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.
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
Montreal protocol aims at
reduction of ozone depleting substances
biodiversity conservation
control of water pollution
control of water pollution
Chipko movement was launched for the protection of
grasslands
forests
livestock
livestock
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
