Scuba Season

Scalloped Hammerhead Shark

Sphyrna lewini

Sighting evidence at Passe Houareau, Aldabra Atoll

Scalloped Hammerhead Shark

Photo: Bruno Mels · © all rights reserved

Scalloped hammerheads form schools of dozens to hundreds at Aldabra's channels, gathering along thermocline boundaries where temperature differentials concentrate prey. Their distinctive hammer-shaped cephalofoil dramatically increases the surface area of electroreceptive organs, allowing them to detect stingrays buried beneath sand at distances of over a metre. Populations here represent one of the last large aggregations in the Indian Ocean, making Aldabra critical for regional population viability.

Evidence at this site

0 records within 25 km

Confidence: low

No date on file
How is this calculated?

Sighting evidence is compiled from iNaturalist observation records within a set proximity radius, filtered for quality-grade observations. “Last confirmed” is the date of the most recent research-grade record. Record count covers a rolling 24-month window. Confidence reflects record count, recency, and consistency of seasonal signal.

Also seen at other sites