Algae - Precursor of Life on Earth

Scientists point out to the importance of single cell algae; they produce more oxygen than all land plants combined. And their use as food to augment limited food supply opens a new field of farming, including future space travel. Algae hold the key in cleaning up our wastes, a process called bioremediation.

Dr Abe V Rotor

   

Understanding the living world of minutiae. Summer Workshop for Kids conducted by the author. Lagro, QC

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Photomicrographs of Spirogira

 

 

Mass of Spirogyra 

 

Volvox - Colonial alga

Spirulina Farm

Algae belong to two Kingdoms in the phylogenetic tree of living things: Kingdom Monera (Green Algae) and Kingdom Protista (Blue-Green Algae or BGA). The BGAs or Cyabobacteria, are among the earliest organisms on earth and virtually have not changed. They are often referred to as living fossils.  

Algae of the moneran group such as Nostoc, Spirolina, Anabaena Ocillatoria grow into communities; they form into mass  rich in nutrients for pant growth (eg Nostoc), grow in association with plants (Anabaena in symbiosis with Azolla fern), or form composite communities. 

Algae being the first photosynthetic organisms, did not only provide the food base of a prototype food chain, but increased the oxygen level of the air vital to animals under the principles of Oxygen-Carbon Dioxide Cycle, and Organic-Inorganic Cycle as well.

Algae of the protist group or the green algae, populate the lighted layer of the ocean comprising the phytoplankton, that feed the zooplankton (microscopic animals), which feed the small fish, the large fish in this order, onto our dining table. Since 70 percent of the earth's surface is water, more food and oxygen are produced than on land. 

Algae are prolific; under favorable conditions undergo algal bloom.  While generally beneficial, excessive and continued algal bloom disturbs the ecosystem, renders  water unfit for human use, Deprivation of oxygen and buildup of CO2 and other gases leads to fish kill, and Red Tide.  

Algal bloom of certain dinoflagellates called Red Tide occurs in estuaries in many parts of the world, toxic to fish and other marine life, and humans causing paralysis and even death.  The toxin accumulates in mussels, oysters, crustaceans, when ingested may cause paralysis called PSP.  

Algae are soil builders, agents of weathering of rocks, pioneers in converting wastelands, setting favorable conditions for the growth and development of plants and other organisms, leading to the formation of ecosystems. 

Algae comprise the base of food pyramids in ponds, lakes and oceans.  They are the link of the inorganic and the organic world, capturing the sun's energy through photosynthesis.  From hereon, different organisms depend for their food on the main and by-products. 

Algae in their macroscopic forms - the seaweeds - make the forests of the sea. They grow into enormous size and volume on coral reefs, these are the counterparts of the forests on land, particularly the rainforest.

Marine algae or seaweeds are divided into three groups: Brown Algae (Phaeophyta, eg Sargassum), Green Algae (Chlorophyta eg Caulerpa, Codium). Red Algae (Rhodophyta, eg Porphyra). Seaweed farming has developed into a major industry for their many uses in food, medicine, agriculture and industry.  (PHOTO: Euchema, Chlorophyta)

Fossil of diatoms (PHOTO), a division of algae under Chrysophyta, called diatomaceous earth is mined for many uses particularly as filters and ingredients of toothpaste, cosmetics, pesticide, etc. It is important in the food web since many organisms need the element for their development. Diatoms have excellent patterns and designs that inspire artists and builders.

Algae form thick mats and layers on land, fertilizing the land in the process, and protecting it from destructive elements such as sudden changes in temperature, erosion, desiccation and the like, vital in keeping environmental balance.