Sustainable development is a coherent way to deal with current universal challenges such as climate change, environmental degradation, and resource depletion. Nevertheless, the basic principles of recycling to be sustainable as a solution should be met when converting from a fossil-based economy to a bio-based economy. The bio-based economy's suitable capacity should be kept open when examining the new feedstock potentialities as the downward approach would escalate value creation. Seaweed, a bio-product, has unique chemical properties, rapid germination rate, and other benefits besides food, making it a suitable substitute for fossil products.

The most elementary method of farming seaweed is through the handling of naturally exposed bunches of seaweed. Moreover, in the most progressive approach, the ranchers take an absolute charge of the life cycle of the algae. There are three styles of seaweed cultivation. First is the single rope floating raft (SRFR) method developed by the Central Salt and Marine Chemical Research Institute (CSMCRI). It is suited for culturing seaweeds in an extensive area and greater depth. The second is the fixed bottom long thread method, in which seaweed is made synthetically. And, third is the Integrated Multi-Trophic Aquaculture (IMTA), like polyculture, where two or more organisms are grown synchronically. In IMTA, various marine species from distinct trophic levels are produced unified to promote productivity, reduce wastage, and cater to ecosystem services such as bioremediation^.i

There is enormous potential in India for seaweed cultivation. India is among the 12 mega biodiversity countries globally and has an exclusive economic zone (EEZ) of 2.15 million sq. km. The country's coastline and its diverse water bordering ecosystems sustain the abundant growth of distinct seaweed cultures, with significant commercial value. About 844 seaweed species are recorded from the nation, which has a coastline of 7500 km. On the West Coast, particularly in Gujrat, ample resources are present in the intertidal and subtidal zone. These resources have exceptional potential for the advancement of seaweed-based industries. Tamil Nadu, Gujrat coats, Lakshadweep, Andaman, and the Nicobar Islands are abundant in seaweed. Rich seaweed bed is also found around Mumbai, Ratnagiri, Goa, Karwar, Varkala, Vizhinjam, and Pulicat in Tamil Nadu and Chilka in Orissa. ⁱⁱ

India has 14,500 km of open waterways. Using these inherent assets for seaweed farming can bring many benefits to India. First, seaweed does not need any freshwater, farmable area, or nutritional inputs. As water shortage is rising as a significant challenge in the nation, this is important. Second, seaweed can be collected and utilised to create biofuels whose use is being promoted in India. A change to seaweed-based energy could considerably improve the carbon sequestration potential and reduce the reliance on fossil fuels. Third, prefatory findings of a research study by the University of California show that a small seaweed added to cattle feed can reduce methane discharges from the cattle sector. Since this also exists in the Indian conditions, it will have a noticeable influence in India, and the country has a large cattle population. Fourth, seaweed farming can provide support sites for cultivating fish populations and reversing ocean acidification. This will promote residents' livelihood and income generation along the river, many of whom are also engaged in traditional agriculture.

Supported by the Council of Scientific and Industrial Research (CISR) and CSMRI and their association with the industry, India is advancing towards knowledge-intensive cultivation of seaweeds rather than being dependent on seaweed collection from natural patches. ⁱⁱⁱ

With an investment of about $ 86.8 million, India aspires to expand seaweed production to at least 1 million tons a year by 2025. The investment is part of India’s Pradhan Mantri Matsya Sampada Yojana (PMMSY), Blue Revolution scheme. Passed by the government in May 2020, the scheme will "bring about a Blue Revolution through sustainable and responsible development of fisheries sector in India." ^iv The investment will finance seaweed seed banks, nurseries, tissue culture units, processing, and marketing units, as well as kill training and business cultivation. These investments will also improve the number of environmentally sustainable job opportunities and wages for citizens. By sanctioning 100 per cent FDI through automatic routes in Pisciculture and Aquaculture, the government is also attracting significant investors in this sector.

Start-ups are at the vanguard of an upcoming and promising sector of a global circular economy. The Indian company Sea6 Energy has received a worldwide appreciation for using seaweed to help save the earth. This company is committed to determining the scale and automation of tropical seaweed farming. It generates biomass for fuel and sustainable raw materials for businesses that span agri-foods, wellness supplements, beautifiers, bioplastics, and polymers. It has obtained patents for the entire value chain. It has invented what it calls ''SeaCombine'' – a tractor-like vehicle that scatters seeds and collects tropical sea plants offshore currently in India and Indonesia.^v

Satisfying the circular economy's objectives, the bio-based economy's possibilities look compelling given that it is an innovation-based sustainable system. A vital feedstock for many bio-based goods, seaweed is still at its outset and has the potential to grow exceptionally. Though it has been limited to food uses, its multifaceted use has not been commercially explored. Nevertheless, new seaweed value chains are expected to be ecological and socio-economical gains with the blue revolution scheme.

The article is authored by Karishma Sharma and Bhakti Jain.