Seaweed is found throughout the world's coastal regions, but what exactly is it? The name is misleading as it's not a 'weed,' but a prolific form of sea vegetation that is vital to life. Collectively, seaweed supplies a large proportion of the world's oxygen and plays a vital role in removing carbon from the atmosphere. It's also full of beneficial nutrients and, in some cultures, is a staple part of people's diets.

But what is it? The term 'seaweed' is a general term that refers to thousands of varied species of macroscopic, multicellular marine algae. Aside from its benefits for humanity, seaweed also provides essential nursery habitats for juvenile fish and other forms of marine life. There's much more to humble seaweed than meets the eye, and to give you a glimpse, here's our top ten seaweed facts...

Sea Lions in Kelp

1. There Are Over 12,000 Species of Seaweed

With so many different species of seaweed, you shouldn't be surprised to hear that it comes in a huge array of shapes and sizes. California's iconic giant kelp forests sit at one end of the scale, and sailor's eyeball seaweed, at the other end, couldn't be more different looking. Sailor's eyeball is a spherical single-cell organism that, well, resembles an eyeball.

2. Seaweed is Neither a Weed Nor a Plant

In terms of scientific classification, seaweed is neither a plant nor a weed. Seaweed falls into one of three categories of algae: Rhodophyta (red), Phaeophyta (brown) and Chlorophyta (green) algae. On the other hand, seagrass, a turtle's favourite snack, is not seaweed but a true plant.

Fish and Seaweed

3. Seaweed Provides Food and Shelter for Marine Organisms

Crabs, shrimp, urchins and many species of juvenile fish use seaweed to escape the clutches of their predators. Seaweed provides excellent nursery conditions for some species, and it plays a vital role in the marine ecosystem, similar to the way mangroves provide a safe haven for growing marine life.

4. Seaweed is Eaten in Many Countries

Seaweed can be a valuable source of nutrients for both humans and some marine species. In many cultures, seaweed is farmed and used in local cuisines. The best-known example of this is Japanese sushi, which uses dried seaweed (nori) to wrap sushi rolls.

In other cultures, seaweed is incorporated into soups, stews and salads, and in Wales, is even used to make laverbread. Laverbread is made from laver seaweed, which is a type of red algae.


5. Seaweed Can Grow Extremely Quickly

Giant kelp, in particular, grows extremely quickly. When conditions are ideal, giant kelp has been known to grow up to 18 inches per day. Areas famed for their giant kelp forests, such as California and southern Oman, work hard to protect these subaquatic forests as they play an important role in producing oxygen and absorbing carbon from the atmosphere.

6. Seaweed Can Taste Like Bacon

If the idea of eating red algae seaweed doesn't immediately grab you, what if we told you that red algae can taste like bacon? A company has developed a plant-based bacon that is made almost entirely from red algae seaweed. Just don't forget to take a bottle of HP sauce on your next dive trip...

Seaweed Farm

7. Seaweed is Farmed in Many Countries

Our growing appetite for seaweed has led to a rise in seaweed farms. Rather than rely on the unpredictability of nature, lines are set in shallow water and seaweed is cultivated along the lines. Nusa Penida and Nusa Lembongan, off the southern coast of Bali, both have seaweed farms along their coastlines, and the industry helps support the local communities.

Seaweed is also farmed in Zanzibar, Tanzania, where, among other uses, seaweed is used to make natural soap, scented with exotic herbs and spices. If you're in Zanzibar to experience the epic diving, pop into the Zanzibar Seaweed Centre and grab some seaweed soaps.

8. Seaweed Has Medicinal Properties

Seaweed is packed with vitamins and nutrients, including iodine, iron and various antioxidants. This has led to the application of seaweed in medicine, with scientists researching the usefulness of seaweed to treat various immune system issues, respiratory ailments and skin problems, as well as cold sores and the HPV virus treatments.

Ghost Pipefish

9. Ghost Pipefish Can Perfectly Mimic Seaweed

Certain marine species use seaweed to hide from predators. Some, such as the robust and halimeda ghost pipefishes, are able to mimic the appearance of certain seaweeds and spend much of their life swaying in the shallow ocean surge. Next time you swim past a small frond of seaweed, take a moment to make sure it's not harbouring a sneaky ghost pipefish.

10. Sargassum Seaweed Is Worth Checking Out for Marine Life!

Sargassum seaweed, a type of brown algae, lives a planktonic existence, free-floating across the ocean's surface. Next time a patch of sargassum floats past, have a little look inside as you may find a pleasant surprise. There's often shrimp and crabs hitching a ride, but occasionally, you may also be lucky enough to discover a sargassum frogfish staring back at you.

If you enjoyed reading this blog, you may also like our Top Ten Snapper Facts, Top Ten Mantis Shrimp Facts and Top Ten Bull Shark Facts