When you think of seaweed, you likely think about long strands of green slimy kelp or the nori wrapped around your sushi. You may think about how it feels or smells – you likely don’t think about how it helps keep the planet alive.

Seaweed is believed to be one of the planet’s oldest organisms and has provided oxygen for our planet for millennia. There are thousands of different species that grow in a huge range of temperatures, depths, colors, shapes, and levels of salinity, all of which benefit us and the planet.

How? Read on to find out!

Seaweed, the ocean’s unsung hero, generates oxygen through photosynthesis. Floating and swaying with the currents, it absorbs sunlight using chlorophyll-rich fronds, releasing oxygen into the water as it grows. This efficient process significantly contributes to ocean oxygenation, vital for marine ecosystems. So, next time you’re at the beach, remember to thank seaweed for the fresh oxygen it provides while gracefully dancing beneath the waves.

Seaweed acts as a natural filtration system, absorbing and trapping pollutants like heavy metals, excess nutrients, and microplastics. Through bioaccumulation, it stores these substances within its tissues, effectively cleaning the surrounding environment.

Seaweed’s dense underwater forests provide crucial habitat and shelter for a wide array of marine species, such as manatees, crabs, seals, turtles, and lobsters. It serves as a nursery for young marine organisms, offering protection and sustenance during their vulnerable early stages. In essence, seaweed is a keystone species, playing a vital role in sustaining life beneath the waves.

We often think of the ocean as a separate ecosystem from our own, but this couldn’t be further from the truth. In reality, seaweed and microalgae pull carbon dioxide from the water column and release oxygen, which can then exchange at the water’s surface.

If you’ve ever had a home aquarium, you may have heard of something called an “algae bloom.” This is where algae doesn’t just grow on the glass or on rocks and ornaments, but also within the water. While this isn’t usually harmful to the fish, it does indicate that something is off-balance and the algae have been able to multiply to feed on this excess. The same thing can happen in the ocean, showing us that something we’re doing is negatively affecting the ecosystem in the water. If we’re paying attention, we can use these blooms to notice what we’re doing wrong and prevent it from happening again in the future.

Just a 9% increase in seaweed in the ocean could convert around 53 billion tons of carbon dioxide each year – that’s about the entire annual CO2 production of New York City. Seaweed’s incredible ability to help convert CO2 to oxygen has led to the proposition for “ocean afforestation”, which would be the farming of seaweed with the purpose of removing carbon from the atmosphere.

As you now know, seaweed is a much-underappreciated element when it comes to solutions to climate change and in providing ocean life with a healthy environment to live and thrive. The more people who know about its benefits, the more likely we’ll see it cared for and sustainably farmed in the future all around the world.