A Primer on Seaweed — Don’t Call it a Plant!

We’ve all heard the optimistic expression, “there are plenty of fish in the sea,” but what you might not know is there’s a boatload of seaweed out there, too. In fact, among the three main categories of these multi-cellular algae — red, green and brown — there are just about 10,000 varieties in that vast ocean.

No one has performed an accurate head count, of course, but again, that’s a lot of seaweed. And yes, seaweed is an algae. The actual term “seaweed” is just an informal description of this organism. And whatever you do, don’t call it a plant! You’ll have marine biologists shuddering in horror.

While they’re not plants, all seaweed share one important element with plants, trees, shrubs and other greenery: They all produce their own meals the same way. Seaweed and plants make food by converting energy from the sun into carbon dioxide from the air.

That’s why you don’t find seaweed deep on the ocean floor. Where you do see this algae is either floating on the surface of the ocean — sunbathing, if you will — or in shallow waters where the sun can still reach it. As it turns out, most seaweeds reside within 300 feet of the ocean surface.

In fact, there are only three environmental elements that distinguish seaweed, and you can probably guess the first criteria — the presence of seawater (OK, brackish water in some instances). The second is the presence of enough sunlight to drive the aforementioned photosynthesis. A third common requirement is a firm attachment point.

What are the differences between the three seaweed groups? One difference, obviously, is the pigments contained in their cells — thus the descriptions of green, red and brown.

Green seaweeds are the least common in the ocean, and they live in the shallowest waters, including tide pools or where the ocean and freshwater mix — such as the mouth of a river. They like tropical, warm waters and they inherit their color from an abundance of chlorophyll.

Red seaweeds on the other hand, reside in the deepest waters and don’t mind the cold at all. Their pigment distinguishes them in reds, pinks and purples, and their small, branchy appearance confuses some folks who erroneously think they’re a form of coral.

But by far the most common seaweed — the one you’ve most likely seen lying on the beach or floating offshore in paddies, are brown seaweeds, sometimes called kelp or rockweed. In fact, kelp is often described as “fish hotels” because finned marine animals like to hide in its protective forest-like environment. Brown seaweed has gold or brown pigments that mask the chlorophyll.

And it’s the brown seaweed that holds the most interest for us here at The Seaweed Bath Co. We use Bladderwrack — a form of brown seaweed — in most of our all-natural seaweed products. Among many other benefits, brown seaweed features amino acids that can hydrate dry skin and reduce the flaking, scaling and redness that’s often associated with skin conditions such as psoriasis and eczema.

We choose to use Bladderwrack in our products, and we’ll give you more reasons why in a future post.


Leave a comment

Please note, comments must be approved before they are published

Previous Post

Read the article

Learn about our company

Read Our Story