A lake near a village suffered heavy mortality of fishes within a few days. Consider the following reasons for this
(1) lost of urea and phosphate fertiliser were used in the crops in the vicinity.
(2) The area was sprayed with DDT by an aircraft.
(3) The lake water turned green and stinky/
(4) Phytoplankton populations in the lake declined initially thereby greatly reducing photosynthesis.
Which were two of above the main causes of fish mortality in the lake?

  • 2, 3

  • 3, 4

  • 1,3

  • 1,3


D.

1,3

A lake near a village suffered heavy mortality of fishes within a few days, because lots of urea and phosphate fertilizer were used in the crops in the vicinity and the area was sprayed with DDT by an aircraft, Inorganic phosphorus and nitrogen are responsible for the growth of algae. In polluted water these increase due to which algae increase greatly at the surface of water forming water bloom. Due to death of these algae, their organic matter gets decomposed due to which oxygen gets depleted and aquatic animals die.

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Global agreement on specific control strategies to reduce the release of ozone depleting substance was adopted by

  • Rio de Janerio Conference

  • The Montreal protocol

  • The koyoto protocol

  • The koyoto protocol


B.

The Montreal protocol

The Montreal protocol on substances that deplete the ozone layer is a landmark international agreement designed to protect the stratospheric ozone layer.  The treaty was originally signed in 1987 and substantially amended in 1990 and 1992. The Montreal protocol stipulates that the production and consumption of compounds that deplete ozone in the stratosphere-chlorofluorocarbons (CFCs) halons, carbon tetrachloride, and methyl chloroform are to be phased out 2000 (2005 for methyl chloroform).

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Montreal protocol aims at

  • reduction of ozone depleting substances

  • biodiversity conservation

  • control of water pollution

  • control of water pollution


A.

reduction of ozone depleting substances

In August 1989, 44 countries and EEC ratified the Montreal protocol, which provides a mechanism to review the efficiency of control measures. In a policy statement called Helsinki declaration, the attending nations agreed to phase out the production and consumption of controlled CFCs as soon as possible but not later than the year 2007. They also agreed to phase out the halons and to control and reduce other ozone depleting substances (ODSS).

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Steps taken by the Government of India to control air pollution include

  • compulsory mixing of 20% ethyl alcohol with petrol and 20% biodiesel with diesel

  • Compulsory PUC (pollution Under control) certification of petrol driven vehicles, which tests for carbon monoxide and hydrocarbons

  • permission to use only pure diesel with a maximum of 500 ppm sulphur as fuel for vehicles

  • permission to use only pure diesel with a maximum of 500 ppm sulphur as fuel for vehicles


B.

Compulsory PUC (pollution Under control) certification of petrol driven vehicles, which tests for carbon monoxide and hydrocarbons

The government of India have been taken many steps to control air pollution Out of which one includes compulsory PUC (pollution Under control) certification of petrol driven vehicles, which test for carbon monoxide and hydrocarbons.

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Chipko movement was launched for the protection of 

  • grasslands

  • forests

  • livestock

  • livestock


B.

forests

In 1973, the chipko Movement (chip koa means to hug or stick to ) was launched by Chandi Prashad Bhatt and Sunder Lal Bahuguna against large-scale felling of trees by timber contractors in the Uttarakhand hills. The starting point was Chamoli district of Garhwal region in Uttarakhand.

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