Ganges Dolphin census begins

October 12, 2019

The annual Ganges river Dolphin census is conducted by the World Wide Fund in collaboration with Uttar Pradesh Forest Department. The census is undertaken along the 250 km stretch of Upper Ganga between the Hastinapur Wild life sanctuary and Narora Ramsar site

This year tandem boat survey method is being used. Previous years, direct counting was done. This is because, the tandem boat survey method is more accurate where in the officials use two boats that move in tandem to count the dolphins. Also, this year the upstream of Bijnor Ganga Barrage has also been included.

In 2015, the count was 22 and has so far remained stable. As the animal is a mammal, it certainly has to come to the surface for breathing that helps the census to count. They are also spotted by their strange sounds when they breathe. They are also identified by detecting their high – frequency ultra sound waves.

The National Aquatic animal is important as it is a reliable indicator of the health of the river ecosystem.

About Ganges Dolphins

The Ganges Dolphins are one of the oldest creatures as that of crocodiles, sharks and turtles. They were first discovered in 1801. During its early days of discovery, the species lived in the Ganges – Brahmaputra – Meghna and Karnaphuli – Sangu river systems in India, Nepal and Bangladesh. However, it is extinct from most of its distribution ranges.

These dolphins can live only in freshwater. They hunt by emitting ultrasonic sounds. The rays bounce off fish and other prey that enables them to see an image in their mind. They dwell alone and also in groups. But the mother and calf always travel together. Female dolphins are larger than the males and they give birth once in 2 to 3 years.

It was declared the National Aquatic animal in 2009.

Threats to Dolphins

By catch

The habitat of the Ganges river dolphins is within the most densely populated areas of the world. Both fishermen and the dolphins prefer areas of the river where the fish is plentiful and the river current is slower. Hence, more dolphins die as they accidentally get caught in the fishing nets. They are also hunted for meat and oil to be used in medicinal purposes.

Pollution

Every year 9,000 tons of pesticides and 6 million tons of fertilizers are used in the vicinity of the river. River Dolphins are the top predators in the Ganges ecosystem. Hence, they tend to have high levels of toxic chemicals in their bodies that affects their health adversely.