Gene drives for the Ganges

The Ganges or the Ganga as its known in India is both an important symbol in Indian religious culture and a major source of water (over 25%) and supporter of local economy. It is considered and worshiped as a mother goddess in form of a fair-complexioned beautiful woman wearing a white crown with a water lily, holding a water pot in her hands, and riding her pet crocodile.


Moreover she is a symbol of fertility, abundance and purity and will even wash away your karma. The ultimate dream of every Hindu is to die in the holy city of Benaras and have his ashes dispersed in the Ganges, doing so is an easy shortcut to moksha (liberation from the cycle of life and death). Even the first prime minister of independent India, Jawaharlal Nehru, the poster boy of secularism had asked to have his ashes dispersed in the holy Ganges.


In reality the situation is quite ironic. The Ganges is one of the most polluted rivers in the world. Throughout its 2500 km route the Ganges passes through several big cities which dump lethal amounts of pollutants and fecal matter in the river. The fecal bacteria is 10-15 times more than the permissible limit. The river is flooded with heavy metals from pesticides dumped into it from industrial and agricultural activities.

Apart of pollution, the Ganges also suffers from a very hampered ecosystem due to river pollutants and increase in hydel power plants in the upper parts of the Ganges. The Ganges river dolphin, one of the only 3 freshwater dolphins left in the world is now a severely endangered species with only about 1,800 left in the entire Ganges-Brahmaputra rivers.

Dead turtle on a polluted stretch of the Ganges River, Varanasi, India.

Efforts to clean up the river have been undertaken since the past 3 decades but have yet to be fruitful. The Modi government had allocated a budget of 3 Billion dollars for the clean Ganga campaign but we are yet to see any results.

The govt has proposed a two fold plan of action, to clean the river of it’s contaminants and to rejuvenate it by restoring the ecosystem.

Another lesser known issue which has severely affected the river ecosystem is of invasive species. Foreign invasive species of fish and certain crops has damaged not only the ecosystem but also the local economy which is heavily dependant on fishing and farming. The most invasive and dangerous of this is the red bellied Piranha. This fish is native to the Amazon river basin and is alien to the Ganges ecosystem. Researches have speculated that it could have been introduced to the Ganges through boats carrying the fish for aquarium trade.

This is the space where Gene drives could play a role.

What if Gene drives could rejuvenate the dying dolphin population in the Ganges.


The Ganges river dolphin is a carnivore which can feed on invasive fish species to curb their increasing population. What if we can identify genes which result in birthing fraternal twins and drive it through the dolphin population to produce a pair of male and female dolphins? Dolphins have a gestation period of 9 months which makes it rather unsuitable for gene drives but if we can double the reproduction rate for every gestation cycle, results can be achieved much faster. Of course there will have to be way to mute the gene drive after a few generations to avoid over population.

Gene drives could also be used to curb the increasing red belly piranha population.


The red bellied Piranha breeds every year during the monsoon and lays thousands of eggs which mature in a matter of two weeks. This would be a very effective species for implementing Gene drives given their rapid breeding cycle. You could introduce Gene drives to produce only male offspring thereby curbing further increase in the population due to a lack of female mates for breeding.

The life span of a red bellied Piranha is 10 years. This is where increasing predator dolphin population come into the equation. The dolphins can pray on the remaining male piranhas thereby wiping out the entire species in a few years time.

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