Seaweed Farming Could Be The Answer To India’s Climate Change Contribution


Author – Mahima Gad

Surrounded by water on three sides, the coastline of peninsular India takes up to 7,500 km of area. If we add inland waterways to this, it sums up to 14,500 km. Serving as a means of livelihood to a population of 14 million, coastal areas are an important component of the economy. Fishing exports alone amounted to INR45,000 crore in FY2017-18.

Occupations like fishing, cargo shipping, oil extraction, tourism, etc. use water bodies as main resources, making the marine environment crucial for humans. However, rapid industrialization, pollution, and greenhouse gas emissions are causing damage beyond repair to the environment.

Even if these industries bring revenue, they also result in large areas of water bodies, to have dissolved carbon dioxide: a major contributor to climate change. By trapping the heat emitted by industries in the atmosphere, the temperature rises, resulting in problems like acidification of water and risk to marine life.

Solution – Seaweed Farming

Seaweed, a type of algae that grows on seashores, can be a good sustainable answer to this problem. According to the research by the Central Marine Fisheries Research Institute (CMFRI) led by P. Kaladharan, seaweed farming in India can largely aid in sequestering carbon dioxide and help combat ocean acidification.

In the CMFRI experiment, samples were collected from Thotalkonda rocky beach near Vishakhapatnam and tested in the laboratory in controlled conditions, that simulated the marine atmosphere. After assessing four levels of dissolved CO2 the team inferred that among various types of algae, Chlorophyceae (green algae) comprises 70% of Indian waters, and possesses the highest carbon assimilation efficiency. If this species of seaweed is commercially produced it would help to drop the concentration of CO2 considerably.


Commercial seaweed farming in India is environmentally promising as well, since it tackles the root cause of climate change – carbon dioxide. In addition to which it can economically help the social strata affected by it the most: the fishing community. In order to carry out such a large-scale project across a 7,500km coastline in India, there would be a requirement of labor that is skilled and adapted to the coastal atmosphere. Hence, this project would provide direct livelihoods to 200,000 families in the country according to the Aquaculture Foundation of India.

A good example is the ‘Chilika model’ by Dr. Dinabandhu Sahoo who carried out seaweed cultivation in the vast Chilika Lake in Odisha, India. This project was aimed at replenishing the lagoon using seaweeds and providing livelihood to the villagers while maintaining sustainability. Like seaweed, mangroves too, are essential for maintaining the marine climate as they grow fast and help in reducing damages to the coastal areas in the event of natural calamities like tsunami.

Types of Seaweeds

Algae could be both unicellular and multi-cellular organisms, whereas seaweeds are multi-cellular. All the seaweed species generate their own food through photosynthesis, whereas some algal species rely on other external food materials. Among the seaweeds tested, Gracilaria corticata (red algae) and Sargassum polycystum (brown algae) showed 100% utilization of the dissolved CO2, but as the ambient CO2 increased in concentration from 5mg/l to 25mg/l, there was a 20% in CO2 emitted by them, in the process.

Ulva lactuca, (green alga) however showed a 100% utilization up to 15mg/l, which it reduced to 60%. Hence it was proven to be the most effective kind, with the least amount of emissions.

Advantages of seaweed farming in India

Carbon sequestration is the most impactful advantage of seaweed farming among others, because of its rapid growth rate, which is 30-60% faster than other land-based plants. Primarily, it doesn’t need extensive maintenance in the form of freshwater supply, fertilizers, etc. which is especially beneficial for India; a country on the brink of a water crisis.

Commercially around 43-300 million tons of CO2 can be sequestered if 30 million tons of seaweed is cultivated along the coastline. The net carbon that can be utilized by seaweeds along the Indian coastline is around 2895 tons per day.

Further, seaweed farming can help to reverse ocean acidification and improve the marine environment. Marine animals will have cleaner ecosystems to breed and feed – resulting in better health for themselves and for those who consume them. It is proven by a research study done by the University of California, that cattle fodder which was mixed with seaweed reduced emissions of methane – a major greenhouse gas.

The alarming rate at which the effects of climate change are manifesting themselves around the globe, seaweed cultivation shows promise of a positive change for the aquatic and overall environment in India and around the world.


The major drawback for seaweed cultivation on a large scale is the lack of awareness among people. Climate change as an issue has been rarely discussed in this country, it is overshadowed by other issues and the policymakers don’t bother taking substantial steps towards dealing with it. In addition to this, farmers who grow seaweed are unsuccessful in finding potential markets.

There is an urgent need to educate the less-fortunate and illiterate – especially people who depend on nature for their livelihoods like fishermen and farmers, as they would be the primary victim of it if required measures are not taken at the earliest.


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