Habitat with history
Fieldwork described two major seagrass areas around Moso in 1988, including a broad reef-sheltered eastern lagoon.
North-west Efate Vanuatu
Dugongs of Havannah Harbour and Moso Island
A definitive local guide to the habitat, seagrass, research and community knowledge behind one of Vanuatu's most intriguing dugong landscapes.
Illustrative hero image; it is not used as evidence of two animals together at Moso or in Havannah Harbour.
The short answer
Are there dugongs in Havannah Harbour?
Yes. Historical aerial observations, community knowledge and a modern drone survey show that dugongs use the wider Moso–Havannah–Lelepa system. What nobody can yet say is how many animals use it, whether the same individuals stay year-round, or how often a visitor might see one.
That makes Havannah Harbour scientifically interesting for the right reason: it is not a single “dugong spot”. It is a connected seascape where shallow, sunlit margins sit beside deep sheltered water and passages link Moso, Lelepa, Efate and habitat farther east.
Recent 2026 reports from people working around Moso and Havannah Harbour describe repeated sightings. They make an encounter a genuine possibility, but until search effort and no-sighting days are recorded consistently, they cannot establish a daily pattern or visitor success rate.
For the country-wide picture, compare Havannah Harbour with Epi, Malekula, Santo and other Vanuatu dugong areas.
Modern confirmation
A 2021 VESS drone survey photographed at least one live dugong inside its Havannah Harbour survey block.
The crucial unknowns
Population, residency, seasonality, current meadow boundaries and encounter probability remain unmeasured.
Read the harbour as a system
One harbour, several connected habitats
The ecological story is the relationship between food, shelter, depth and movement—not a pin on a map.
Shallow seagrass margins
Dugongs are marine herbivores. The shallow edges of Moso, Lelepa and Efate provide the light and sediment seagrass needs, placing potential food around several shores rather than at one fixed site.
Protection from open weather
Efate, Moso, Lelepa and their reefs reduce exposure to prevailing south-easterly weather. Shelter is relative—not permanent—but it gives an animal choices when one shore is windier than another.
Feeding shallows beside deep water
The harbour's central basin commonly exceeds 100 metres, while narrow illuminated margins remain close by. Deeper water may provide travel or refuge beside feeding habitat, although this has not been tested with tagged dugongs.
Passages between useful patches
Channels and reef edges connect Moso, Lelepa, Efate, Undine Bay and habitat farther east. A dugong could potentially move between useful patches as tide, food, weather or disturbance changes, although no animal has been tracked through this local system.
The habitat beneath the story
Seagrass is why the harbour matters
Seagrass is not seaweed. It is a rooted marine flowering plant, and it is the foundation of dugong life: food, nursery habitat for fish, clearer water, sediment stability and coastal protection.
The most detailed Moso baseline comes from botanical fieldwork in 1988. Researchers described two major areas:
- Moso's south-west shore: dense intertidal seagrass on coarse or gravelly sand, with cover in the survey's highest category—greater than 75%.
- Moso's eastern lagoon: a reef-sheltered meadow with five species, a dense inshore band about 30 metres wide and sparse Halophila ovalis extending at least 200 metres offshore.
Moso was included in 2017–2018 monitoring, which reported generally better condition and diversity at the monitored north-Efate beds than at more urbanised southern-Efate sites. But historical richness is not a current map. Cyclones, sediment, water quality, anchoring, propellers and changing light can move or fragment a meadow. The next essential project is to map today's cover, species and grazing signs in the water.
Existing research
What has actually been studied?
1987–1989
Questionnaires and aerial reconnaissance
Vanuatu's first national investigation linked local reports with roughly 1,000 kilometres of aerial reconnaissance. Observers recorded an adult between Moso and mainland Efate and an adult with a young animal between Lelepa and Efate. The enduring result was spatial: the wider harbour, Undine Bay and reefs east toward Kakula may operate as connected habitat.
1988–1990
National seagrass field survey
Researchers described the two major Moso seagrass areas summarised above. It remains the best site-specific botanical baseline, but it is a historical snapshot rather than proof of today's meadow boundaries.
2016–2018
Community knowledge and Efate monitoring
A national interview programme gathered remembered sightings, fishing overlap and local priorities across Vanuatu. Separate seagrass monitoring included Moso and found generally better-condition beds toward north Efate. The first work located questions; the second measured habitat at selected stations.
2021–2022
The Havannah Harbour drone survey
VESS flew programmed transects over a deliberately selected Havannah Harbour block and a separate Pele–Kakula–Emua block. Images in one Havannah cell showed travelling dugong detections across adjacent transects. The researchers could not tell whether one animal had been photographed repeatedly or several animals were present; the adopted protocol treated the image sequence as two detections for analysis, although these were not two photo-identified individuals.
The defensible conclusion: at least one live dugong was photographed inside Havannah Harbour during the survey. The third protocol detection was in the separate Pele–Kakula–Emua block and must not be presented as a Havannah or Moso feeding record.
Now
Turn observations into comparable evidence
Local sightings and original footage are valuable when the date, broad area, search effort, conditions, behaviour and no-sighting days are recorded. That is the path from an exciting local story to a measured encounter pattern.
Evidence without exaggeration
What we know—and what remains open
Supported by the evidence
- Dugongs have used the wider Moso–Havannah–Lelepa system at different times over several decades.
- Moso supported dense, extensive seagrass at the surveyed sites in 1988.
- At least one live dugong was photographed in the Havannah Harbour survey block in 2021.
- Food, relative shelter, depth variety and connectivity provide a strong habitat explanation.
- Local knowledge has repeatedly helped researchers choose where to investigate.
Not yet established
- How many individual dugongs use Havannah Harbour or Moso Island.
- Whether the same animals are resident or simply return episodically.
- A scientifically demonstrated season or visitor encounter rate.
- Whether the deep basin is used specifically for resting or refuge.
- The complete present-day extent, condition and cyclone recovery of local seagrass.
Local knowledge
Indispensable, specific—and different from a census
People who work these waters notice where animals surface, where seagrass changes and when boats, nets or weather alter a familiar pattern. That knowledge has repeatedly pointed researchers toward places worth surveying.
Recent local reports are encouraging because they show where structured observation should begin. Their value rises sharply when every search is logged, including the days when no dugong is seen.
Its strength is context. Its limitation is identity and effort: the same animal can be reported many times, several animals can be remembered as one group, and a quiet week may reflect poor visibility or fewer observers rather than absence.
Local knowledge tells us where to look. A structured field log tells us what the pattern may mean.
Exact feeding locations, mother–calf sites and private GPS pins should remain with customary owners, researchers and relevant authorities—not become public chase points.
Original footage
Watch the real Moso Island setting
Reading a wild sighting
The first clue may be only a breath
Dugongs are large, but they surface quietly, lack a dorsal fin and can change direction below the surface.
A rounded muzzle
Often the first visible moment is a nostril-bearing muzzle, a short curve of back and a tail disappearing with little splash.
A pale sediment plume
Head-down grazing can disturb fine sediment. A plume can suggest feeding, but its cause and the animal's location must be observed—not assumed.
Cropped feeding trails
Paired or winding tracks through a meadow can reveal grazing use. They should be recorded with scale and habitat data, not followed as a route to an animal.
A calf changes everything
An adult with a smaller animal requires more space and less pressure. Never position a person or vessel between them, the surface or open water.
Responsible encounters
The dugong controls every encounter
A sighting is not permission to close the distance. The best encounter is passive: observe first, reduce pressure and let the animal feed, breathe, approach or leave on its own terms.
Vanuatu's Fisheries Act protects marine mammals from harm and harassment. Targeted commercial marine-mammal viewing requires the relevant Fisheries approval, while research and drone work can involve separate permits, aviation requirements and customary-owner agreement.
Before any boat or in-water encounter, read the Vanuatu dugong encounter guidelines for swimmers, snorkellers, divers, boats, photographers and drone operators. For the wider travel picture, compare places where you may swim with dugongs worldwide and what to expect.
Do not chaseNever pursue, touch, feed, surround, intercept or block the route to the surface.
Stay quiet and horizontalIf already in the water, minimise splashing and never freedive down toward the animal.
Slow the vesselUse a dedicated lookout, reduce to no wake around shallow habitat and never anchor on seagrass.
Keep scuba incidentalIf a dugong passes during a normal dive, stay calm and together. Do not turn the dive into a pursuit.
Protect sensitive placesDo not publish exact calf, feeding or resting locations simply to create a visitor waypoint.
Experience Moso Island
Come for the reefs. Treat a dugong as a privilege.
Havannah Harbour should be chosen for its warm-water diving, coral reefs, walls, island passages and local character. Dugongs are present and a sighting is genuinely possible, but they are wild and unpredictable, so no trip can guarantee when or where one will appear.
The honest promise: come for a complete Vanuatu dive holiday. Treat any dugong encounter as an extraordinary privilege, never as a scheduled inclusion.
Research base
Principal sources for this local guide
This page distinguishes direct observations, structured community knowledge, habitat measurements and ecological inference. Last evidence review: 5 August 2026.
1989 SPREP The Status of the Dugong in Vanuatu Questionnaires, aerial reconnaissance and the connected-habitat hypothesis. 1990 AIMS survey Seagrass Communities of Vanuatu The detailed 1988 botanical field descriptions from Moso. 2017–2018 Cefas Efate seagrass and water quality Later monitoring that included Moso within the north Efate network. 2022 VESS Report on the aerial survey of dugongs The targeted North Efate and Havannah Harbour drone work. Bathymetry SPC Havannah Harbour survey chart The physical basis for distinguishing the deep basin from shallow margins. 2025 CMS Global Assessment of Dugong Status Current international context and Vanuatu's unresolved population status.
Visitor guidance: VESS tourism operator code VESS tourist interaction guide.
Frequently asked questions
Havannah Harbour dugong questions
Short answers to the questions that matter most—without filling the evidence gaps with guesses.
Are there dugongs in Havannah Harbour?
Yes. Historical records show use of the wider Moso–Havannah–Lelepa system, and a 2021 VESS drone survey photographed at least one live dugong inside its Havannah Harbour block. That establishes occurrence, not a resident population or reliable encounter rate.
How many dugongs live around Moso Island?
No defensible number exists. Reports, sightings and overlapping drone images cannot be added together as unique animals without photo-identification, repeat survey effort or another population method.
Why do dugongs use Havannah Harbour?
The strongest explanation is the combination of seagrass food, relative shelter, shallow margins beside deeper water and passages connecting several habitat patches. It is an evidence-supported habitat explanation, not a result from tracking individual harbour dugongs.
Is there a best season to see dugongs near Moso?
No scientifically established local season exists. Tide, wind, water clarity, food, disturbance and movements outside the harbour can all affect presence or detectability. A seasonal claim requires comparable observations across at least a full year.
Where is the exact dugong spot?
There is no single spot. The useful ecological unit includes shallow margins, reef edges, passages and deeper harbour water around Moso, Lelepa and Efate. Exact sensitive locations should not be published as chase points.
Can visitors swim or snorkel with dugongs here?
Only if a lawful, customary-owner-supported operation has the current approvals and the animal remains relaxed under strict, animal-led limits. This page does not advertise a targeted dugong swim. Never enter the water simply because an animal has surfaced nearby.
Can you scuba dive with dugongs?
A planned scuba interaction can prolong pursuit and is not the preferred method. If a dugong appears during an ordinary dive, remain calm, keep the group together and let it control the distance. Do not descend toward it or turn to follow.
Is a dugong sighting included in Abyss Vanuatu trips?
No. Both the Vanuatu Long Weekend Dive Escape and New Year Dive Adventure are complete dive holidays in their own right. Dugongs are present in Havannah Harbour and a sighting is a genuine possibility, but they are wild and unpredictable, so an encounter is never an inclusion or guarantee.
Are Havannah Harbour and Havannah Bay the same place?
Both names are used locally and in published or tourism material for the north-west Efate setting. This guide uses Havannah Harbour for the connected water body beside Efate, Moso and Lelepa rather than treating one named bay as the whole habitat.
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