How is Kelp Different from Seaweed?

Here we discuss how Kelp is different from Seaweed

General differences

Classification: Kelp is often classified as a type of seaweed.

However, there are inherent differences between the two – in their appearance, in the number of species and their various uses. Kelp is comes under the Laminaria classification and is part of the brown algae family. There are 300 known varieties of kelp.

Sometimes they grow very densely in the ocean floor and form kelp forests. Although it looks like a plant, kelp is a Protista (assorted group of microorganisms).

Giant or Vine Kelp is the world’s longest plant and can grow to 1500 feet in height. Other types of kelp include Green Acid, Flattened Acid, Winged Kelp, Sugar, Perennial, Three-Ribbed etc.

Each type of kelp is differentiated from the other by growing habits and shape.  In some regions, the kelp available in stores is actually bladderwrack – which belongs to an entirely different family of seaweeds.

Other names under which kelp is sold are Atlantic kelp and Kelpware. Bladderwrack is used as an ingredient in various kelp supplements. The USFDA requires all products to mention if the kelp product contains bladderwrack. So, check labels carefully.

Seaweeds proliferate in the oceans and there are over 10,000 and more species of these sea plants. They are classified as algae and are paraphyletic which means that they do not come under a single multi-cellular ancestor.

Seaweeds are broadly classified into red, green and brown. Red algae have over 6000 varieties and have the highest diversity, while green algae have 1200 varieties and the lowest diversity.

While one type of brown algae is kelp, there are other types which do not belong to the kelp family like Sea Cabbage, Sea Fungus, Rockweed, Seersucker, Bottlebrush Seaweed, Soda Straws and Wireweed.

Growing areas: Kelp grows in temperatures which are < 68 degree Fahrenheit in clear, shallow waters.  Kelp grows in high nutrient waters.

The body or thallus of kelp has blades which are flat and leaf-life structures. From these grow other parts called stipes which resemble stems.

They are anchored by holdfast structures to the ocean beds – mainly coral or rock. Kelp has air-filled bladders in their body which helps to keep them afloat. They grow very rapidly, sometimes reaching 50cm in height in a day.

Seaweeds do not have specific growing areas and can survive in polar or equatorial waters.

Differences based on Uses

When kelp is burnt, we get soda ash. Alginate is a carbohydrate present in kelp and this is used to thicken various products like toothpaste and ice cream.

The rich nutrient content in kelp (like iodine) means that it is in great demand as a food and herbal supplement.  Kelp contains dietary fiber, proteins, sodium, potassium, calcium, and iron, magnesium, and beta carotene, phosphorous, vitamins A, C, B12, B1, B2, K, choline, folate and amino acids.

Seaweed is widely used to make bread, drinks and noodles. It is rich in various nutrients and vitamins. Carrageenan is a seaweed extract used in the manufacture of toothpaste and paper.

Agar also extracted from seaweed is used to thicken foods and grow bacterial cultures.   Seaweeds are also widely used as fertilizers, medicines and to manufacture industrial products.

Different types of kelp and seaweed contain different nutrients. Not all types are edible. So, check labels before purchasing either item.

Kelp can be used in place of table salt and in dishes like stir-fries, salads, soups or smoothies. Both seaweed and kelp are rich in nutrients and can be used as part of our diet. Always check with your doctor before using any of these products.