29 Fun, Interesting & Amazing Facts About Algae

When you think of algae, it likely conjures up images of green sludge smothering the surface of garden ponds, or slimy brown tendrils writhing along seashores. In fact, algae are responsible for creating and sustaining life on Earth, provide some of the most dramatic and spectacular natural wonders, and are proving indispensable in the fight against climate change. 

Here are 29 fascinating, surprising, and enchanting facts about the not-so-humble algae. 

• One of the oldest lifeforms on Earth, algae is responsible for the initial oxygenation of our atmosphere around 2-3 billion years ago, triggering terrestrial life on Earth. Today, algae produce around 50% of the oxygen we breathe.
• Algae are the foundations of the food chain, supporting nutritional requirements for everything from coral reefs to blue whales. Microscopic algae are consumed by tiny animals, which are in turn consumed by ever-larger sea creatures, land animals, and humans. Without algae, our planet’s many diverse ecosystems, from oceans, to jungles, to urban metropolises, would simply collapse.
• There are around 70,000 known species of algae, although researchers estimate the actual number is closer to one million! Ranging from microscopic single-cell organisms (microalgae) measuring as little as 0.2 micrometers to macroscopic, multicellular organisms (macroalgae) like seaweed and giant kelp, which can reach up to 60 meters in length. 

• Although many algae are unmistakably ‘plant-like’, they are generally classified as ‘Protists’, a group of unicellular and primitive multicellular organisms. They are neither flora, fauna, fungi, nor bacteria. Protists are mostly autotrophic photosynthesisers, converting sunlight and carbon dioxide into nutrients and energy, and releasing oxygen into our atmosphere. 
• Algae are masters of adaptability and versatility able to survive just about anywhere with sunlight and water. Found in both freshwater and saltwater, they endure vast ranges of temperatures, climates, salinities, and atmospheric conditions. They can be both free-floating, or adhered to rocks, mud, sand, and even animals.
• Each of the countless complex and diverse species of flora that exist on Earth today evolved from the rudimentary unicellular algae which first appeared billions of years ago.
• Despite supporting ecosystems, algae can also be harmful. Algal blooms, known as ‘red tides’, form when aquatic nutrients flourish, causing algal growth to explode and engulf large expanses of water, up to 1000km. This extensive algal proliferation releases harmful toxins into the water. These toxins can destabilise the marine ecosystem and cause gastrointestinal, respiratory, and neurological health problems in fish, birds, animals, and humans who consume the toxins.

• There are more individual algae living on planet Earth than there are stars in all the galaxies of our universe.
• Algae can grow up to ten times faster than terrestrial plants. Microalgae can double in size in just 24 hours. Macroalgae can grow faster than bamboo, up to 60cm in a single day.
• Phycology is the term for the study of algae. Records of human knowledge of algae can be traced back around 5,000 years to early Chinese literature, but archaeological evidence shows humans were interacting with, and consuming algae in (what is now) Chile around 14,000 years ago.
• Seaweed and kelp beds provide excellent protection against coastal erosion by displacing tidal forces before they reach land.
• Algae occupy a unique position in culinary traditions; Eaten as a staple food in Eastern cultures for thousands of years; As a poverty food providing sustenance to coastal communities in times of famine; And as a novel delicacy in luxury and innovative restaurants around the world.

• Algae is a superfood! It contains omega-3 acids which protect against cholesterol and increase dopamine (promoting mental wellness), amino acids essential for effective nutrient absorption and tissue and muscle maintenance, and high levels of iodine, essential for healthy thyroid function, which is rare in other foods. Algae also have a high vitamin and mineral content, in particular, B12, which many other plants lack, making algae a great choice for vegetarians and vegans. Incredibly protein-rich, algae produce around 4-15 tonnes of protein per hectare. In contrast, soybean typically produces just 0.6-1.2 tonnes in the same area.
• Some species of algae possess anti-cancer, anti-tumour, and anti-viral properties! Cancer therapies containing algae can induce ‘apoptosis’, eliminating the growth of harmful cells. 
• Algae has neurological benefits too! A study in 2017 found that teenagers and children with ADHD reported significant improvements in their condition after taking algae supplements for six months. 
• The cosmetics industry adds algae to many skincare products. Algae extract moisturises skin, facilitates cell turnover and renewal, promotes healthy circulation, and possesses anti-bacterial and anti-inflammatory properties.

• Sea otters use giant kelp forests as floatation devices, intertwining themselves within the long green tendrils to prevent themselves from being swept along with the tides whilst they sleep.
• Algal biofuels are a promising alternative to harmful fossil fuels. Algae can transform up to 60% of their biomass into oils, which, when extracted and refined, can be used for biodiesel and even jet fuel! Fuels derived from algae produce around 70% less greenhouse gas than fossil fuels. 
• In arable agriculture, farmers have utilised algae as a biostimulant for many thousands of years. Algae release nitrogen into the soil which can increase growth rates and crop yields by between 10 and 30%.
• Algae can be grown completely in water, minimising land displacement, as well as thriving in non-arable brackish water conditions, usually inhospitable to terrestrial crops.
• Commercial algae cultivation is known as ‘algaculture’. In 2021, the global algae market was estimated to be worth around 4.7 billion USD.

• When fed to livestock, algae offers many health benefits to the animals, such as improved fertility and immune response, maintaining healthy skin and coats, and even improving the quality of eggs when fed to poultry. 
• Algae has another, slightly stinkier use in eco-friendly agriculture. Australian researchers discovered that adding algae to cattle feed reduced harmful methane emissions from the guts of the cattle by up to 80%. Methane is the second most prevalent greenhouse gas after carbon dioxide, and livestock emissions contribute to about 44% of anthropogenic methane emissions.
• For centuries, coastal communities have used seaweeds as building materials. Seaweed’s robustness and natural pesticidal salinity has been used to thatch roofs since the Yuan Dynasty in 13th century China. Seaweed thatch is a technique still used today in areas of China and Denmark. Some of the dwellings have stood for 300 years.
• Algae exhibit one of the most magical and ethereal displays in the natural world, bioluminescence. Tiny, unicellular algae called Dinoflagellates produce breathtaking glow-in-the-dark light shows when their environment is disturbed, triggering a luminous chemical reaction. Whilst beautiful, this display is a defence mechanism to ward off potential predators. For centuries, philosophers, naturalists, scientists, historians, and even priests wondered at the cause of these spellbinding light shows. In the 17th Century, bioluminescence was thought to be the sun impregnating the sea with “an infinity of fiery and luminous spirits”. The Romans believed bioluminescence to be omens or premonitions from the Gods. Nowadays, anyone can enjoy their own bioluminescent eco-system. Small globes filled with Dinoflagellates can be purchased for as little as around £50.

• In 1954, bioluminescent algae saved the life of a fighter pilot on a training mission. The navigation system failed and all the lights went out. From the air, the pilot could see a faint glimmering in the ocean beneath him, which he correctly surmised was the bioluminescence created in the aircraft carrier’s wake. Using the glowing algae as a guide, the pilot was able to safely land on board. Conversely, bioluminescent algae have given away the secret locations of submarines and ships. In the first world war, a German U-Boat was sunk when a British ship noticed its luminous trail.
• Algae has inspired plenty of folklore and traditions. In early Far Eastern dynasties, seaweed was one of the Twelve Symbols of Sovereignty, representing purity, brightness, and leadership. Seaweed motifs were emblazoned on dynastic robes and pottery. So revered was seaweed that it was often given as gifts to the nobility. Coastal First Nations indigenous groups in the Americas anointed newborn babies with algal ointments believing that it would imbue the infant with the strength and resilience of the seaweed to withstand the pounding of the ocean tides. In Korea, it is tradition for new mothers to eat seaweed soup postpartum, as it is believed to give strength to recover from the delivery. 
• In Victorian Britain, where arts and sciences were closely intertwined, professional microscopists used tiny unicellular algae called Diatoms to create art! Each diatom has a unique form, and these were painstakingly arranged to form vibrant, intricate, kaleidoscopic patterns, visible only through a microscope.
• In 2017, the Victoria and Albert Museum in London displayed a living, breathing, functioning chandelier created from algae. Symbolising the significance of algae in our ecosystems, the chandelier fuses elegant design with innovative bioscience. Elsewhere in the arts, algae have been used to create a myriad of textiles and materials such as wood veneer, lampshades, dresses, waterproof jackets, and even sequins. Algae is touted as the next advancement towards a more sustainable material future for the arts, design, and fashion industries.

Responsible for instigating life on earth, sustaining food chains, stabilising ecosystems, challenging climate change, and illuminating oceans, algae may seem mundane, but this prehistoric organism truly is miraculous. In the words of the playwright John B Keane, “God created seaweed…The seaweed made the world”.

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