Life on Earth started from the Ocean. The first living things were not as complex as a one-celled organism which is already a highly sophisticated form of life. After millions years of evolution appeared single-celled organisms that lived under the water. Among these pioneers of life were the ancient algae. Blue-green algae, also called cyanobacteria were the first organisms to develop the ability to use the sunlight to form organic substances. It was a tiny autonomous system that can grow and reproduce itself, using only carbon dioxide, water and sun beams. The algae also processed fats and proteins, produced oxygen to the water, taking part in the circulation of substances. The path to the formation of multicellular forms of algae was long and difficult but from an evolutionary perspective, this should be seen as the first step towards the formation of tissues and organs.
It is quite difficult to trace the evolution of algae. Today we divide them into several groups according to their biological structure. The biggest group belongs to the Kingdom of Plants, the most ancient one to the Kingdom of Bacteria and the most simple to the Kingdom of Protozoa. There are several common features in all algae: the photosynthesis, the absence of multicellular organs and simple structure. Unlike the terrestrial plants, they don’t have so called roots and leaves, there is just the body and they never blossom or produce seeds. This is the main difference that helps us to distinguish the water plants and the algae.
Favorable climate contributed to the spread of algae throughout the World Ocean and more complex forms of it started to appear. The distribution of algae in water is largely determined by the presence of light necessary for normal photosynthesis. Multicellular red and brown algae could live deeper in the water where there is much less of sunlight. Some kinds of algae begin to feed on organic waste and dead bodies of marine animals. Thus, they help to clean the waters and boost the evolution of the other life forms. They also adapt step by step to life on land. At first, single-celled cyanobacteria started to form colonies in the shallow waters. Under the influence of the tides, small cliffs and rocks covered with algae appeared from under the surface of the water. Thanks to symbiosis with the fungus, they began to survive without water for a long time. This, in turn, contributed to the development of plants.
Algae are one of the most unpretentious organisms on Earth. They grow wherever there is access to water, sometimes in extreme conditions. In the northern seas, there are more of brown algae, southern waters contain red kinds of it. Since algae serve as food for many marine species, their distribution is limited only by the presence of the animals. Due to these factors, algae are now one of the most common organisms on the planet.
Such abundance could not go unnoticed by the humanity. As early as the 9th century BC, some folks began to use algae for food. These were mainly coastal people of Asia and Japan. It is very important that there are no algae that are poisonous to humans, so any type of algae can be eaten, except freshwater ones, which have an unpleasant taste. The huge advantage of algae over terrestrial plants is that they are rich in iodine, soda and other elements. It is proved that algae is rich in vitamins A, C and D, and also contains Omega 3 fatty acids.
The most popular edible algae is sea kale. In different cultures, it is added to salads, salted, used as a side dish, as well as the basis for the preparation of ice cream, sweets, marmalade. Islands’ inhabitants eat red and brown algae, which have a delicate taste and can be consumed raw. For Western cultures, the most famous is probably nori, which is used for making sushi and rolls. Shredded algae is also used in baking as flour. The slime extracted from some kinds of algae serves as a main source of agar. This is a gelatin substitute that is used in Asian cuisines.
Since ancient times, seaweeds that were harvested in shallow water served as livestock feed. This helped to keep livestock in the lean season, as well as saving space for pastures. Mostly these are brown algae. Also, people noticed, that the soil becomes much more fertile because of algae, so the farmers keep using it for many centuries.
The algae are not only used as food. It is proved that useful substances derived from them can be easily absorbed by the human’s body. That’s why it is widely used as a medicine in various cultures, for example in Chinese traditional medicine. Today, it is sold as a powder or a liquid extract and is quite popular among the doctors all over the world.
Industrial use of algae is also taking off. Red and brown seaweed are used for making industrial glue.
It is added to the cement and other industrial mortars to make it strong and waterproof. Japanese luminaria is rich in alginic acid, which has a huge number of applications, including the textile industry. Freshwater green algae are used for paper production. The quality of such a paper is almost the same as the paper made of wood.
It is possible to use algae in the energy sector. Historically, people were burning them instead of the wood in some cases and now we’ve started to produce the green fuel from the algae. It is a sustainable source and does not harm the environment. Sometimes this biofuel is used to heat the houses.
Another way to use the algae is cosmetology. Almost every Japanese or Korean cosmetic brand has its own product made of algae. This can be face masks, creams, balms, bath salts and so on. Maybe that’s why the Asian women always look young and fresh.
The natural ability of algae to clean water is also used on an industrial scale. While observing the algal bloom, scientists noticed that algae feel better near spillways. They accumulate everything that we think is waste and recycle it. This quality allowed us to create filters and cleaning tanks to purify the water.
Humanity has been using algae since the beginning of time, but recently we have realized their true value. They lived on the planet long before us and will stay after we are gone. That is the reason we think that there is no future without the algae.