Maddy Bolt, Nusa Penida, Indonesia – Storm clouds loom overhead as Nyoman Mitri peers out at rows of seaweed lines stretching across the shallow tidal waters of Nusa Penida. Her weathered hands move with practiced ease as she secures a strand of green seaweed to a rope.

"It never used to be like this," she says. "It's only been the last 10 years or so that rain has begun to seriously damage the seaweed."

Ibu Mitri, or Mrs. Mitri, as she's known by her community, is sharing her seaweed cultivation techniques with a few tourists. Together, they sort through fresh seaweed, discarding damaged strands and carefully tying healthy green ones onto lengths of rope, preparing them to be returned to the sea and fastened to wooden posts, where they'll continue growing until the next harvest.

As she ties hundreds of strands of seaweed back onto the lines, lulled into a methodical rhythm, she begins to share her concerns: the changing climate, increasing development, and the growing unreliability of each harvest. With a shy smile, she speaks of how increased rainfall and more frequent storms have threatened traditions once guided by the seasons, not by storms.

Nestled between the rocky shores of Lombok and the popular vacation destination of Bali lie two sleepy islands: Nusa Penida and Nusa Lembongan, best known for their vibrant wildlife, scuba diving spots, and surf breaks.

While the underwater world teems with life, Nusa Penida and Nusa Lembongan also nurture a vibrant community above the surface. Along the shores of both islands, seaweed-harvesting communities have flourished for hundreds of years. For generations this work has been the domain of women, passed from mother to daughter. Their traditions have endured colonization, the COVID-19 pandemic and rapid development.

However, the looming threat of climate change hangs steadily over the islands like a stagnant storm cloud, always on the periphery and in the backs of everyone's minds. Encroaching slowly, but steadily, rendering these feminized knowledge systems at dire risk of disappearing.

"More frequent storms and unpredictable rainfall patterns are disrupting our practices," Ibu Mitri says. "When there is more rain, a larger portion of the crop dies, and we have to remove the damaged seaweed from the lines more quickly and more often."

Women like Ibu Mitri now stand at a crossroads between preserving ancient traditions and adapting to a rapidly transforming world.

Indonesia is one of the biggest seaweed producers in the world, exporting both raw and processed seaweed products. In 2021 alone, Indonesia produced an estimated 9 million metric tons of seaweed valued at more than $1 billion, making the country the seventh-largest exporter of agar and sixth-largest exporter of carrageenan globally. These components, derived from seaweed, are widely used as stabilizers, thickeners and gelling agents in food, cosmetics and pharmaceuticals.

On Nusa Penida, the most commonly harvested species of seaweed is Kappaphycus alvarezii (formerly Eucheuma cottonii), known locally as grandong or katoni. It's a red alga that thrives in shallow, clear saltwater throughout Southeast Asia. This species is exported in large quantities to the Japanese, Chinese and U.S. markets due to its rich carrageenan content.

Ibu Mitri also speaks of a concerning virus wiping out seaweed in recent years: "The virus never used to be here, now we see it killing a lot more of our seaweed, more often." She's also observed a troubling pattern: "There seems to be more seaweeds dying off from the virus during heavier rains."

All seaweed species have an optimal temperature, pH and salinity range. Storms bring large influxes of freshwater, altering the pH and salinity of the local marine environment. For seaweed, this leads to stress, higher vulnerability to disease and viruses, and ultimately death.

In addition, tourism development often means clearing mangroves to build hotels and villas. This removes natural erosion protection and increases runoff, making seaweed growth even more vulnerable to drastic precipitation changes. On Nusa Penida, ongoing construction is making it increasingly difficult for locals to access harvesting sites, as flooding and altered coastal infrastructure reshape the shoreline.

During COVID-19, many women returned to seaweed cultivation as tourism collapsed in the area. Their harvests helped provide for families during a time of deep economic uncertainty. Seeing how important seaweed cultivation was during this period of unrest and turmoil, Ibu Mitri and her family say they feel more steadfast in the importance of continuing their seaweed traditions through other challenges.

Now, as tourism steadily returns, some women have shifted back toward hospitality jobs; however, a large portion of women remain in their roles as seaweed harvesters.

"It's because we can bring our children with us to work," says a woman from Nusa Lembongan. "The cost to start is low, the schedule is flexible, and we can pass our knowledge directly to our children while we harvest, helping us stay efficient, care for them, and teach them skills they can one day use to earn a living."

However, the region is not immune to the impacts of unchecked tourism, and maintaining tradition amid climate change and development pressures remains a challenge. Yet many local women have risen to the challenge.

Ibu Mitri partners with a local tour operator, Ecotourism Penida, to bring tourists to interact with the knowledge holders of the area, offering them a chance to learn more about local cultivation techniques. Ibu Mitri isn't the only local woman who has recognized an opportunity in sharing her traditions with others.

On neighboring Nusa Lembongan, two women work methodically, chatting, giggling and tying strands of seaweed to ropes. When asked whether many visitors have shown an interest in their work, they chuckle, laugh and point out another tourist walking by: "Many tourists come down now to take photographs of us harvesting seaweed!" Recognizing this interest, these women also began charging tourists for photographs and explanations about their traditions.

Back on Nusa Penida, many seaweed farmers have also worked with NGOs to share their knowledge in support of island-wide conservation and coral reef restoration efforts. Anchor damage from fishing, dive and snorkel boats; tourism rafts shading and physically damaging corals; and the dragging of fishing nets and traps across reef flats have all contributed to the decline of coral beds across Nusa Penida and Nusa Lembongan. In the past, before NGOs and local communities worked hand in hand, coral beds were actually removed to make room for seaweed farming.

Recognizing the decline in healthy coral cover in the area, biologist Andrew Taylor began a restoration project in 2018 targeting degraded reef zones in northern Nusa Penida, which had shown no natural recovery after seven years of monitoring. Taylor, in partnership with his organization Blue Corner Marine Research and Komunitas Penyelam Lembongan, a local divers' group, initiated a four-phase plan that included a pilot project and continued community involvement.

Seaweed harvesters on Nusa Penida shared their planting techniques with coral restoration teams across the island. These methods were adapted for coral restoration, in a collaboration that helped develop techniques for transplanting coral species onto coated metal frames and mesh designed to withstand the area's strong currents.

Marine park zoning has since reduced destructive activities in important coral reef habitat, and together with the divers' group, local NGOs and seaweed farmers, collaborative educational workshops have been held to establish best practices and codes of conduct for coral reef habitat care and rehabilitation.

As climate change continues to shape the world around us, demand for seaweed, as a biofuel and a sustainable alternative for fertilizers, plastics and even food systems, will continue to grow. From Lombok east to Sumba, many seaweed farming and processing operations are scaling up production, and increasing income and job stability for women in particular. Seaweed production in Indonesia is still driven almost entirely by community-based farming, with women now leading 40% of Indonesian seaweed start-ups. This connection was highlighted by David Jose Vivas Eugui, section chief for trade, environment, climate change and sustainable development at the United Nations Conference on Trade and Development (UNCTAD), when he described seaweed as "an area where women are taking the lead."

Indonesian women are thus at an inflection point where they can capitalize on their experience to contribute to long-term environmental solutions, while continuing to honor their intergenerational knowledge.

The storm clouds looming over the islands of Nusa Penida and Nusa Lembongan are more than just a passing weather system; they signify the larger changes taking place across this archipelago. Amid this uncertainty, however, women continue to adapt, remaining on the shore, tying the next generation to the sea. They continue to pass knowledge from mother to daughter, partner with NGOs, and share their wisdom with curious tourists. Rooted in the strength of their traditions, they carry on, having weathered change and uncertainty before.

Maddy Bolt is a scientist, writer, photographer and founder of the nonprofit OceanFolx. Based in Indonesia, she works in partnership with local women to teach swimming, surfing and ocean safety, while documenting environmental stories across the archipelago and beyond.

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Source: https://news.mongabay.com/2025/06/indonesian-women-sustain-seaweed-traditions-in-a-changing-climate