in deep waters because of the extremely cold weather, high pressure, and low oxygen content. Less amount of invertebrates and fish are found in this region. Some form of bacteria survive on minerals or hydrogen sulfide emitted due to the hydrothermal vents found deep below. The presence of these organisms initiates the food web, of which, these fish and invertebrates form an integral part. The Pelagic Zone or the Open Ocean: This area refers to the open seas which have a diverse climate. The warm and cold ocean currents frequently mix with each other causing variable temperatures. Dolphins and whales are included in this zone, along with a variety of fish like the herring and tuna. Few varieties of sharks can also be seen swimming in this region. The plant growth is limited to certain seaweeds. Many of the fish and mammals feed on plankton, which is found in abundance in this zone. The Benthic Zone: It is the area just below the pelagic zone. All types of bacteria, sponges, fungi, worms, and fish are found in this region. Seaweeds here are more nutritious. Coral Reefs and Estuaries: Besides these habitats, there are coral reefs near the US coast. The Great Barrier Reef near Australia contain corals, algae, sea urchins, octopuses, and certain fish. The estuaries support marsh grasses, mangrove trees in tropical regions, and a variety of macro flora. Worms, oysters, and freshwater aquatic birds are also found here. Ocean biomes were first thought to be endless habitats where ecosystems would continuously flourish. But pollution has reached alarming levels in the world, especially the rampant filling of the seas with hazardous waste, resulting in grave danger to these beautiful creations of nature. Coastal civilizations all over the world are responsible for the indiscriminate use of oceans as dumping zones for chemical waste, garbage, or non-decomposable matter. Coastal areas have seen a huge loss in its flora and fauna, due to the careless use of water resources. It is important to realize that a proper functioning ocean biome is the key to maintain ecological balance in nature and prevent grave problems like global warming. There are some simple steps to ensure biome protection like reducing the use of pollutants, participating in the clean-up activities in coastal areas, conserving ocean life, and gathering more knowledge on protecting the ocean world. You can make a huge difference through little efforts, just as the popular cartoon Captain Planet says, "The power is yours!".