The miracle of algae

When you think of marine algae, you probably picture slimy brown, red or green tendrils washed up on beaches or attached to rocks. Some of these seaweeds grow in saltwater ocean "forests," others are at home in brackish or freshwater. They provide both a home and food to marine animals. But some algae are microscopic. Despite their tiny size they are essential to life on earth.

Microscopic algae, such as phytoplankton, are at the base of most marine food chains. Without them we might not even be here. Most are single-celled organisms that photosynthesize. They produce around half of the world's oxygen today.

When the temperature is right and there is an overabundance of nutrients in the water, algae can multiply quickly, resulting in a bloom. These blooms are often harmless but sometimes they can reduce oxygen levels in the water, killing marine life.

Coastal peoples have been using seaweed for centuries. It was so important in Ireland, for instance, that 31 words exist for it in the Irish language. That's because the organisms can be used in many ways. Sustainable seaweed farming is now seeing a renaissance globally. It requires no fresh water, arable land or fertilizers and the seaweed acts as a carbon sink.

Perhaps the best known seaweed meal is the sushi roll. For more than a thousand years, Japanese people have been wrapping fish, rice and vegetables in a seaweed called nori. But you can also use this highly nutritious food in salads and other dishes. Some companies even manufacture seaweed spaghetti and noodles.

Many types of seaweed have anti-inflammatory and anti-microbial properties and have been used for treating wounds and burns for thousands of years. Scientists are now investigating the use of seaweed in skin regeneration as well as seaweed-derived compounds in treating certain types of cancer.

Seaweeds are also used as binding agents in food and other products like toothpaste. But perhaps one of their most popular current uses is in organic cosmetics and skincare products — that's a far cry from the slimy tendril floating in the water.