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Reading the Timorese Sea

Inside Timor-Leste's First Integrated Ecological Survey

By Blue Ventures

March 4^th, 2026

Timor-Leste, one of the world’s youngest nations, sits on the southeastern edge of the Asia-Pacific. Its seas form part of the Coral Triangle, a global centre for marine biodiversity, famed for its coral reefs and rich marine life. Blue Ventures has worked alongside coastal communities here for more than a decade, supporting marine ecotourism and conservation, and revitalising tenure systems that support small-scale fishers to care for their waters.

Yet caring for the ocean takes more than commitment alone. It calls for action grounded in evidence and data. To better understand the health of Timor-Leste’s waters, our team joined with community members to conduct the country’s first comprehensive and collaborative ecological survey, examining mangrove forests, seagrass meadows, and coral reefs—key ecosystems that quietly sustain fisheries, livelihoods, and food security for many coastal communities.

The team set out in late September and surveyed into October 2025, when the dry season had settled across Timor-Leste. Winds blowing north from Australia swept across the Timor Sea as we made our way toward the starting point, Atáuro Island, preparing to begin the work waiting below the surface.

The excitement grew as more people joined. Fishers, women’s groups, and community members from across the area stepped forward to take part. Representatives from the Ministry of Agriculture, Livestock, Forestry, and Fisheries (MALFF), the Atáuro Administrative Authority, and partners, including the Coral Triangle Center (CTC), also joined the effort.

As the collaboration brought together many who were new to ecological surveys, each day began with careful preparation. Briefings on safety, survey techniques, and first aid became part of our routine, helping the group build confidence before entering the water. These sessions created space for learning and exchange, as experienced researchers worked alongside community members who knew these seas intimately.

Over time, the team moved with growing coordination and trust. By the time we stepped off the boats and descended beneath the surface, what had begun as training had become a shared effort to observe and document the life below.

“This is a completely new experience for me. I feel both curious and excited to take part in the seagrass survey. I never imagined that one day I would be collecting data on seagrass, especially knowing how important it is as a nursery for young fish,” said Juliana Oliveira from Arlo.

The work took us through three Tara Bandu Locally Managed Marine Areas (LMMAs) across Atáuro, including Iliknamu, Pala, and Arlo, before continuing to Ilimano in Manatuto Municipality, where we surveyed the coastal areas of Behedan, Lian-Lidun, and Usu’un. Tara Bandu, a long-standing Timorese tradition, weaves community rules into daily life to guide the use and protection of natural resources. Across these sites, the surveys revealed how communities carefully balance fishing, harvesting, and conservation in the seas that sustain them.

The data we gathered beneath the surface began to tell its own story. Across the seagrass meadows of Atáuro’s LMMAs, the ecosystem was assessed as being in good condition, with an average Seagrass Ecological Quality Index (SEQI) score of 0.73. Seagrass coverage averaged 42.9 percent, with blades reaching up to 19 centimetres, forming underwater fields that shelter young marine life.

Seagrasses are protected under Timor-Leste’s National Ocean Policy and remain essential to the livelihoods of coastal communities. These underwater meadows shelter juvenile fish, crabs, mollusks, and sea urchins, supporting food security in coastal areas where reefs, seagrass beds, and mangroves form a tightly linked ecosystem.

Our work then led us into the mangrove forests of two LMMA sites, Pala and Uma-Caduac, where we assessed the condition of these coastal woodlands. The results placed both sites in the moderate health category, with scores of 55.25 for Pala and 53.07 for Uma-Caduac. Across the muddy channels and tangled roots, the forests were largely dominated by Sonneratia alba, a mangrove species well adapted to high salinity and an important pillar of the ecosystem.

Beyond supporting coastal life, these mangroves also serve as powerful carbon stores. In Pala, the potential carbon held in aboveground biomass reached 114,343 kilograms per 600 square metres, while belowground roots stored another 33,886 kilograms. Uma-Caduac showed a similar level of significance, with 90,985 kilograms of aboveground biomass and 26,746 kilograms of belowground biomass per 300 square metres. The findings highlight how these forests support both ecosystem health and climate stability.

Our surveys continued along the coral reefs of Ilimano in Manatuto, where we assessed reef composition and overall condition using Point Intercept Transects (PIT) and Manta Tow surveys. Along three transects set between seven and ten metres deep, we recorded the benthic cover beneath us, from live hard and soft corals to algae, rubble, and sand.

In total, seven sites were surveyed in Ilimano and nearby Uma-Caduac. The mean hard coral cover across all sites reached 27.48 percent. Coral cover was broadly similar between fishing grounds and Tara Bandu areas, averaging 27.13 percent and 28.33 percent respectively. Fish biomass, however, told a different story.

Across all sites, biomass averaged 935.76 kilograms per hectare. In open fishing areas it reached 821.45 kilograms per hectare, while Tara Bandu areas held far more, averaging 1,333.41 kilograms per hectare. The difference, more than 500 kilograms of fish per hectare, points to the impact of temporary closures under traditional management, allowing fish populations the time and space to grow and reproduce.

“We look forward to sharing the findings with all stakeholders to inform decision-making and strengthen our efforts to protect the ocean and its resources,” said Nelson Amaral, Fisheries Programme Manager, Blue Ventures Timor-Leste.

Supported by the UK Government through the Darwin Initiative and partners, this first collaborative ecological survey lays the groundwork for long-term, community-led conservation in Timor-Leste. Beyond the data, it reveals something deeper: a shared determination to care for the ocean, shaped by the knowledge and stewardship of the communities that depend on it.

Footnotes

Story by Yoga Putra and Ricardo Valente | Photos by Alex Bartlett, Nelson Amaral, Dedy Martins, Emilio de la Rosa, and Ricardo Valente | Blue Ventures, 2026.

This ecological survey was funded by the UK Government through the Darwin Initiative.

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FootNotes

Story by Yoga Putra and Ricardo Valente | Photos by Alex Bartlett, Nelson Amaral, Dedy Martins, Emilio de la Rosa, and Ricardo Valente | Blue Ventures, 2026.

This ecological survey was funded by the UK Government through the Darwin Initiative.

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