Bottom-up blue: Communities are quietly reshaping their relationship with the sea along the East African coast

As the first light of day pricks through the Indian Ocean, Asha Musa wades through shallow water along Tanzania’s coast, her bare feet sinking into the wet sand. She moves methodically, harvesting strands of seaweed from underwater ropes. It’s steady, hands-on work — and for Musa, worth it.

“The ocean gives,” she said, brushing saltwater from her arms. “But only when we learn to give back.”

Along the East African coast and across island nations in the western Indian Ocean, communities are quietly reshaping their relationship with the sea. Away from official blue economy strategies and policy documents, small-scale fishers, seaweed farmers and coastal residents are building local, sustainable ocean-based livelihoods rooted in tradition and ecological awareness.

This is the “true” Blue Economy—hand-built with salt-worn tools, guided by ancestral knowledge, and powered increasingly by women like Musa.

Musa, 38, once harvested seaweed simply to survive. Today, she leads a women-run cooperative in Zanzibar that transforms sun-dried spinosum and cottonii seaweed into organic fertiliser pellets, now sought after by farmers across the region. The shift didn’t come from aid agencies or foreign investors. It began, she said, “with the idea that the sea could feed both the land and our children’s future.”

Her cooperative employs over 40 women, most of them single mothers. The enterprise pays three times the price of raw seaweed sales than middlemen. But the gains aren’t only financial. “Before, we only saw seaweed as a crop,” she said. “Now we see it as a solution—to poor soil, to poverty, to the problem of waste.”

The fertiliser, processed in solar-powered kilns and enriched with fish scraps from local markets, restores depleted farmland while cutting down reliance on imported chemical inputs. The result is a closed-loop, climate-smart model that echoes across a coastline increasingly battered by rising tides and dying reefs.

Meanwhile, some 2,000 kilometres south, in Madagascar’s Mahajamba Bay, a former shark fisher named Tovonay Rakoto steers his dugout canoe through a labyrinth of mangrove roots. For years, Rakoto hunted sharks to feed his family and pay his children’s school fees—until dwindling catches and tighter international restrictions made the trade unsustainable.

Now, at 52, Rakoto farms mud crabs in tide-fed pens nestled among the mangroves. The brackish channels, once hiding grounds for apex predators, now nurture an export delicacy that earns him steady income while giving the ecosystem space to recover.

“These mangroves saved me,” he said. “They brought the crabs, and they brought back the fish, too.”

Crab aquaculture, once viewed as a niche experiment, has gained traction across Madagascar, supported by non-profits and local councils that recognise the dual benefit: economic resilience and environmental restoration. The mangroves—home to shrimp nurseries and sequestering more carbon per hectare than rainforests—are thriving once more.

But Rakoto is wary of outside narratives. “The people who come in helicopters talk about ‘blue economy’ like it’s a new idea,” he chuckled. “But we’ve always known the ocean is our mother. We just had to remember how to take care of her.”

This grassroots momentum comes at a time when the ocean is dominating global agendas. At the recent United Nations Ocean Conference (UNOC3) held in Nice, France, world leaders pledged bold action to accelerate marine conservation and promote sustainable blue economies. Yet beneath the optimistic declarations, deep fault lines emerged. Delegates from small island nations and coastal African states voiced concern that international financing still favours large-scale maritime infrastructure and offshore extraction—leaving little room for indigenous knowledge or smallholder innovation. “The ocean is not just Gross Domestic Product (GDP) beneath the waves,” said Immaculate Semesi, director general of Tanzania’s environmental management council at the conference. “It’s identity, food, medicine, culture. Our people must be partners, not bystanders.” For communities like Asha Musa’s and Tovonay Rakoto’s, this debate isn’t theoretical. It shapes their access to coastlines, capital, and a stake in deciding the ocean’s future.

Bottom-up blue

Across the region, from Lamu’s dhow builders to the Comoros’ sea cucumber farmers, a new pattern has emerged: community-led marine ventures rooted in tradition, driven by necessity, and adapted to today’s ecological realities.

And increasingly, these grassroots models are challenging the conventional notion of the Blue Economy—often defined by large-scale infrastructure, port development, luxury tourism, and offshore oil and gas exploration. While governments tout billion-dollar blue growth strategies, the people closest to the ocean are crafting a quieter, regenerative path.

Amina Khalid, a marine policy researcher at the University of Dar es Salaam, sees this divergence as both tension and opportunity. “What we call ‘small-scale’ is in fact the backbone of coastal economies,” she said. “But they are rarely at the policy table. Instead, blue economy plans are dominated by top-down investments that risk displacing the very communities who’ve stewarded these ecosystems for generations.”

A 2024 report by the Western Indian Ocean Marine Science Association found that while regional blue economy initiatives promise job creation and sustainability, less than 15 per cent of funds go to community-led programmes. “We must ask: who owns the ocean’s future?” said Khalid.

For many local leaders, that question is urgent. In Kenya’s Kilifi County, village residents have protested a proposed deep-sea port project that would destroy mangrove habitats and ancestral fishing grounds. In the Seychelles, small-scale fishers have petitioned for clearer tenure rights amid rising tourism pressure. And in Zanzibar, Mussa’s cooperative faced early resistance from officials more eager to back export-oriented seaweed ventures than local fertiliser trials.

“People think because we are women and poor, we cannot innovate,” Mussa said. “But we are proving otherwise.”

A model worth replicating

What unites these stories is not just a shared geography—but a shared ethos. One where economic development is measured not by GDP but by the health of coral reefs, by full fishing nets and full stomachs, by the dignity of local work and the survival of cultural memory.

These models are also, importantly, low-carbon. Seaweed farming captures carbon. Mangrove restoration does the same—while defending coasts from storm surges. Crab aquaculture emits a fraction of the greenhouse gases compared to industrial fisheries. In an age of climate reckoning, these small-scale practices may offer scalable solutions for coastal resilience.

“There’s wisdom here the world is finally starting to notice,” said Khalid. “Nature-based economies built not on extraction, but reciprocity.”

Yet risks remain. Climate change is accelerating. Sea-level rise is already salting farms in Zanzibar. Coral bleaching events are decimating marine life. And without strong policy safeguards, even promising community ventures can be co-opted by outside investors.

That’s why local leadership is key. In Madagascar, Rokato now trains other former fishers in crab farming, teaching them to construct pens using only native materials. In Zanzibar, Musa’s group is working with regional universities to study soil health improvements and scale their production to neighbouring islands.

And across East Africa, new coalitions are forming—linking fisher cooperatives, women’s groups, and conservationists under a shared banner of ocean justice.

Who gets to decide?

Back in Zanzibar, Musa packs the last sacks of fertiliser for delivery to a mainland farmer cooperative. The wind lifts her hijab as she loads the boat. “We are not waiting for someone to save us,” she said. “We are saving ourselves—with the sea beside us.”

The boat pushes off, leaving behind a trail of ripples that catch the rising sun like scattered pearls. Around her, the ocean is not a frontier to be conquered, nor a resource to be mined. It is a partner. A provider. A place of memory—and future.

As the world rushes to chart blue economies through billion-dollar deals and strategic plans, perhaps it’s time to listen to the people who have always lived by the tides. For them, the question is not what the ocean can do for development. It’s who gets to decide how.