Apart from poaching, several human-induced factors contribute to the decline of Ganges River Dolphins. Construction of dams and barrages (1) fragments their habitat, isolates populations, and reduces water flow and prey availability. Getting trapped in fishing nets accidentally (bycatch) (3) is a major cause of mortality. Pollution from agricultural runoff containing synthetic fertilizers and pesticides (4), as well as industrial and municipal waste, degrades water quality and affects dolphin health and their food chain. An increase in the population of crocodiles (2) is not considered a primary driver for the overall decline of the dolphin population, although predation might occur. Therefore, statements 1, 3, and 4 represent significant reasons for the decline.
Other than poaching, what are the possible reasons for the decline in the population of Ganges River Dolphins? 1. Construction of dams and barrages on rivers 2. Increase in the population of crocodiles in rivers 3. Getting trapped in fishing nets accidentally 4. Use of synthetic fertilizers and other agricultural chemicals in crop-fields in the vicinity of rivers Select the correct answer using the code given below.
Asked in UPSC IAS 2014 · Topic: Biodiversity (Threats to Biodiversity (Habitat Loss, Pollution, Climate Change, Invasive Species, Over-exploitation))
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