As of today, out of season, returns ~March. Earth Exhibit tracks the live conditions and flags it the moment it is on.
Multispecific mass-spawning of reef-building corals occurs at sites across Bunaken National Marine Park.
Dozens of scleractinian species (commonly Acropora, Montipora, Porites and others) release gamete bundles on coordinated nights, producing ephemeral slicks and brief, intense reproductive activity that is predictable by lunar phase and seasonal temperature changes.
Where to see it
A taste of where to see it. The full map, exact coordinates and the best timing for each spot live in the app.
| Viewing spots |
|---|
| Bunaken Village Pier (Bunaken Island) |
| Meras Reef / Manado Bay (common research/diver observation site) |
| + 1 more spot, with exact coordinates and timing, in the app → |
This is the short version
This page shows a taste. The app has the full list of where to see this, the exact timing, and live conditions for 1,000+ natural phenomena worldwide, so you know the moment one is genuinely worth the trip.