VPE 511: Environment and Environmental Hygiene (2+1)

EFFECT OF MARINE POLLUTION

Eutrophication

• Domestic sewage contain large amount of phosphate, nitrates and other nutrients and thus it become nutrient rich. The water bodies become highly productive or eutrophic and the phenomenon is known as eutrophication. It stimulates the luxuriant growth of algae in water. It competes with other aquatic forms, leading to depletion of oxygen. The plants starts taking in oxygen and giving out carbondioxide and hence a situation of oxygen deficiency created and animals die.
• Further the algal growth releases some toxic chemicals which kills fish, birds and other animals, thus water begins to stink.
• In 1965, Lake Erie (USA) more than 80 tons of phosphate added daily. Each 400 g phosphate encourages about 350 tons of algal slime. This growth appeared as big mounds, clogging pipes and interfered fishing and navigation.
• Organic pollution causes excessive multiplication of harmful organisms and the consequences will be passed on to human being eventually.
• Hence metals, chlorinated hydrocarbons, DDT, etc get accumulated in marine food and its products and finally reached to man and animals by food chain.
• The oil spread due to oil spills forms a surface layer over water for several hundred square kilometer, which prevent the oxygen dissolution from the environment and hence marine living being die due to lack of oxygen.
• Radioactive nuclei having half life period with several million years are get in to mineral deposits or other living organisms. As the radiations are harmful which leads to many type of cancers in man and other animals.
• Heat causes local ecological imbalance in energy flow and biological equilibrium . In tropical countries animals live little lower than the lethal limit and increase in temperature leads to distress of even death.