Blue-green algae

Cyanobacteria, also known as blue-green algae, are a group of photosynthetic microorganisms that are found in a wide range of aquatic environments, such as rivers, lakes, and oceans. They are considered to be one of the oldest forms of life on Earth, and have been around for more than three billion years.

Cyanobacteria are capable of performing photosynthesis, which means they produce oxygen as a byproduct of photosynthesis. This ability to produce oxygen is thought to have played a major role in the evolution of the Earth’s atmosphere.

Cyanobacteria occupy a wide variety of ecological niches in aquatic environments, from freshwater to saltwater, from cold to hot environments, from acidic to alkaline waters, and from deep waters to shallow waters. They can form a wide range of associations with other organisms, from mutualistic symbioses to parasitic relationships.

Food chain & uses

In the food chain, cyanobacteria can be primary producers, meaning they are at the base of the food chain and provide energy to other organisms through photosynthesis. They are consumed by many aquatic organisms, including zooplankton, aquatic insects, and fish, which in turn are consumed by larger aquatic animals and birds. Cyanobacteria can also form symbiotic relationships with certain organisms, such as lichens and certain types of coral.

Cyanobacteria are also important to humans as they are used in several ways. They are used in agriculture as a natural fertilizer, they are used in the production of biofuels and they are used in the production of certain types of food such as spirulina and some types of blue-green algae supplements.

However, cyanobacteria can also have negative impacts on human health and the environment. Some species of cyanobacteria can produce toxins, such as microcystins, which can cause liver damage, skin irritation, and even death in severe cases. These toxins can accumulate in seafood and shellfish, creating a danger for human consumption. Cyanobacteria blooms can also lead to the formation of harmful algal blooms (HABs), which can make the water unsafe for swimming, fishing and other recreational activities.