Seaweeds and Planet Health
Seaweeds are said to be the oldest organisms on the planet. Because they are underwater, and therefore out of sight (out of mind), they are largely misunderstood when compared to their land vegetable counterparts. Seaweeds have an astounding impact on our planet's health in many ways.
Seaweeds Produce Oxygen
All seaweeds photosynthesize. Scientists believe that phytoplankton (single cellular seaweeds) contribute between 50-85% of the earth's oxygen.
Seaweeds Clean and Neutralise the Ocean
Where seaweeds grow, they provide habitat for smaller ocean creatures, clean & neutralise the water and can lower the water temperature, thereby improving and restoring the ocean’s natural balance. Seaweeds add to natural ecosystems, re-mediate excess carbon dioxide and deacidify the ocean.
Seaweeds Remove Carbon Dioxide from Our Atmosphere
This figure was developed by a student at Harvard University (Hannah Zucker) and published in a 2019 blog by Sylvia Hurlimann. It shows how as macroalgae grow, they remove carbon dioxide from the atmosphere. Most of the carbon sequestered by macroalgae is sent to the deep sea either in the form of dissolved carbon or in the form of plant detritus which easily floats out to sea thanks to seaweed's gas-filled bladders.
When we think of kelp, we conjure up images of magical underwater forests. Recent research, however, suggests that in addition to creating beautiful habitats, macroalgae such as kelp play a large role reducing the effects of global warming. Kelp has an incredibly fast growth rate (up to two feet per day) and exports a large portion of its biomass out into the deep sea, allowing kelp to permanently remove carbon dioxide from the atmosphere. Removing carbon dioxide from the atmosphere will play a necessary role in preventing rising temperatures and future climate catastrophe.
Can Cultivating Seaweed Have a Positive Impact on the Planet?
Oceans cover over 70% of the earth’s surface and produce only 2% of the world’s food – this will have to change as we look to new solutions for food, and the issues with intensive farming, poor soils etc continue to grow. We know that ‘sea vegetables’ offer different nutrients from land plants and often in more highly concentrated forms. Seaweeds require neither freshwater nor fertiliser to grow, and they grow quickly. The western world is starting to realise what has been known for centuries in Asian communities – seaweeds are a remarkably valuable source of nutrition for humans (and animals). There are many studies emerging now showing a marked reduction in methane emissions from cows when they are fed seaweeds as part of their diets. This is because the seaweed supplement is so settling for their guts.
Does harvesting seaweed have a negative impact on the planet's health?
We believe anything done to extreme will have a negative impact. The key is often ‘how is it being done’?
It’s not just the food industry showing an increasing interest in seaweed. The pharmaceutical, biofuel, cosmetic, pet food and even packaging industries are increasingly looking to seaweed to solve their problems. So, we are supportive of the development of controlled ‘seaweed farms’ where seaweeds can be ethically and sustainably harvested for food and the quality and supply closely monitored to take the pressure off wild beds.
We can mitigate climate change by developing sustainable food production and reducing emissions through a move towards plant based diets.
Healthy ecosystems are critical for the earth's capacity to absorb excess carbon dioxide. Currently 25% of carbon dioxide is being absorbed into oceans leading to acidification and carefully planned and managed seaweed farms can mitigate this because coastal systems (like mangroves, salt marshes and seaweeds) have been show to soak up carbon dioxide 40x faster than tropical rain forests.