Sainte-Marie Island
Madagascar · Indian Ocean
Île Sainte-Marie sits off Madagascar's northeast coast and doubles as a humpback whale nursery every July to September. Its reefs remain largely unexplored, and the bay shelters intact 17th-century pirate ship wrecks beneath clear tropical water.
How this reef is doing
ⓘ How we measure thisReef state
Live coral covers 38% of this reef.
Coral cover
Fish life
Heat
Fishing
Open to fishing, and the water is fairly quiet.
Sources · MERMAID and the survey teams · Global Fishing Watch and reef gravity
Coral cover over time
Live coral cover, by survey year
Across 3 survey years from 2015 to 2025, live coral cover here has fallen from 43% to 38%. Every point is a real survey reading, never a projection.
Live coral cover, percent by year
| Year | Coral cover |
|---|---|
| 2015 | 43% |
| 2019 | 43% |
| 2025 | 38% |
What you will see
19 species across the dive sites here
Crested Drongo
Seen Oct 2024
at Cap Est Reef
Least concern
Malagasy Kestrel
Seen Aug 2024
at Whale Nursery
Least concern
Indo-Pacific Rock-Boring Urchin
Seen Aug 2024
at Cap Est Reef
Humpback whale
Seen Aug 2024
at Whale Nursery
Least concern
Crown Squirrelfish
Seen Jul 2024
at Pirate Wreck
Least concern
Vagabond Butterflyfish
Seen Jul 2024
at Cap Est Reef
Least concern
Indian Lionfish
Seen Apr 2024
at La Buse Reef
Least concern
Red Fody
Seen Mar 2024
at Whale Nursery
Least concern
Moorish idol
Seen Mar 2024
at Cap Est Reef
Least concern
Bottlenose dolphin
Seen year round
at Whale Nursery
Least concern
Glassfish (Indian glassy fish)
Seen year round
at Pirate Wreck
Least concern
Great barracuda
Seen year round
at La Buse Reef
Least concern
Green sea turtle
Seen year round
at Whale Nursery
Least concern
Hawksbill sea turtle
Seen year round
at La Buse Reef
Critically endangered
Lionfish
Seen year round
at Pirate Wreck
Least concern
Moray eel
Seen year round
at Pirate Wreck
Least concern
Napoleon wrasse
Seen year round
at Cap Est Reef
Endangered
Whale shark
Seasonal visitor
at La Buse Reef
Endangered
Yellowfin tuna
Seasonal visitor
at Cap Est Reef
Least concern
Dive sites
Whale Nursery
humpback whale · bottlenose dolphin · green sea turtle · crested drongo
Cap Est Reef
napoleon wrasse · yellowfin tuna · moorish idol · crested drongo
Pirate Wreck
lionfish · glassfish (indian glassy fish) · moray eel · crested drongo
La Buse Reef
whale shark · great barracuda · hawksbill sea turtle · crested drongo