Aquatic Pollution and Coastal Management

Unit 1 : Classification of aquatic pollution

1.1.Origin and Development of Biosphere

According to some schools of thought, perhaps 3000 – 4000 million years ago, the world was very ‘hot’, very ‘pure’ and very ‘sterile’. As it cooled, some 1000 million years later, the surface of the earth contained sand, clay and limestone; the hydrosphere contained H₂S, NaCl, KCl, KH₂PO₄ and NH₄HCO₃ in lower concentrations and above there circled an atmosphere of CO₂, CH₄ and N₂ with very little H₂S and water. With time, perhaps aided by energy from short wave sunlight, N₂ increased, CO₂ decreased and CH₄, NH₃ and H₂S disappeared. In the lithosphere FeS was produced and NaCl became dominant in the hydrosphere and amino acids in traces were formed. Later, visible light possibly acting on metal elements led to the formation of FeO(OH) and CaCO₃ ,and peptides, pyrimidines, purines and pentoses. The pure earth was being organically polluted and eventually cobionts became organelles.organelles became organisms and then protozoa. In a sense, this is pollution in the shape of the introduction hitherto unknown substances (organic molecules and solids) pollution had culminated in the appearance of primeval forms of life.