A deep tropical sea in the south-west Philippines, guarding the pristine Tubbataha Reefs at its heart.
Area
260,000 km²
Ocean basin
Pacific
Location
Home of the Tubbataha Reefs
Average depth
about 1,400 m
Maximum depth
about 5,580 m
Salinity
~34 ppt
Temperature
Warm, 27–30°C
Region
South-western Philippines
About the Sulu Sea
The Sulu Sea is a deep basin enclosed by the Philippine islands and the Sulu Archipelago. At its heart, far from any coast, rise the Tubbataha Reefs — a UNESCO-listed marine park whose isolation keeps its coral, sharks, turtles and seabirds in near-pristine condition. Below, the basin plunges past 5,000 m.
Did you know?
At its centre lie the Tubbataha Reefs — a UNESCO World Heritage marine park so remote it stays almost untouched.
Highlights
- Guards the Tubbataha Reefs
- A deep, enclosed tropical basin
- A near-pristine marine wilderness
Photo gallery
Life in the Sulu Sea
Creatures, seabirds and marine plants — including some of the rarest and strangest — that live in these waters.
Creatures of the deep
Green sea turtle
The only sea turtle that grazes seagrass as an adult, which tints its fat green.
Clownfish
Lives unharmed among an anemone’s stinging tentacles; every clownfish is born male.
Moray eel
A reef ambush predator with a hidden second set of jaws in its throat to drag prey down.
Nudibranch (sea slug)
Dazzlingly coloured sea slugs that steal stings — and even sunlight — from the food they eat.
Mimic octopus
An octopus that impersonates sea snakes, lionfish and flatfish on demand.
Seabirds
Frigatebird
A pirate of tropical skies; the male balloons a scarlet throat pouch to court mates.
Marine plants & algae
Coralline algae
Stony pink algae that cement coral reefs together and help them grow.
Mangrove
Salt-tolerant coastal trees whose tangled roots shelter young fish and buffer storms.
Surface & deep in the Sulu Sea
The sea is warm where the Sun reaches it and cold far below. Flip between the sunlit surface and the deep water to feel the difference — these are typical figures for a sea.
Sunlit surface
22°C
typical surface temperature
Seas warm strongly at the surface in summer, but their deeper water stays cold and still — the sunlight simply never reaches it.
Recorded range for the Sulu Sea: Warm, 27–30°C