India's river supporting high level of biodiversity , including globally endangered species such as the country's national aquatic animal , the Ganges river Dolphin - the fish - eating crocodile - the gharial and the numerous freshwater turtles ,fishes and birds.

Introduction:
The Ganga river, also known as the Ganges, is one of the most polluted rivers in the world due to various human activities. This pollution has had a detrimental impact on the biodiversity of the river, affecting numerous animal species that depend on its ecosystem for survival. Here are two examples of animal biodiversity endangered by the pollution of the river Ganga:

1. Gangetic Dolphin (Platanista gangetica):
The Gangetic Dolphin, also known as the South Asian River Dolphin, is one of the most iconic and endangered species found in the Ganga river. The pollution of the river has significantly impacted the population and habitat of these dolphins. Here's how:

- Water pollution: The Ganga river is contaminated with various pollutants, including industrial waste, sewage, and agricultural runoff. The high levels of toxic substances, such as heavy metals and pesticides, have led to a decline in water quality. Dolphins are highly sensitive to changes in water quality and are prone to health issues and reproductive problems as a result of the pollution.

- Loss of prey: The pollution of the river has led to a decrease in the availability of prey species for the dolphins. The excessive use of pesticides in agricultural practices has led to the death of fish and other aquatic organisms, reducing the food sources for dolphins. This scarcity of prey has resulted in malnutrition and starvation among dolphins, further endangering their population.

- Physical injuries: The presence of solid waste, particularly plastic, in the river poses a significant threat to dolphins. Dolphins often get entangled in plastic debris, leading to injuries and even death. They may also accidentally ingest plastic, causing internal blockages and organ damage.

2. Gharial (Gavialis gangeticus):
The Gharial, also known as the fish-eating crocodile, is another species at risk due to the pollution of the Ganga river. The following factors explain how pollution affects their survival:

- Decrease in fish population: The Gharial primarily feeds on fish, and the pollution of the Ganga river has resulted in a decline in fish populations. Industrial waste, sewage, and agricultural runoff have contaminated the river, leading to the death of fish and other aquatic organisms. The scarcity of food adversely affects the survival and reproductive success of Gharials.

- Egg and hatchling mortality: Gharials lay their eggs on riverbanks, and pollution has a negative impact on the nesting sites. The increased presence of pollutants in the soil and water affects the viability of the eggs and the survival of hatchlings. Pollution can disrupt the natural incubation process and lead to deformities or death of the embryos.

- Chemical contaminants: The pollution of the Ganga river introduces various chemical contaminants that are harmful to Gharials. Pesticides, heavy metals, and other toxic substances accumulate in the tissues of these reptiles, leading to health issues and reduced reproductive success. These pollutants can disrupt the hormonal balance, weaken the immune system, and cause long-term harm to the Gharial population.

Conclusion:
The pollution of the Ganga river poses a significant threat to the biodiversity of the ecosystem. Animals like the Gangetic Dolphin and Gharial are particularly vulnerable to the adverse effects of pollution. Efforts to reduce