Seaweeds: The Answer to All Our Problems?

All of us have walked through a woodland or forest filled with towering trees, crooked branches and green swaying leaves. Yet many of us never consider our underwater forests of seaweed or kelp because they are just that much harder to explore. Whilst walking in our favourite woods, I’m sure you’ve all seen the abundance of colourful wildflowers in spring, heard the unique squawks of several bird species and seen the flash of a fox or squirrel. Well, our underwater forests are just as jam packed with life as our terrestrial ones and they even hold promise for some of our greatest modern environmental challenges including climate change. Seaweed is set to become our sustainability superhero in the coming years, improving the health of not only our environment but us too.

Around the world, there are 11,000 different species of seaweed tangling themselves in mysterious cloaks of kelp, algae and marine plants. In fact, seaweed can range from microscopic pieces of phytoplankton which drift in the water column to huge kelp forests stretching up to 175 feet high; the underwater equivalent of a redwood forest. Some of these giant kelps grow even faster than bamboo at two feet per day! This is possible as many seaweeds live in pretty turbulent waters which means a fresh wave of nutrients frequently replenishes the area and provokes astonishing growth rates. Very much like a tree, they have roots called holdfasts which anchor them to submerged rocks and a stem which sprouts up towards the sky with blades being the underwater alternative to leaves. In addition though, they also have rather ingenious ‘air bladders’. These look like small balloons on the blades and they help lift the kelp up towards the surface of the sea where they gain essential sunlight.

A large variety of life on Earth depends on seaweeds with octopuses using these green and brown jungle tendrils as a hiding ground while urchins and sea stars perch around the rocky roots gathering food. Just peeking their fluffy faces above the water, sea otters hold on to the top fronds of the kelp to stop them drifting away in the currents whilst they sleep and eat. Yet humans have depended on seaweed in the past and now potentially also in our sustainable futures.

Although you may not realise it, seaweed has been used by humans as both a food source and a medicinal cure since the days of the Egyptians and today, offshore kelp farms are floating just out of sight along our coastlines. This farming is where we really start to see the benefits of seaweed and its potential as a sustainability superstar. First off, farming seaweed can overcome a lot of the environmental issues we face when growing crops. Most obviously, no land is occupied which allows green spaces to be used for some of our other pressing issues or simply left as a wildlife habitat. Seaweed also requires no chemical fertilisers, pesticides or antibiotics, all of which are increasing marine pollutants negatively impacting our oceans. In fact, seaweed itself can act as a fertiliser as it contains anti-fungal properties and improves the quality of our soil. Recent studies even suggest that by feeding cattle kelp, we could possibly reduce their gassy methane emissions.

The farming of seaweed is also great news for climate change as algae absorbs astonishing amounts of carbon dioxide which is then stored within their tissues. As wildfires around the world increase, taking away some of our most beautiful and essential forests, the ability of seaweed to absorb all our emissions is becoming more greatly acknowledged day by day. A recent study has suggested that growing seaweed in 3.8% of waters off the Californian coast would completely offset the carbon emissions created by the whole state’s agriculture industry! Another more futuristic study claims that if 9% of our global oceans were used to grow seaweed, we could harvest enough biomethane to completely replace all our fossil fuels in use. That is one amazing algae! In the future, once technology becomes more advanced, scientists believe that we could grow seaweed in industrial sized farms and once the goods are harvested, this seaweed could be sunk to the deep ocean seabed where carbon dioxide will be trapped for hundreds of years.

However, there are also practical uses we have for seaweed right now. The Maori have used seaweed for hundreds of years, sometimes to make flutes from the stems or other times they use the blades to create bags in which to preserve food. Somehow, this ancient practice has been lost along the way and we are only just rediscovering its potential as seaweed is now forming alternatives to plastic straws, wrappers and sachets. How did we ever think plastic could provide a better alternative to this all natural, fast growing, free algae?

Although it may sound rather slimy and salty, seaweed is actually a great superfood which is packed full of minerals, vitamins and antioxidants and it is already found in products you eat every day. Carrageenan is a type of seaweed which is hidden in common items from ice cream to yoghurt to vegan milk alternatives. In fact, kelp could be the new superfood about to sweep berries, kale and quinoa off supermarket shelves due to the range of health benefits eating it provides. All the benefits depend on which specie you eat, however certain algae help control blood sugar level for those with type two diabetes while others aid thyroid function. These natural remedies have been known for centuries with the Ancient Romans using this salty substance to treat wounds, burns and rashes while the Egyptians used it as a cure for breast cancer. Again, somewhere throughout history we lost these practices, however scientists are now starting to re-investigate seaweeds’ potential as a cancer cure with current studies looking promising. This gives us yet another reason as to why we should be protecting our oceans as both kelp forests and coral reefs are thought to contain undiscovered medical wonders which may help alleviate some of our most pressing health concerns.

Lastly, seaweed can also help us manage our issue of overfishing. If we increase the number of seaweed farms, we also increase the number of spaces which make a safe space for fish to raise their young which will help boost dwindling population numbers. Areas which are full of seaweed farms are also, understandably, off limits to trawling vessels which are known to decimate life covering the seabed and so we start to reduce this unsustainable fishing method even further. Finally, because of the many nutrients seaweeds contain, it can be a good alternative source of protein instead of fish which allows us to take the strain off in-demand fish stocks if we agree to switch our diets to more marine plant-based ones. In recent years, seaweed has escaped sushi bars and now also makes its way into smoothies, salads, granola and coleslaw.

Maybe now when you head to the shore you’ll feel a little differently about the brown tangle of slippery strands which stretch across the tideline. Maybe you’ll even don your wellies and run bucket in hand to collect handfuls of this wonder product. Or even your good old beach clean will help keep these underwater rainforests thriving with life whilst they secretly keep our planet ticking over in its wild and beautiful state.

By Neve McCracken-Heywood