Derawan Archipelago
Indonesia · East Kalimantan
Derawan is one of the only places on Earth where reef manta rays are resident year-round. The Marine Megafauna Foundation has identified 155 individual mantas here — and 24 percent of the females have been observed pregnant, the only site in East Borneo where this is documented. With 500 plus coral species and 800 plus reef fish species the archipelago sits in the highest-diversity marine zone on the planet. The 285,549 hectare Berau MPA was declared in 2016 and active enforcement patrols with radar monitoring began in 2023.
How this reef is doing
ⓘ How we measure thisReef state
Sangalaki Island is one of a handful of places worldwide with year round resident reef manta rays — and the only site in East Borneo where pregnant females regularly appear. Hard coral cover has recovered close to 2003 levels after the 2010-2011 bleaching impact. Enforcement patrols with 24/7 radar monitoring began in 2023; seizures and prosecutions for blast fishing increased sharply in 2024.
Coral cover
Fish life
Heat
Warmer than usual right now, but not hot enough to bleach.
Fishing
Some fishing is allowed here, in marked zones.
Sources · Reef survey · NOAA Coral Reef Watch · Global Fishing Watch and reef gravity
Coral cover over time
Live coral cover, by survey year
Across surveys in 2003 and 2023, live coral cover here has risen from 32% to 33%. Every point is a real survey reading, never a projection.
Live coral cover, percent by year
| Year | Coral cover |
|---|---|
| 2003 | 32% |
| 2023 | 33% |
What you will see
14 species across the dive sites here
Nudibranch
Seen 5 months ago
at Derawan House Reef
Green sea turtle
Seen 5 months ago
at Derawan House Reef
Least concern
Pygmy seahorse
Seen Jul 2025
at Derawan House Reef
Bluefin Trevally
Seen year round
at Barracuda Point, Kakaban
Least concern
Great Barracuda
Seen year round
at Barracuda Point, Kakaban
Least concern
Grey Reef Shark
Seen year round
at Barracuda Point, Kakaban
Endangered
Whitetip Reef Shark
Seen year round
at Barracuda Point, Kakaban
Vulnerable
Blue-ringed octopus
Seasonal visitor
at Derawan House Reef
Flamboyant cuttlefish
Seasonal visitor
at Derawan House Reef
Frogfish
Seasonal visitor
at Derawan House Reef
Ghost pipefish
Seasonal visitor
at Derawan House Reef
Scalloped Hammerhead
Seasonal visitor
at Barracuda Point, Kakaban
Critically endangered
Spanish dancer nudibranch
Seasonal visitor
at Derawan House Reef
Spotted Eagle Ray
Seasonal visitor
at Barracuda Point, Kakaban
Endangered