List of Ocean Plants

List of Ocean Plants
The vast ocean contains a large array of plant and animal life. According to National Geographic, the ocean covers more than 70 percent of the surface of the planet. It holds 320 million cubic miles of water. The deepest parts of the ocean may have little or no plant life. Because ocean plants need sunlight, most are either designed to float on the surface of the water, or grow on the ocean floor in water that is shallow enough to receive adequate sunlight.


Kelp (picture above) grows in cold coastal waters. It is the largest marine plant in the world and can reach up to 250 feet. Kelp is also the fastest-growing plant in the world. Kelp is typically brown and lives on the surface of the ocean. It stays afloat with the help of small flotation bulbs that support it.


seaweed on beach

Seaweed is a form of microscopic algae called phytoplankton that floats on the surface of the ocean, much like kelp.

Seaweed has been harvested by humans for thousands of years as food, material for housing, rope and baskets. It is even used as medication.

A surplus of seaweed can choke out coral reefs. Fish that eat seaweed help mitigate this problem.


sharks in seagrass

Seagrass grows in shallow water because it needs lots of sunlight. These plants have roots and live on the ocean floor. They are true flowering plants. Some types of seagrasses are turtle grass, manatee grass and shoal grass.

Seagrasses provide habitat for small fish and other young marine life such as lobsters. These animals are able to hide from predators in the grasses. Other reef fish feed on the grasses.

Red Algae

red algae

Red algae grows in warm tropical water. This plant has been growing in oceans for more than 500 million years. According to the University of California-Berkeley, red algae are red, "because of the presence of the pigment phycoerythrin; this pigment reflects red light and absorbs blue light. Because blue light penetrates water to a greater depth than light of longer wavelengths, these pigments allow red algae to photosynthesize." Red algae is harvested as food, especially in Asia. It has a high protein content and many vitamins.

Coralline Algae

anemone on coralline algae

Coralline algae consists of very fine filaments that grow over rocks. These plants may seem more like rocks than plants, and they are as hard as cement. Coralline algae helps support the structure of coral reefs.

Coral and Algae

purple coral california

Coral is not a plant; it is an animal organism. However, coral reefs get their color from the many species of algae that live on the surface of the coral. Coral polyps are translucent or white. Algae attaches itself to the coral and feeds the coral, which eats the nutrients created as byproducts of the algae's photosynthesis. Coral is also a carnivore; it has barbed tentacles that it can use to capture small fish. Though coral is an animal, it relies on a symbiotic relationship with algae to keep it alive.


Article Written By Cate Rushton

Cate Rushton has been a freelance writer since 1999, specializing in wildlife and outdoor activities. Her published works also cover relationships, gardening and travel on various websites. Rushton holds a Bachelor of Arts in English from the University of Utah.

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