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Human Uses For Seaweeds (Marine Algae)

Seaweeds Have Important Natural and Human Roles


Marine algae, commonly called seaweeds, provides food and shelter for marine life. Algae also provides the bulk of the Earth's oxygen supply through photosynthesis.

But there are also a myriad of human uses for algae. We use algae for food, medicine and even to combat global warming. Read on to learn more about the sometimes surprising uses of marine algae.


Sushi image

The most well-known use of algae is in food. Consumption of algae is obvious when you're eating nori that's wrapping your sushi roll, or seaweed on your salad. But did you know that algae can also be found in desserts such as ice cream and milk shakes, in dressings and sauces, baked goods and toothpaste? Gelatinous substances in algae are used widely in the food industry as thickeners and gelling agents. Look at the label on a food item, and if you see "carrageenan" or references to alginates or agar, then that item contains marine algae.

If you're a vegetarian or vegan, you may be familiar with agar, which can be used as a substitute for gelatin and as a thickener for soups and puddings.


Agar Plate - Y. Tambe/Wikimedia Commons
Y. Tambe/Wikimedia Commons

The agar found in red algae is used as a culture medium in microbiology research. Algae is also used in a variety of other ways, and research continues on the benefits of algae for medicine. Some claims about algae include the ability of red algae to improve our immune system, treat respiratory ailments and skin problems, and cure cold sores. Algae also contains abundant amounts of Iodine, an element required by humans and necessary for proper thyroid functioning.

Both brown (e.g., kelp and Sargassum) and red algae are used in Chinese medicine. Uses include treatment for cancer and for treating goiters, testicular pain and swelling, edema, urinary infections and sore throat.

Combat Climate Change

When marine algae conduct photosynthesis, they take up carbon dioxide (CO2), the main culprit cited in global warming. A MSNBC article reported that 2 tons of algae remove 1 ton of CO2. So, "farming" algae might lead to those algae absorbing CO2. The neat part is that those algae can be harvested and turned into biodiesel or ethanol. In January 2009, a team of UK scientists discovered that melting icebergs in Antarctica release millions of iron particles, which are causing big algal "blooms," which are absorbing carbon. The researchers will be conducting an experiment where they will release several tons of iron sulfate off the British Island of South Georgia, create a huge algae bloom and see if this is a valid technique for reducing CO2.


Some scientists have turned to the sea for fuel. As mentioned above, there is the possibility to convert algae to biofuels. Scientists in Scotland will be looking at ways to convert sea plants, particularly kelp, into fuel. These scientists would be harvesting wild kelp, which is a fast-growing species. Other reports indicate that about 35% of the U.S.'s need for liquid fuels could be provided each year by halophytes, or salt water-loving plants.

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