How Seaweed Farming Empowers Women and Supports Climate Action Along Tanzania’s Swahili Coast
Authors: Gerald Sumari & Moses Kulaba, Governance and Economic Policy Centre
Featured Photo Credit: Loshni Rodhia, Reef Resilience Network
Climate change has severely affected coastal livelihoods through declining fish stocks, ecosystem degradation, and rising ocean temperatures, disproportionately impacting women in fishing communities. Seaweed farming has emerged as an alternative livelihood that provides income stability, enhances gender equity, and delivers ecosystem services such as carbon capture, shoreline protection, and reduced ocean acidification.
- Introduction
Global climate change has become one of the most pressing challenges facing coastal communities worldwide, particularly in developing countries where livelihoods are intricately tied to fragile marine ecosystems. Rising sea surface temperatures, ocean acidification, and the destruction of nearshore habitats have significantly affected fisheries productivity and the socioeconomic stability of communities dependent on marine resources (IPCC, 2019). In Tanzania, the Swahili coastline, stretching over 1,424 kilometers and encompassing key regions such as Tanga, Bagamoyo, Lindi, Mtwara, and the Zanzibar Archipelago, is increasingly vulnerable to these climate-related disruptions (FAO, 2020). Fishing communities, long the backbone of coastal economies, face declining fish stocks, irregular seasonal patterns, and ecosystem degradation. These changes have disproportionately impacted women, who are often relegated to secondary roles in fisheries yet bear the primary responsibility for household sustenance and income diversification.
Seaweed farming has emerged as a promising alternative livelihood strategy for coastal women in Tanzania. Beyond providing a supplementary source of income, it has grown into a significant economic activity in Zanzibar, where it ranks as the third largest source of income and accounts for approximately 90 percent of marine exports (Msuya, 2013). This growth highlights the potential of seaweed farming not only as a means of economic empowerment for women but also as an important contributor to climate change mitigation and adaptation. From a climate perspective, seaweed aquaculture contributes to carbon sequestration by absorbing atmospheric carbon dioxide and storing it in biomass and sediments, while also providing ecosystem services such as shoreline protection and reduced ocean acidification (Krause-Jensen & Duarte, 2016).
Despite this potential, seaweed farming in Tanzania has not yet been fully recognized or developed as a sustainable economic sector. Current efforts remain fragmented, largely driven by donor agencies and philanthropic initiatives, with limited strategic integration into national marine and climate change policies. Furthermore, women farmers face barriers such as weak institutional support, limited technical knowledge, and restricted access to markets and finance, which constrain their ability to scale production and maximize climate and economic benefits
This study therefore seeks to explore the nexus between seaweed farming, women’s economic empowerment, and carbon sequestration along Tanzania’s Swahili coast. Specifically, it examines the economic opportunities created for coastal women through seaweed aquaculture, the climate benefits associated with carbon sequestration, and the institutional and policy gaps that hinder the sector’s growth. By situating seaweed farming within both the blue economy and climate resilience frameworks, the study aims to provide evidence-based insights and recommendations for scaling up this sector as a transformative pathway for women’s empowerment and climate change adaptation in Tanzania.
- Seaweed Farming and Carbon Sequestration
Seaweed farming refers to the cultivation of marine macroalgae in shallow coastal waters, often using ropes, stakes, or rafts to facilitate growth. Unlike wild harvesting, which can contribute to the depletion of natural stocks, seaweed aquaculture provides a sustainable means of production with both economic and ecological benefits. Globally, seaweed farming has grown into a multi-billion-dollar industry, producing over 35 million tonnes annually and supplying raw materials to food, pharmaceutical, cosmetic, and biofuel industries (FAO, 2022).
From an environmental perspective, seaweed farming is increasingly recognized as an important contributor to the blue carbon framework. Seaweeds, through photosynthesis, absorb carbon dioxide from the atmosphere and the ocean, converting it into biomass. A portion of this captured carbon is sequestered through long-term storage in sediments or through export to deep ocean waters. Krause-Jensen and Duarte (2016) estimate that seaweed ecosystems contribute substantially to global carbon sequestration, with macroalgal forests and farms acting as carbon sinks. Although the exact sequestration potential varies by species and location, emerging evidence suggests that large-scale cultivation could significantly offset greenhouse gas emissions.
Beyond carbon sequestration, seaweed farming provides adaptation benefits to coastal ecosystems and communities. Seaweed farms reduce wave energy, thereby protecting shorelines from erosion. They also elevate local water pH, mitigating ocean acidification, and enhance oxygen levels, which support biodiversity and reduce the risk of hypoxic conditions. These ecosystem services make seaweed farming a nature-based solution that addresses both mitigation and adaptation to climate change.
In Tanzania, seaweed farming particularly in Zanzibar and Pemba has demonstrated the dual benefits of ecological sustainability and socioeconomic empowerment. However, despite its potential to contribute to the country’s Nationally Determined Contributions (NDCs) under the Paris Agreement, seaweed aquaculture has yet to be fully integrated into climate policy frameworks. With improved recognition, investment, and research into carbon accounting methodologies, seaweed farming could position Tanzania as a regional leader in blue carbon and sustainable aquaculture practices.
- Nexus between Climate Change, Seaweed Farming and Carbon Sequestration
The nexus between climate change, seaweed farming, and carbon sequestration represents a crucial intersection of environmental sustainability, economic resilience, and gender empowerment. Climate change has exacerbated challenges faced by coastal communities in Tanzania, including declining fish stocks, saltwater intrusion, and increased vulnerability to storms and coastal erosion (IPCC, 2019). These pressures have heightened the economic and social vulnerabilities of women, who are often responsible for household livelihoods yet face restricted access to productive resources.
Seaweed farming provides an important adaptation pathway, enabling women to diversify income sources away from fisheries and reduce their dependency on diminishing fish stocks. By engaging in seaweed aquaculture, women are not only able to supplement household incomes but also enhance food security, education, and health outcomes within their communities (Msuya, 2013). This diversification strengthens household resilience to climate shocks, while also enhancing women’s agency in economic decision-making.
At the same time, seaweed farming contributes directly to climate change mitigation through carbon sequestration. Seaweeds absorb substantial amounts of carbon dioxide, which can be stored in their biomass or transferred to deep ocean sinks when fragments are detached and transported offshore (Krause-Jensen & Duarte, 2016). In this way, seaweed farms act as localized carbon sinks that help offset greenhouse gas emissions. In addition, seaweed aquaculture improves the ecological health of coastal zones by buffering wave energy, providing habitat for marine species, and maintaining ecosystem functions that are essential for coastal biodiversity.
Therefore, the nexus illustrates a dual dividend: while women benefit from improved economic opportunities and empowerment, communities and ecosystems benefit from enhanced carbon storage and climate adaptation services. Scaling up seaweed farming along the Swahili coast can thus create synergistic gains that address both social equity and environmental sustainability, aligning with Tanzania’s commitments to the Sustainable Development Goals (SDGs), particularly SDG 5 (Gender Equality), SDG 13 (Climate Action), and SDG 14 (Life Below Water).
- Seaweed Farming and Economic Empowerment Opportunities for Coastal Women
Seaweed farming has emerged as one of the most significant livelihood opportunities for women along Tanzania’s Swahili coast. Traditionally marginalized within the fisheries sector, women have increasingly turned to seaweed aquaculture as an alternative that offers greater autonomy, income stability, and social recognition. In Zanzibar, where the practice is most developed, women constitute the majority of seaweed farmers and contribute substantially to household incomes (Msuya, 2013).
Economically, seaweed farming provides a relatively low-cost entry point for women, requiring limited capital investment and basic technical knowledge. Once established, seaweed farms generate steady income through the sale of dried seaweed to domestic and international markets. Current estimates suggest that women farmers in Zanzibar can earn between USD 70 and USD 100 per month, depending on yields and market prices (FAO, 2020). While this income is modest, it represents a critical supplement in communities where alternative employment opportunities are scarce.
Beyond income generation, seaweed farming has broader implications for women’s empowerment. Earnings from seaweed sales enable women to invest in children’s education, improve household food security, and access healthcare services. In some communities, women seaweed farmers have reported greater decision-making power within households and community organizations, marking a shift in gender dynamics traditionally dominated by men (Lugomela et al., 2021). Seaweed farming has therefore become a pathway not only for economic resilience but also for advancing gender equity along Tanzania’s coastline.
In addition, the growing global demand for seaweed-derived products including cosmetics, pharmaceuticals, and biofuels offers significant potential for value addition. With adequate support in processing, branding, and marketing, Tanzanian women farmers could capture higher value from their produce, moving beyond raw material exports into niche international markets. Such a transition would further enhance women’s economic empowerment and position seaweed farming as a competitive sector within Tanzania’s blue economy framework.
Nevertheless, challenges remain. Price volatility in international markets, limited bargaining power, and the absence of cooperative structures reduce women’s profitability. Furthermore, inadequate access to credit and modern farming technologies constrains productivity. These challenges highlight the need for targeted policy interventions and institutional support to strengthen the role of seaweed farming as a driver of women’s empowerment and sustainable coastal development.
- Policy and Practice Gaps
Despite its economic and ecological potential, seaweed farming along Tanzania’s Swahili coast faces significant policy and practice gaps that limit its growth as a sustainable sector. These challenges can be broadly categorized into institutional, technical, financial, and environmental dimensions.
Institutional Gaps: Seaweed farming remains weakly integrated into Tanzania’s broader marine and aquaculture policies. While Zanzibar has made notable progress, the lack of a comprehensive national seaweed strategy undermines efforts to scale the sector. Policy implementation is fragmented, with limited coordination between government agencies, research institutions, and development partners.
Technical Gaps: Women farmers often rely on traditional, low-yield methods and face limited access to improved farming technologies and resilient seed varieties. Rising sea surface temperatures and ocean warming have also affected yields by weakening the productivity of commonly farmed strains such as Eucheuma spinosum and Kappaphycus alvarezii. Without investment in research and innovation, farmers remain vulnerable to climate-induced declines in production.
Financial Gaps: Access to finance remains a major barrier for women farmers, who often lack collateral and financial literacy to secure loans from formal institutions. The sector’s dependence on donor-funded projects has created uncertainty, with few sustainable financing mechanisms available to expand farm acreage, adopt new technologies, or invest in value addition. Limited access to cooperative structures and collective bargaining further weakens women’s market position.
Environmental Gaps: Competition for coastal space with tourism and fishing industries, coupled with environmental degradation, reduces the availability of suitable farming areas. Climate change continues to exacerbate these challenges through rising ocean temperatures, shifting tidal patterns, and increased frequency of extreme weather events, all of which impact seaweed yields and farm stability.
Comparative evidence from Kenya and Madagascar suggests that stronger policy frameworks, investment in seaweed breeding programs, and development of women-led cooperatives can significantly enhance sector resilience. Without similar reforms in Tanzania, however, seaweed farming will remain underdeveloped, leaving coastal women unable to fully harness its economic and climate-related benefits.
- Recommendations
To unlock the full potential of seaweed farming for women’s economic empowerment and climate resilience along Tanzania’s Swahili coast, a set of targeted recommendations is necessary. These measures should address institutional, technical, financial, and environmental barriers while aligning with national development priorities and global sustainability goals.
1. Training and Capacity Building: Strengthen technical training for women farmers on modern aquaculture techniques, resilient seed varieties, and farm management practices. Capacity-building programs should also include business management, marketing, and financial literacy to improve income stability and bargaining power.
2. Policy Reform and Institutional Support: Develop a comprehensive National Seaweed Farming Strategy that positions the sector within Tanzania’s Blue Economy framework. Policy reforms should enhance coordination among government agencies, research institutions, private sector actors, and women’s organizations to create an enabling environment for sector growth.
3. Scaling Up Production and Value Addition: Encourage expansion of farm acreage while supporting investments in processing, packaging, and value addition for products such as cosmetics, pharmaceuticals, and biofuels. This would enable women to capture greater value beyond raw exports.
4. Financing and Investment Mechanisms: Establish tailored financial products, such as microcredit schemes and women’s cooperative funds, to address the sector’s financing gaps. Access to climate finance and blue carbon credits should also be explored to compensate women for the carbon sequestration benefits of seaweed farming.
5. Research and Development: Invest in research on climate-resilient seaweed species, disease management, and carbon accounting methodologies. Partnerships with universities, international research institutes, and regional organizations should be promoted to build a stronger knowledge base.
6. Environmental Management and Coastal Zoning: Introduce integrated coastal management practices that balance seaweed farming with tourism, fisheries, and conservation needs. Clear zoning and environmental monitoring frameworks would minimize conflicts and protect marine ecosystems.
- Strengthen Women seaweed farmers Association, as vehicles for engaging with government policy makers and other stakeholders while protecting the interests of women sea weed farmers. The existing networks are still infant, suffer from nascent resources and internal capacity challenges to into large scale ventures. Moreover, women sea farmers face significant health risks due to poor protection gear and over exposure to salty ocean water. Women complain of skin rushes and other risks due to over exposure.
By implementing these recommendations, Tanzania can transform seaweed farming into a resilient and competitive sector that delivers triple dividends: economic empowerment for women, enhanced climate mitigation through carbon sequestration, and strengthened adaptation for coastal communities. Aligning these efforts with the Sustainable Development Goals—particularly SDG 5 (Gender Equality), SDG 13 (Climate Action), and SDG 14 (Life Below Water)—would further position Tanzania as a leader in inclusive and sustainable blue economy development.
- Conclusion
Seaweed farming holds transformative potential for Tanzania’s Swahili coastline, offering a sustainable livelihood for women, a pathway for climate change mitigation, and a contribution to the country’s broader blue economy agenda. As climate change continues to undermine traditional fisheries and coastal ecosystems, seaweed aquaculture provides an alternative that empowers women economically while also delivering critical ecological services such as carbon sequestration, shoreline protection, and improved marine biodiversity.
The evidence presented in this study demonstrates that while seaweed farming already plays a significant role in Zanzibar’s economy accounting for nearly 90 percent of marine exports it remains underdeveloped along the broader Tanzanian coastline. Institutional, technical, financial, and environmental gaps continue to constrain its full potential. Women farmers face challenges such as weak policy support, limited access to technology and finance, and exposure to climate-induced risks. Addressing these barriers is essential if seaweed farming is to deliver its dual dividends of economic empowerment and climate resilience.
Targeted interventions, including stronger policy frameworks, enhanced training, value addition, and innovative financing models, can unlock the sector’s potential. By scaling up seaweed farming and integrating it into national climate and marine strategies, Tanzania can position itself as a leader in sustainable aquaculture and blue carbon initiatives in East Africa.
In conclusion, seaweed farming is more than an economic activity; it is a climate-smart development strategy that empowers women, supports households, and strengthens ecological resilience. Harnessing this potential requires a coordinated effort among government, development partners, research institutions, and coastal communities. If pursued strategically, seaweed farming can significantly contribute to Tanzania’s achievement of the Sustainable Development Goals, while building a resilient and inclusive coastal economy.
References
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Krause-Jensen, D., & Duarte, C. M. (2016). Substantial role of macroalgae in marine carbon sequestration. Nature Geoscience, 9(10), 737–742.
Lugomela, C., Msuya, F. E., & Kyewalyanga, M. S. (2021). Seaweed farming and gender dynamics in coastal Tanzania. Journal of Applied Phycology, 33, 1457–1468.
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