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.

[UPSC Civil Services Exam – 2014 Prelims]

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1, 3 and 4 only

(d) 1, 2, 3 and 4

Answer: (c)        

Explanation:

• The decline in the population of Ganges River Dolphins cannot be attributed to the increase in the population of crocodiles in the river. Therefore, Statement 2 is incorrect.
• Human activities such as damming of rivers for irrigation and electricity generation have led to the degradation of the dolphins’ habitat and prevented their seasonal migration, making them more vulnerable to threats.
• In the last century, direct killing, habitat fragmentation caused by dams and barrages, and indiscriminate fishing have led to a drastic decline in the population of Ganges river dolphins, which now number less than 2000.
• The Ganges river dolphin, also known as ‘Susu’, was declared India’s national aquatic animal in 2009 during the National Ganga River Basin Authority’s (NGRBA) first meeting.
• Every year on April 14th, National Dolphin Day is celebrated to raise awareness about the conservation of these endangered mammals.