Part of our Raja Ampat guide →
Biodiversity by the numbers
- Region
- The Coral Triangle, spanning Indonesia, the Philippines and neighbouring seas
- Hard corals
- Roughly 550 to 600 species recorded in Raja Ampat
- Share of world corals
- Around three quarters of known reef-building coral species
- Reef fish
- Over 1,500 species recorded across the archipelago
- Cape Kri
- 374 fish species counted on one 90-minute dive in 2012
- Sea turtles
- Four of the world's seven species use these waters
What Is the Coral Triangle?
A roughly triangular stretch of tropical ocean spanning Indonesia, Malaysia, the Philippines, Papua New Guinea, Timor-Leste and Solomon Islands. It holds the highest concentration of reef-building coral and reef fish species anywhere measured, and Raja Ampat sits at its most species-rich corner.
The richness is not an accident of geography alone. Raja Ampat lies in the path of the Indonesian Throughflow, the current system moving Pacific water toward the Indian Ocean, which delivers a constant supply of nutrients and larvae across a huge variety of reef habitats.
That combination of habitat variety and water movement is why the same archipelago produces both crowded pelagic corners and quiet muck-diving bays within a few hours of each other.
Does Raja Ampat Really Hold 75% of the World's Coral Species?
The figure is well founded but should be stated carefully. Rapid ecological assessments led by Conservation International and The Nature Conservancy recorded roughly 550 to 600 hard coral species in Raja Ampat, which is around three quarters of all described reef-building coral species. It is a survey result for known species, not a fixed count.
| Claim | How it is usually stated | How we state it | Source basis |
|---|---|---|---|
| Coral species | 75% of the world's coral species | Around three quarters of known reef-building coral species, roughly 550-600 recorded | Conservation International and Nature Conservancy rapid assessments, 2002-2003 |
| Reef fish | 1,500+ species | Over 1,500 reef fish species recorded archipelago-wide | Cumulative survey records for Raja Ampat |
| Cape Kri | World record fish count | Highest recorded single-dive count: 374 species in 90 minutes, 2012 | Dr Gerald Allen's survey dive, widely reported in dive press |
| Sea turtles | Six of seven species | Four of seven species: green, hawksbill, leatherback, olive ridley | Regional monitoring and survey records |
Where a figure is a survey result rather than a fixed count, we say so. Numbers move as taxonomy and monitoring are revised.
Two things follow. First, the denominator moves: as taxonomy is revised, the percentage shifts slightly, which is why credible sources say "around 75 per cent" rather than a precise number. Second, the surveys were rapid assessments of selected sites, so the true figure is more likely under-counted than inflated.
We state it as roughly three quarters of the world's known reef-building coral species. That is defensible, and it is still the most remarkable coral statistic in the world.
What Is the Cape Kri Fish Record?
In 2012 the ichthyologist Dr Gerald Allen counted 374 fish species during a single 90-minute dive at Cape Kri in the Dampier Strait, the highest single-dive count recorded. It is a record of one scientist's count on one dive rather than an official standing measurement, and it has not been surpassed since.
The number is meaningful because of who made it and how: a specialist who could identify what most divers would swim past. An ordinary guest at Cape Kri sees a busy, current-swept reef corner, not 374 labelled species.
We describe it as the highest recorded single-dive fish count rather than an accredited world record, because the underlying claim comes from published dive reports and Dr Allen's own survey work rather than a formal register.
Which Sea Turtles Live in Raja Ampat?
Four of the world's seven sea turtle species use these waters: green, hawksbill, leatherback and olive ridley. Green and hawksbill turtles are the ones guests routinely see feeding on shallow reefs. Leatherback and olive ridley records are far scarcer, and nesting beaches are protected and monitored.
You will sometimes see "six of seven species" attached to Raja Ampat. Four is the number the survey and monitoring literature supports for the archipelago, so that is what we use.
Turtles nest on quiet sand beaches across the archipelago, and several communities run nest protection schemes. Nesting sites are not a scheduled excursion; if your expedition team offers one, it is because local partners have agreed to it.
Why Are These Reefs Still in Good Condition?
A combination of remoteness, a network of marine protected areas, and customary Papuan reef tenure that gives communities a direct stake in enforcement. Local patrols and no-take zones have curbed destructive fishing, and the strong currents that feed the reefs also help buffer them against heat stress.
None of that makes the reefs invulnerable. Bleaching, plastic and fishing pressure all reach Raja Ampat, and visitor numbers have grown quickly. The marine park conservation levy every visitor pays funds patrols and management, which is why we treat it as part of the fare rather than a nuisance charge. See what a Raja Ampat cruise costs.
Reef-safe sunscreen matters here for a specific reason, not as a general gesture: oxybenzone and octinoxate are linked to coral damage, and Raja Ampat's healthiest hard coral grows within a metre or two of the surface, exactly where snorkellers float for hours. Use non-nano zinc, or cover up with UPF fabric instead. More on how we think about this in responsible travel.
Can Guests Take Part in Reef Monitoring?
On several ships, yes. Expedition naturalists involve guests in reef health observations, manta identification from spot patterns, and turtle sighting logs. It is genuine data collection rather than an activity, and it changes how people look at a reef, but it is offered by some operators and not others.
Manta identification works because the spot pattern on each animal's underside is unique, so a guest photograph can be matched against regional databases. Our citizen science page explains what these programmes involve more broadly.
Is This Based on Your Own Diving?
No. We have not been to Raja Ampat; our own voyage is in 2027. What is on this page comes from published survey work, from clients who have travelled with these operators and reported back, and from an advisor colleague's detailed account of a recent voyage. We will rewrite it once we have seen these reefs ourselves.
The distinction matters most on a page like this one. The biodiversity figures are research; the observations about what guests actually notice underwater are client feedback, and we label them as such.
Coral Triangle questions
How many coral species are in Raja Ampat?
Rapid ecological assessments recorded roughly 550 to 600 reef-building coral species, around three quarters of all described species worldwide.
Is Cape Kri really a world record dive site?
Dr Gerald Allen counted 374 fish species on a single 90-minute dive there in 2012, the highest single-dive count recorded. It is a published survey result rather than an accredited register entry, and it still stands.
How many sea turtle species are found in Raja Ampat?
Four of the world's seven: green, hawksbill, leatherback and olive ridley. Green and hawksbill are the two guests commonly see.
Why do Raja Ampat reefs remain healthier than most?
Remoteness, a network of marine protected areas, customary community reef tenure with local enforcement, and strong nutrient-rich currents that help buffer heat stress.