Facts About Algae



  • Algae are simple organisms that live in oceans, lakes, rivers and damp mud.
  • Some algae live inside small transparent animals.
  • Algae vary from single-celled microscopic organisms to huge fronds of seaweed (brown algae) over 60 m long.
  • The smallest float freely, but others, such as seaweeds, need a place to grow like a plant.
  • Algae are so varied and often live very differently from plants, so scientists put them not in the plant kingdom but in a separate kingdom called the Proctista, along with slime moulds.
  • The most ancient algae are called blue-green algae or cyanobacteria and are put in the same kingdom as bacteria. They appeared on the Earth 3 billion years ago.
  • Some algae can multiply very quickly in polluted lakes and rivers. The thick layers can often upset the water’s natural balance and deprive it of oxygen.
  • Volvox are green algae that live in colonies about the size of a pinhead, containing as many as 60,000 cells.
  • Algae may be tiny but they are a vital food source for creatures from shrimps to whales.
  • Green algae are found mostly in freshwater. The green is the chlorophyll that enables plants to get their energy from sunlight.
  • Green algae called Spirogyra form long threads.
  • Red or brown algae are found in warm seas. Their chlorophyll is masked by other pigments.