Seaweed Cultivation

Seaweed cultivation in India represents a growing sector with significant potential for economic development, environmental sustainability, and community empowerment. Here’s an overview of seaweed cultivation in India, its benefits, challenges, and prospects.

Seaweed cultivation is an alternative for employment generation of seaweed products as it diversifies marine production and its opportunities for enhancing fish farmer income.

A National Conference on Promotion of Seaweed Cultivation was organized at Koteshwar (Kori Creek), Kutch, Gujarat to implement seaweed cultivation on a Pan India basis and to emphasize the promotion of seaweed cultivation.

The pilot project of Kori Creek can be a game changer for seaweed cultivation in India.

Seaweed

Seaweeds are macroscopic algae growing in marine and shallow coastal waters and on rocky shores.

• Seaweeds are wonder plants of the sea, the new renewable source of food, energy, chemicals, and medicines with manifold nutritional, industrial, biomedical, agriculture, and personal care applications.
• Seaweeds are also termed the ‘Medical Food of the 21st Century’ as they are being used as laxatives, for making pharmaceutical capsules, in the treatment of goiter, and cancer, in bone-replacement therapy, and cardiovascular surgeries.
• The major industrial applications of seaweeds are as a source of agar, agarose, and carrageenan used in laboratories, pharmaceuticals, cosmetics, cardboard, paper, paint, and processed foods.

In India, there are 46 seaweed-based industries, 21 for Agar and 25 for Alginate production, but they are not functioning up to their rated capacity, due to the short- supply of raw materials.

Read: Blue Food

Seaweed cultivation in India

India, with its vast coastline extending over 7,500 kilometers, offers a conducive environment for seaweed cultivation, especially along the coasts of Tamil Nadu, Gujarat, and the Andaman and Nicobar Islands.

• Rich seaweed beds occur around Mumbai, Ratnagiri, Goa, Karwar, Varkala, Vizhinjam, and Pulicat in Tamil Nadu, Andhra Pradesh, and Chilka in Orissa.

Species Cultivated: The commonly cultivated seaweeds in India include species like Kappaphycus alvarezii (red algae) and Sargassum (brown algae), known for their high commercial value.

• Out of the 844 seaweed species, India possesses around 434 species of Red Algae, 194 species of Brown Algae, and 216 species of Green Algae.
• The Red Algae Gelidiella acerosa, Gracilaria edulis, G. crassa, G. foliifera, and G. verrucosa are farmed for manufacturing Agar, and Brown Algae Sargassum spp., Turbinaria spp., and Cystoseira trinodis for the production of alginates and liquid seaweed fertilizer.
• The quantity of seaweed available currently is inadequate to meet the raw material requirement of Indian seaweed industries.
• Seed stock of seaweeds is traditionally collected from the sea bed in shallow waters along the southeastern coast of Tamil Nadu.
• Further, continuous, indiscriminate, and unorganized harvesting has resulted in the depletion of natural resources.
• Seaweed cultivation is a highly remunerative activity involving simple, low-cost, low-maintenance technology with a short grow-out cycle.

Traditional vs. Modern Cultivation: Seaweed cultivation in India has transitioned from traditional methods to more modern, efficient practices. This includes the use of rafts and long-line cultivation techniques, which increase yield and efficiency.

Benefits

• Economic Opportunities: Seaweed farming provides livelihood opportunities for coastal communities, especially for fishermen during lean fishing periods.
• Industry Applications: Seaweed is used in various industries, including pharmaceuticals, food processing, cosmetics, and biofertilizers, contributing to economic diversification.
• Environmental Impact: Seaweed cultivation is environmentally sustainable, requiring no freshwater, land, or fertilizers. It also helps in carbon sequestration and maintaining marine biodiversity.
• Nutritional Security: Seaweeds are a source of essential nutrients, vitamins, and minerals, contributing to food and nutritional security.

Potential climate benefits of seaweed cultivation

Several studies indicate the potential for wild seaweed forests to contribute to ocean carbon sequestration.

• Under an atmospheric CO2 removal and sequestration scenario for seaweed forests, seaweeds absorb dissolved inorganic carbon in surface waters, reducing the partial pressure of aqueous (i.e., dissolved) CO2, and eventually driving the flux of CO2 from the atmosphere into the ocean.
• It was reported that seaweed farms could significantly lower ocean surface dissolved CO2 and greater air-sea CO2 flux (i.e., increased CO2 flux into the ocean) compared to reference areas outside seaweed farms, indicating an atmospheric CO2 sink.

Climate benefits could be realized from seaweed farming through the replacement of fossil fuels with seaweed biofuels.

• While the use of seaweeds for biofuels must be traded off against other potential uses, such as human food, seaweeds are considered a viable option as a third-generation biofuel feedstock given their fast growth rates and lack of need for arable land, freshwater, and fertilizer for growth.
• Moreover, seaweed biofuels are considered less toxic and produce fewer pollutants than fossil fuels.
• Technologies considered feasible for seaweed biofuel production include anaerobic digestion for biogas, ethanol fermentation, and hydrothermal liquefaction for bio-oil, as these methods each allow for the use of wet seaweed biomass, avoiding the energy-intensive seaweed drying process.

Enhancing livestock feeds with small quantities of some seaweed species can reduce the enteric methane emissions from ruminant livestock, providing a potential pathway for climate mitigation.

To summarise, seaweed commercial use pathways have been proposed for carbon sequestration and GHG emissions reduction, with varying levels of progress towards implementation. These pathways include:

• displacing carbon-intensive energy with seaweed biofuels
• reducing livestock methane emissions with seaweed feed
• displacing land-based crops with seaweed foods, providing ocean carbon sequestration through the intentional sinking of seaweeds
• providing land carbon sequestration in seaweed products.

Challenges

• Lack of Awareness: There is a general lack of awareness about the benefits and methods of seaweed cultivation among potential cultivators.
• Technology and Training: Access to modern cultivation technology and training for farmers remains limited.
• Market Linkages: Developing robust market linkages for seaweed products, both domestically and internationally, is essential for the growth of this sector.
• Policy and Regulatory Framework: There is a need for a comprehensive policy framework to promote seaweed cultivation, including subsidies, insurance, and quality standards.

Future Prospects for Seaweed Cultivation

Government Initiatives

The Indian government, recognizing the potential of seaweed farming, has launched various initiatives and schemes to promote this sector.

• The Pradhan Mantri Matsya Sampada Yojana (PMMSY) aims to enhance fish production, including seaweed cultivation.
• The Seaweed Mission for commercial farming of seaweeds and its processing for value addition towards boosting the national economy was launched in 2021 by TIFAC.

Research and Development: Increased investment in R&D for high-yielding varieties and efficient cultivation techniques can significantly boost the industry.

Sustainable Practices: Emphasizing sustainable and eco-friendly cultivation practices will be crucial for long-term growth.

Export Potential: There is considerable potential to expand into international markets, given the global demand for seaweed in various industries.

Read: Blue Revolution

Global seaweed market

With its ability to sink carbon, sustain marine biodiversity, employ women, and unlock value chains, seaweed farming demonstrates how development, climate, and nature work together to generate value and uplift communities.

• Seaweed farming can help build a world free of poverty on a livable planet and has enormous growth potential.
• Farmed seaweeds are an important component of human diets in several Asian countries (FAO 2020).
• Most of the global farmed seaweed production is processed for direct human consumption or hydrocolloids (i.e., carrageenan, alginate, and agar) used as stabilizing, thickening, suspending, and gelling agents in food, cosmetics, and pharmaceuticals.
• While global seaweed production tripled from 2000 to 2018, the growth rate of the industry has slowed since 2015, largely due to a reduction in tropical seaweed production in Southeast Asia, and primarily Indonesia.
• Seaweed farming is an emerging industry in several African countries, including Kenya, Mozambique, and Namibia, with a perceived potential for expansion in these regions.

Conclusion

Seaweed cultivation in India offers a promising avenue for sustainable economic development, especially for coastal communities. By addressing challenges related to technology, market access, and awareness, and leveraging government support and international demand, India can harness the full potential of this sector. With its environmental and socio-economic benefits, seaweed cultivation aligns well with India’s broader goals of sustainable development and blue economy.

-Article by Swathi Satish