What Organisms Eat Seaweed?

By Kevin Lee
Thousands of seaweed species are thought to exist.

It's not a true weed, but seaweed -- an ocean-dwelling, algae-based organism -- helps make life on Earth possible. In addition to releasing oxygen you need to survive, seaweed forms the building blocks of the critical marine food chain. Ocean creatures and a surprising number of other animals make seaweed part of their diet.

Seaweed's Place on the Food Chain

In the marine food chain, animals eat seaweed, predators eat those animals and people eat the predators. For example, you may dine on a lobster that ate a mingle that ingested seaweed. Because seaweed "eats" by converting sunlight into energy, it must live high enough in the ocean to receive sun rays. Composed of multicolored macroalgae, seaweed doesn't have the roots or leaves you find in regular plants. However, some fish and invertebrates seek shelter in seaweed and eat it as well.

Reptiles That Enjoy Seaweed

While some animals eat meat and others prefer plants, fungi or algae, reptiles such as the sea turtle are omnivores; they eat algae or animals depending on the species. Various types of sea turtles switch their food preferences as they age. Evidence shows that flatback sea turtles make seaweed part of their diets. Some other species, such as hawkbills and loggerheads, live in seaweed when they're young. During that time, they eat marine life they find around the seaweed -- and probably consume seaweed too.

Water-Dwelling Mammals Feast on Seaweed

Resembling tuskless walruses, manatees spend much of their lives in the water and use their flippers to gather food. Manatees are also voracious eaters, able to ingest up to 45 kilograms -- 99.2 pounds -- of vegetation daily. Their diets include various types of leaves, grass and seaweed.

Birds, Land Mammals, Seaweed and You

In addition to feasting on grains and sea grasses, the brant bird from the Arctic circle eats seaweed. The Arctic Circle is also home to the Arctic fox, an omnivore that eats small animals as well as berries and seaweed. An excellent source of A, E and other vitamins, seaweed makes a great snack or side dish for humans; people in cultures such as China and Japan have enjoyed its health benefits for thousands of years. According to the National Oceanic and Atmospheric Administration, algal products make up over 70 percent of all supermarket food, including cookies, ice cream, and beer.

About the Author

After majoring in physics, Kevin Lee began writing professionally in 1989 when, as a software developer, he also created technical articles for the Johnson Space Center. Today this urban Texas cowboy continues to crank out high-quality software as well as non-technical articles covering a multitude of diverse topics ranging from gaming to current affairs.