9 of the most fascinating uses for Seaweed

Update: 11/23/2012


     Most people call the plants that you commonly see under your feet washed up on the beach or on rocks below the watertime all along the coast; seaweeds – sea vegetables.

    Seaweed is a term used to refer to a wide array of marine algae. For ages, human civilizations all across the globe have used seaweed for everything from sustenance to agriculture. With modern science, the usesage of seaweed have only multiplied, and is another reminder as to the importance of protecting our oceans and the vast valuable resources they are home to.

      Have a look at 9 of the most fascinating uses for seaweed, and vote for your favorite!

Food Additives

     It’s very likely that you eat seaweed on a regular basis without even knowing it! Alginate, carrageenan, and agar are extracted from seaweed and used in a wide variety of food products for many different purposes. Seaweed keeps ice cream smooth and creamy by preventing ice crystals from forming when freezing, and actually slows down the speed at which ice cream melts. It is used in beers for a more stable and lasting foam, and in wines to help clarify the color. It is also used to thicken and stabilize everything from sauces, syrups, and soups to mayonnaise, salad dressings, and yogurt.

Cooked Food

     In addition to being a beneficial additive for many modern food products, seaweed has an ancient history as a more fundamental food source, both raw and cooked. While still regarded primarily as a health food in the west, Japan, Korea, and China have used seaweed as a dietary staple since prehistoric times. The plants are often dried and either powdered or cut into strips. Many species, like kombu, are used in preparation with numerous fish, meat, soup, and rice dishes. Records from Scotland and Ireland indicate that a native seaweed, dulse, has been collected since at least the 7th century, which is dried and eaten like potato chips, and served as pub food in some places. In Wales, a seaweed known as laver is used in a variety of traditional Welsh dishes, such as laver bread.


       With the copious health benefits that seaweed provides, it’s no wonder it has so many dietary functions. Seaweed extracts an amazing amount of nutrients from the ocean, and is most notable for its extremely high iodine content, able to exceed daily recommended values in just one dried gram of even the least potent species. Seaweed is also one of the richest plant sources of calcium. Some species, like nori, have a high protein content. Nori also has a vitamin C content 1.5 times that of oranges. Seaweed has other vitamins, like B12, and various species are rich in carotenes. Seaweed also has very little fat and a high fiber content.

Cosmetics & Bath Products

     The same seaweed extracts used in food are also common ingredients in lotions and creams. Seaweed is used as a stabilizing agent in toothpaste. Seaweed is also used in soaps and shampoos, and in addition to its function for gelling various substances together is said to have beneficial effects on the skin, such as anti-aging. These claims, however, are not yet substantiated by science.

HPV Prevention

    Many sexual lubricants use the seaweed extract carrageenan to thicken their products. Research has found that this seaweed extract is extremely effective at preventing HPV, the most common sexually transmitted infection in the United States, and the source of most cases of cervical cancer. Seaweed was also found to be somewhat effective against HIV and herpes, but was 1000 times more effective against genital HPV.


      Most biofuel is produced from sugar cane and corn, and many people argue that to produce the desirable amount of fuel would detract too greatly from land that could be used for food, leading to food shortages and higher grocery prices. Ongoing research has been conducted into the use of seaweed as a biofuel. Seaweed grows much more rapidly than other biofuel sources, is cheaper and easier to produce, and will have no effect on food supplies. Scientists are still working to find ways to increase the efficiency of mass seaweed production so that it can become a viable commercial biofuel.


       Seaweed has a vast history of being used for fertilizer by coastal populations all over the world. In most locales, large brown seaweed that has been cast adrift on beaches will be collected for use on nearby crops. Wet seaweed is heavy, so rarely travels very far inland, but more recent seaweed fertilizers have been commercialized with dried seaweed or seaweed extracts. Seaweed has a suitable nitrogen and potassium content for fertilizer, and its large amounts of insoluble carbohydrates are great for retaining moisture and conditioning soil, as well.

Wastewater Treatment

      Seaweed has a lot of potential in cleaning up wastewater. Seaweed can effectively reduce phosphorous and nitrogen content (such as ammonium) from the discharge of sewage treatments and agricultural runoff. The high levels of chemical nutrients polluting these waters can lead to eutrophication, the unhealthy over-production of an ecosystem, something which seaweed can help curb. Seaweed is also effective at absorbing metals. When alginate has already been extracted from seaweed, the waste product that is left can be used for this purpose, further increasing the productivity of the plant. European researchers were able to use seaweed to remove up to 95% of metals in water being discharged from mines.

Seaweed Baths

     Seaweed baths are a popular phenomenon in Ireland. Though not nearly as fashionable today as they were a century ago, there are still many who swear by their health benefits for the treatment of ailments like arthritis, rheumatism and various skin conditions. Seaweed baths are said to detoxify the body, but rather than merely dehydrating it like a steam bath would, they rejuvenate it with a plethora of minerals. As with the medical assertions of its use in cosmetics, the health benefits of seaweed baths are not scientifically supported at this time.

    Seaweed grow in every sea ocean around the world, from the equator to the Artic, vast beds of seaweeds grow from just above the beach line to the absolute limits that light can reach. They are a vast and diverse group of ancient aquatic plants known as algae. It is no wonder then that men use of seaweeds and the impact they almost certainly have made on our ancestors lives, in ancient, extensive and considerable.




Back to Top