The Ganges River dolphin (Platanista gangetica gangetica), also known as the Susu, is a rare freshwater dolphin species found primarily in the Ganges, Brahmaputra, and Meghna river systems in India, Nepal, and Bangladesh. These dolphins are blind, using echolocation to navigate and find prey in the murky river waters. Revered in Indian culture and once found in large numbers, the Ganges River dolphin is now listed as endangered by the International Union for Conservation of Nature (IUCN).
So, why are these unique and intelligent creatures disappearing from their river homes? In this article, we will explore the main threats that have pushed the Ganges River dolphin toward extinction, the human activities behind their decline, and what can be done to protect them.
A Rare and Ancient Species
The Ganges River dolphin is one of only a few species of freshwater dolphins in the world. It evolved millions of years ago and has lived in South Asia’s river systems since ancient times. Adults can grow up to 2.6 meters (about 8.5 feet) in length and weigh up to 150 kilograms (330 pounds). One of the most unusual features of this dolphin is that it is functionally blind—its eyes lack lenses, so it relies entirely on sound to understand its surroundings.
Unlike ocean dolphins that use sight, the Ganges River dolphin navigates and hunts using echolocation, sending out clicking sounds that bounce off nearby fish, riverbanks, and obstacles. This adaptation is perfect for turbid rivers—but not for all the modern changes happening in their environment.
1. Habitat Fragmentation by Dams and Barrages
One of the biggest reasons for the decline in dolphin numbers is the construction of dams, barrages, and water diversion projects. These structures block the natural flow of rivers, cutting the dolphin’s habitat into smaller, isolated sections. This fragmentation causes several serious problems:
- Dolphin populations become isolated, reducing the chances of breeding between different groups.
- Migratory routes are blocked, so dolphins cannot move to find food or mates.
- Water levels and flow patterns change, making areas too shallow or too fast-flowing for dolphins to survive.
For example, the Farakka Barrage in India has significantly affected dolphin populations by reducing water flow downstream and trapping dolphins in separate sections of the river. These barriers have reduced the dolphins’ range and forced them into increasingly smaller habitats.
2. Water Pollution
Another major threat to the Ganges River dolphin is water pollution. The rivers they live in are heavily polluted with:
- Industrial waste
- Chemical runoff
- Pesticides and fertilizers
- Sewage and human waste
- Plastic and solid garbage
Polluted water affects the dolphins in several ways:
- Toxic chemicals can enter their bodies through fish they eat.
- Low oxygen levels caused by pollution make it hard for them to breathe.
- Pollution kills fish and aquatic plants, reducing food availability.
- Direct contact with harmful substances can damage their skin and internal organs.
The Ganges River is one of the most polluted rivers in the world, and this growing toxicity is having a devastating impact on the dolphins that rely on it for survival.
3. Accidental Entanglement in Fishing Gear
Fishing is common along the Ganges and its tributaries. Unfortunately, dolphins often become entangled in fishing nets, especially gillnets. These nets are designed to catch fish, but dolphins can’t see them and may swim right into them while hunting.
Once entangled, a dolphin can drown if it can’t reach the surface to breathe. In some areas, the use of nylon nets, which are nearly invisible underwater, has made the situation worse.
In addition, many fishermen use toxic substances or electrofishing (using electric current to stun fish). These illegal methods can kill dolphins unintentionally.
4. Direct Hunting and Poaching
While no longer as widespread as in the past, poaching still exists in some areas. Dolphins have been hunted for:
- Oil and fat, which are used as traditional medicine or bait for catfish
- Meat, in some regions where demand for bushmeat exists
Although hunting dolphins is illegal in India, Bangladesh, and Nepal, enforcement is often weak, and poachers can sometimes operate without punishment. In some rural areas, old traditions or economic desperation lead people to ignore wildlife protection laws.
5. Noise Pollution and Human Disturbance
The Ganges River is one of the most densely populated regions in the world. Human activities like boat traffic, construction near rivers, and sand mining create a lot of noise pollution, which affects dolphins in several ways:
- Echolocation is disrupted by engine sounds and machinery.
- Dolphins become disoriented and stressed by loud noises.
- Breeding and social behavior can be disturbed by constant human presence.
Since dolphins rely almost completely on sound to live, any increase in noise pollution makes their environment harder to survive in.
6. Decline in Prey Availability
Dolphins feed on a variety of freshwater fish and crustaceans. Overfishing, pollution, and habitat change have caused a decline in fish populations, leaving dolphins with fewer options for food.
In some areas, local fishermen directly compete with dolphins for the same fish. If fish stocks continue to fall, dolphins will not be able to get the energy they need to grow, reproduce, and raise their young.
7. Climate Change and Reduced Water Flow
Climate change is making rivers hotter and drier in some regions. Glacial melt in the Himalayas feeds many South Asian rivers, but as glaciers shrink, river flows are becoming more unpredictable. Changes in rainfall patterns and increased temperatures can cause:
- Droughts, reducing river levels and making areas unlivable for dolphins
- Increased sedimentation, which alters habitats
- Longer dry seasons, concentrating pollution and fish in shrinking waters
Dolphins require steady, clean water flow to thrive. Climate change threatens to destabilize their ecosystem even further.
Conservation Efforts and What’s Being Done
Despite these serious challenges, there is hope. Conservation organizations, governments, and local communities are working together to protect the Ganges River dolphin.
Legal Protection
- In India, the Ganges River dolphin is a Schedule I species under the Wildlife Protection Act, giving it the highest level of protection.
- It is also recognized as India’s National Aquatic Animal.
- Killing or harming these dolphins is a criminal offense.
Ganga Action Plan and Namami Gange
The Indian government launched major efforts to clean the Ganges River and restore its ecosystem:
- Sewage treatment plants are being built to reduce pollution.
- Industrial waste management has been tightened.
- Awareness programs educate the public on protecting dolphins.
Monitoring and Research
Researchers are tracking dolphin populations using acoustic monitoring, surveys, and camera systems. Understanding their numbers and behavior helps create better conservation strategies.
Community Involvement
Local fishermen and villagers are being included in conservation through:
- Eco-tourism
- Sustainable fishing practices
- Education about dolphin-friendly living
Programs that give communities alternative sources of income help reduce the pressure on dolphin habitats.
How You Can Help
Even if you don’t live near the Ganges River, you can still support conservation efforts:
- Donate to wildlife charities working to protect freshwater dolphins.
- Reduce plastic use, which pollutes rivers globally.
- Support clean water initiatives and responsible environmental practices.
- Spread awareness about endangered freshwater species and why they matter.
The Ganges River dolphin is more than just a rare and beautiful animal it is a symbol of the health of an entire river system. Protecting this species means protecting clean water, healthy fish populations, and a balanced ecosystem for millions of people and animals.