Sustainable underwater city

In this world where rising sea levels threaten the coastal communities, underwater cities emerge as an insightful solution. Sustainability isn’t just a way but the key towards life. These underwater cities aim to keep people living beneath the water for as long as possible. To achieve this ambitious dream, they need a host of special features. Here are some ideas these cities would need to make this dream a reality. 

Just like the way aquatic fauna use the oxygen dissolved in water for survival, machines can be built to use the oxygen present in water. Oxygen gets dissolved in water due to the aeration action of winds which can undergo electrolysis to separate hydrogen and oxygen the same way used in spacecrafts. The oxygen extracted from water will be used for survival but the hydrogen obtained can be used as a power source for domestic, industrial and automobile use and it unravels renewable energy. It is economically feasible and ensures its long term sustainability. 

The city requires food to feed people. The aquatic flora will serve as a nutritional basis, ensuring the health and longevity of the city’s inhabitants. The fish waste and by-products present in water provide the necessary nutrients which the plants directly absorb. For example seaweed is one of the most globally popular dietary cuisines. Special chambers can be designed which will mix the food with these nutrient sources to increase its nutritional value and is an alternative for seafood which is not eaten by everyone and is not easy to digest in the airtight environment below the water. The city under the sea would have strong, flexible buildings made to handle pressure and ocean currents. It would use turbines to get energy from tides and grow food through fish farms and seaweed. This way, it can keep going even as the sea level rises.

No one can be underwater for the rest of their lives. Thus this calls the need for a system through which people can travel in and out the water. There will be special areas designated for traveling in and out the city called moon pools (like airports) which are circular pools connected to the ocean which can be used during emergencies and to travel from one underwater city to another. Special transportation devices called Aquatic Propulsion Devices (APDs) will be present in moon pools to travel inside water and used for underwater maintenance. These will be the new generation of automobiles in the future which will replace the existing cars and bikes and do not require any non conventional sources of energy and will only require hydrogen extracted from water as a source of energy. 

One thing we should keep in mind while constructing these underwater cities is that we can’t be destroying the marine ecosystem just like we did the terrestrial ecosystem. Construction projects release dust, fumes, and heavy pollutants which can degrade aquatic life, destroy food chains and affect the quality of water. It will cause excessive sedimentation which will cause slower stream flow and rockier sea beds which mean poorer habitat for marine life.

Sustainable underwater cities are the future towards building a renewable, resilient and preserving environment harnessing aquaculture, proper water management and complete use of aquatic resources.