By Dr. Chanagun Chitmanat
Southeast Asia, including Thailand, is highly dependent on inland and coastal ecosystems for food, livelihoods, and climate resilience. With growing concerns over marine degradation, climate change, and gender inequality in resource access, there is increasing interest in Nature-based Solutions (NbS) to restore ecosystems while supporting sustainable development. Seaweed aquaculture, long practiced in the region, is now being reimagined not just as a livelihood, but as a strategic tool to achieve multiple social and ecological goals. In 2019, world-wide cultivated seaweed production reached 35.8 million tonnes. It accounted for 97% of the world’s seaweed output and had a global market value of US$ 11.8 billion (Sultana 2023). This article explores the potential of seaweed farming in Thailand and neighboring countries as a form of nature-based practice that contributes to climate mitigation, women’s economic empowerment, and regional food security.
Seaweed in Southeast Asia: Ecological and Economic Value
Southeast Asia is one of the world’s largest producers of tropical seaweed, particularly species like Caulerpa lentillifera, Gracilaria fisheri, Kappaphycus alvarezii, and Eucheuma denticulatum (Basyuni 2024). These seaweeds are used in food, cosmetics, pharmaceuticals, and bio-packaging. Beyond its economic utility, seaweed provides ecosystem services such as nutrient uptake, coastal protection, and carbon sequestration. In Thailand, seaweed cultivation is expanding in the provinces of Phetchaburi, Satun, Krabi, Songkhla, Surat Thani, and Trang, where it is often integrated into polyculture systems with fish or bivalves.
Seaweed Aquaculture as a Nature-Based Practice
Seaweed farming embodies several NbS principles: it restores degraded ecosystems, supports biodiversity, and generates sustainable livelihoods. In Thailand and neighboring countries, Integrated Multi-Trophic Aquaculture (IMTA) systems are gaining traction. In these systems, seaweed is co-cultured with shrimp, fish, or shellfish to absorb excess nutrients and reduce environmental impacts. Unlike intensive monocultures, these systems mimic natural processes and enhance coastal resilience.
Case studies from the Philippines and Indonesia demonstrate that seaweed cultivation can reduce the pressure on overexploited fish stocks while offering income alternatives. In Thailand, pilot projects linking seaweed farms to blue carbon markets are underway, indicating the potential to apply NbS to both climate and development goals.
Women in Seaweed Value Chains
Women play a vital but often underrecognized role in seaweed aquaculture. For most low-income and developing countries, the development of seaweed farming has been regarded as a powerful strategy to empower coastal women (Sultana 2023). In several Asian nations such as India, Indonesia, Malaysia, the Philippines, and Sri Lanka, women living in coastal areas participate in seaweed cultivation including drying, processing, and selling as a means of generating income and supporting their households’ finances (Sultana 2023). In Indonesia, women’s participation in seaweed farming led to increased job satisfaction and greater social acknowledgement, outcomes that were similarly noted in both Malaysia and the Philippines (Msuya 2017). In Thailand, although women participate in seaweed farming, they frequently face barriers to owning production assets, accessing credit, or participating in decision-making.
Empowering women in seaweed value chains can have the transformative effects of improving household nutrition, diversifying income, and strengthening community adaptation to climate change. Integrating gender-responsive strategies into seaweed aquaculture programs will ensure more equitable and effective outcomes. For instance, one such strategy could be the provision of training in cultivation practices, information about land rights, and assistance with the creation of cooperatives.
Seaweed and Food Security
Seaweed contributes to food security in multiple ways. As a direct food source, it offers essential micronutrients, iodine, and dietary fiber. Indirectly, seaweed supports the sustainability of aquaculture systems by improving water quality and reducing disease risks. In coastal communities of Thailand and Myanmar, seaweed is increasingly being incorporated into local diets and school feeding programs, promoting healthy nutrition and food sovereignty.
Furthermore, seaweed’s role in climate mitigation, through carbon absorption, helps protect the long-term productivity of coastal ecosystems critical to food production. According to Hossain (2021), commercial seaweed harvesting contributes to the sequestration of approximately 1.5 million tons of carbon each year, representing about 3.2% of the carbon entering the oceans from greenhouse gas emissions. Globally, seaweed farming plays a crucial role in atmospheric CO₂ removal, absorbing an estimated 1.5 petagrams of carbon annually (Krause-Jensen 2016). As such, seaweeds are key contributors to carbon capture in marine vegetated ecosystems (Duarte 1996).
Challenges and Opportunities in Southeast Asia
Seaweed aquaculture in Southeast Asia holds great potential, yet it also encounters a range of challenges that could hinder its sustainable development. One major concern is the sector’s vulnerability to climate-related impacts, such as rising sea temperatures and increasingly frequent storms, which can disrupt production. In addition, the industry faces market instability, largely due to its reliance on a limited range of export products. Additionally, cultivating seaweed in polluted waters can lead to the absorption of harmful substances, especially heavy metals. Certain seaweed species have been found to accumulate these toxins (Giusti 2001), which may pose serious health risks to humans if consumed. Another significant barrier is the lack of comprehensive policies that formally recognize seaweed farming as a Nature-based Solution (NbS), which limits its integration into broader environmental and development strategies.
Moreover, gender disparities persist, particularly in terms of equitable access to resources and opportunities within the sector. Despite these obstacles, addressing these issues can unlock substantial opportunities for inclusive and climate-resilient growth in the region. Indeed, there are opportunities to integrate seaweed aquaculture into national adaptation strategies, coastal zone management, and international carbon financing mechanisms. Regional cooperation through ASEAN platforms could harmonize standards and strengthen knowledge exchanges.
Policy and Programmatic Recommendations
To fully harness the potential of seaweed aquaculture, several policy and programmatic actions are recommended for Thailand and the broader Southeast Asian region. First, integrating seaweed farming into national strategies for Nature-based Solutions (NbS) and climate resilience would strengthen its role in sustainable development. Promoting gender equity is also essential; this includes enhancing women’s participation across the seaweed value chain by providing training, improving access to financial resources, and encouraging leadership opportunities. Additionally, the creation of sustainable market incentives for domestically produced seaweed, along with the exploration of blue carbon credit mechanisms, could boost economic viability. Lastly, fostering inclusive, participatory governance in the management of coastal resources, especially by engaging women and indigenous groups, will help ensure long-term social and environmental benefits.
Conclusion
Seaweed aquaculture, when designed as a Nature-based Solution, has the potential to simultaneously restore marine ecosystems, empower coastal women, and enhance regional food security. Thailand and Southeast Asia are uniquely positioned to lead this transformation. Moving forward, inclusive and integrated policies are essential to realize the full potential of seaweed as a green, blue, and just solution.
AQUADAPT 