Mnemba Atoll
Tanzania · Zanzibar
Mnemba Atoll off Zanzibar's northeast coast is Tanzania's most accessible coral diving — a small protected atoll with dolphins, turtles, and reef fish in clear water, framed by Zanzibar's spice island culture.
How this reef is doing
ⓘ How we measure thisReef state
Zanzibar's marquee reef has lost substantial cover. Dolphins and turtles still consistent.
Coral cover
Fish life
Heat
No unusual heat right now.
Fishing
Some fishing is allowed here, in marked zones.
Sources · MERMAID and the survey teams · NOAA Coral Reef Watch · Global Fishing Watch and reef gravity
Coral cover over time
Live coral cover, by survey year
Across 6 survey years from 2019 to 2026, live coral cover here has fallen from 50% to 26%. Every point is a real survey reading, never a projection.
Live coral cover, percent by year
| Year | Coral cover |
|---|---|
| 2019 | 50% |
| 2022 | 63% |
| 2023 | 51% |
| 2024 | 27% |
| 2025 | 43% |
| 2026 | 26% |
What you will see
22 species across the dive sites here
Rough-Scaled Plated Lizard
Seen 24 days ago
at Mnemba South Wall
Least concern
Bottlenose dolphin
Seen 25 days ago
at Kichwani
Near threatened
Red-Knobbed Sea Star
Seen 25 days ago
at Mnemba South Wall
Green turtle
Seen 1 month ago
at Kichwani
Least concern
House Crow
Seen 1 month ago
at Mnemba South Wall
Least concern
Leaf scorpionfish
Seen 3 months ago
at Wattabomi
Least concern
Stonefish
Seen 5 months ago
at Wattabomi
Least concern
Porcelain crab
Seen 5 months ago
at Wattabomi
Snowflake moray
Seen 5 months ago
at Wattabomi
Least concern
Octopus
Seen 5 months ago
at Wattabomi
Least concern
Giant Barracuda
Seen May 2025
at Mnemba South Wall
Least concern
Napoleon wrasse
Seen Nov 2024
at Kichwani
Endangered
Bluefin trevally
Seen Nov 2024
at Kichwani
Least concern
Frogfish
Seen Oct 2024
at Wattabomi
Whitetip reef shark
Seen Oct 2024
at Kichwani
Vulnerable
Blacktip Reef Shark
Seen year round
at Mnemba South Wall
Vulnerable
Blue spotted stingray
Seen year round
at Wattabomi
Hawksbill Sea Turtle
Seen year round
at Mnemba South Wall
Critically endangered
Hawksbill turtle
Seen year round
at Kichwani
Critically endangered
Scorpionfish
Seen year round
at Kichwani
Bumphead Parrotfish
Seasonal visitor
at Mnemba South Wall
Vulnerable
Whale shark
Rare sighting
at Kichwani
Endangered
Dive sites
What divers say
Dive in the morning, walk Stone Town in the afternoon, that's the trip.
Good to know
Marine conservation fee
Modest fee collected at the atoll.