ECOSYSTEM (Part-I)

The reason for algae bloom is eutrophication. Due to excessive excretion of minerals and nutrients in reservoirs, these minerals are deposited at their bottom, which is the cause of eutrophication. This results in excessive growth of blue-green algae in such water bodies.

Algae come under the category of producers in the ecosystem. About 90 percent of the total photosynthesis on Earth is done by aquatic plants and algae. About 85 percent of it is in the sea (mainly by algae) and the remaining 5 percent is in the river, pond, etc. Producers make their own food by the process of photosynthesis.

Among the above options, forests, ponds, and lakes are natural ecosystems, while gardens are artificial ecosystems.

Planktons make up the upper part of the aquatic ecosystem. Phytoplankton mainly includes algae, cyanobacteria, diatoms, etc., which make their food through photosynthesis.

Microorganisms cannot decompose non-biodegradable waste. Therefore, it gets collected in the atmosphere and spreads pollution. Therefore, recycling is the best way to dispose of them, i.e., management.

These substances which contaminate the air are called ‘air pollutants. Combustion of coal, petrol, diesel, etc. mainly causes oxides of carbon and nitrogen in the air, which are the main causes of air pollution.

Carbon dioxide (CO₂) is an air pollutant, while water vapour and hydrogen gas are not included in the category of air pollutants. CO₂ gas is found in the atmosphere from 0.03 percent to 0.04 percent because all living things on the Earth give up carbon dioxide in their respiration. On the other hand, green trees take this gas while performing the process of photosynthesis, due to which its quantity in the atmosphere is controlled.

The temperature of the earth increases due to the greenhouse effect. Joseph Fourier told of the existence of the greenhouse effect in 1824 AD. The greenhouse effect is a natural process by which the atmosphere of a planet or satellite helps to warm it further.

Water vapor is the most abundant greenhouse gas in the atmosphere. The greenhouse lets the sunlight in but it does not let the heat escape. The greenhouse warms up the space similar to a car that is parked in the sun for hours. The greenhouse effect is responsible for increasing the temperature of the earth.

Pollutants that are decomposed into simple harmless substances in nature due to the action of microorganisms like bacteria etc. are called ‘biodegradable pollutants’ or biodegradable, such as cotton, paper, household waste, etc. However, materials like glass, iron, plastic, etc., are not biodegradable. That is, bacteria do not readily decompose them.