Table of Contents
What are seaweeds?
Seaweeds can be big, small, green, brown, or red! These organisms are often single-celled and sometimes referred to as phytoplankton . They can also be larger structures made up of multiple cells, like the nori you get at the grocery store. What unites all seaweeds is their ability to photosynthesize. They’re the plants of the ocean, adept at turning carbon dioxide into sugar and energy while releasing oxygen. Seaweeds are the base of every food chain in the ocean, eaten by fish, urchins, and tiny insect-like creatures. Now, they’re being investigated as a way to combat climate change while providing us useful materials.
Humans have been harvesting wild seaweed for centuries. It might have even helped early humans on islands and coastlines survive famine and lean periods (Mouritsen et al., 2021)! The cultivation of seaweed for industrial purposes is a new idea. It’s been taking place for a few decades (Xiu-geng et al., 1999), originating in the Philippines and other parts of Southeast Asia.
The great thing about growing seaweed is that it’s super easy! The toughest part, and usually the most unsustainable part, of growing crops on land is the need for space and water. Humans are a hungry bunch, and feeding the world has led to much deforestation and changes in the way we use land. Agriculture is one of the primary uses of fresh water on land. When we plant something, something else must be removed. By contrast, the top layer of the ocean is mostly empty space. Most seaweed cultivation involves using a simple raft or rope. A small clump of seaweed is tied to the rope or raft, left in the ocean for a few weeks or months, and then harvested! There’s no need for fertilizers or pesticides either. The ocean has all that the seaweed needs.
Seaweed fuels
What if our cars, trucks, and trains were powered by plants? It’d completely eliminate the need for oil rigs or fracking. This idea isn’t entirely new. Biofuels describe a whole class of compounds that are similar to petrol or diesel, but come entirely from plant material. The most commonly used form of biofuel so far is ethanol, derived from corn or sugarcane. Ethanol fuel blends have been used in small consumer vehicles. But corn or sugarcane runs into the same problem as traditional agriculture does: where is the space?
Researchers have been diving into the prospect of using seaweed-derived biodiesel or ethanol. Growing seaweed takes a low amount of resources, and the space to cultivate feels almost infinite. Most work now focuses on using teeny-tiny phytoplankton, as this can be grown in tanks and experimented with in small scales and in labs. A lot of work is going into understanding how seaweed can be converted into energy efficiently enough to compete with diesel, petrol, and other fossil fuels (Milledge et al., 2014).
Seaweed plastics
Seaweed might be lining the shelves of your local grocery store soon, and not just because sushi is getting more and more popular. Packaging for food and cosmetics might soon come from seaweed. Glass, wood, and other materials have been steadily replaced by plastics. Plastics are usually derived from fossil fuels. Unfortunately, usually plastics aren’t biodegradable. Once they enter the environment, they stay there for hundreds of years. Seaweed-based plastics are being investigated as an alternative to fossil-fuel plastics (Pacheco et al., 2022). They don’t require the extraction of fossil fuels, and some of these biological plastics are also biodegradable! This means they are better for the environment.
Seaweed’s ability to produce long, stretchy materials also means it’s being used in fabric and textiles. Seaweed leggings and seaweed socks might not be so far off.
Seaweed superfoods
Seaweed is absolutely nutrient-packed, and contains many vitamins and minerals that are hard to come by in other sources of food. For example, seaweeds are great at absorbing iodine from the ocean (Zava & Zava, 2011). Iodine is otherwise usually absorbed from iodine-fortified salt. Iodine is crucial for some of the hormones we make in our bodies. Spirulina is one type of seaweed that’s pretty common in the market, and for good reason too! A single tablespoon contains 4 grams of protein, along with a whopping 20% of our daily requirement of Vitamin B12 (Khan et al., 2005).
Seaweed also contains a ton of fiber, and special compounds like fucoxanthin, which might even help fight diabetes and obesity (Montero et al., 2018). Fucoxanthin helps break down fat in the body. Similarly, it’s been shown to reduce cholesterol and thereby control heart disease.
Like all other foods, it’s important to consume seaweed in moderation. It is possible to eat too much and develop iodine toxicity .
The ocean is still largely unexplored. Seaweed is both one of our oldest food sources and one of the newest discoveries we’ve made! Who knows what medicines, food, fuels, or materials can be derived from the deep blue.
Flesch Kincaid Grade Level: 8.5
Flesch Kincaid Reading Ease: 55.3
Glossary
Phytoplankton: Single-celled seaweed that floats freely in water
Biofuels: Fuels that are derived from living plants
References
https://link.springer.com/article/10.1007/bf02842595
https://www.mdpi.com/1996-1073/7/11/7194
https://link.springer.com/chapter/10.1007/978-3-030-91955-9_31
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3204293/
https://www.ingentaconnect.com/content/ben/cpb/2005/00000006/00000005/art00002
https://pubmed.ncbi.nlm.nih.gov/28545377/
https://link.springer.com/article/10.1007/s10811-020-02256-4
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