scubaseason
Critically Endangered· population decreasing· assessed 2019

Scalloped Hammerhead Shark

Sphyrna lewini

Sighting evidence at Tablas Strait Drift, Romblon

Scalloped Hammerhead Shark

Photo: Kris Mikael Krister · CC BY

Scalloped hammerhead sharks patrol the deeper ridges of the Tablas Strait during the cooler months of November through May, when cold upwelling water concentrates the squid and fish they feed on. Schools of juveniles occasionally appear in the mid-water column during early morning dives, circling in formation before dispersing at full daylight. The strait's nutrient upwelling creates one of the few reliable hammerhead aggregation sites in the Visayas region.

Evidence at this site

No confirmed records on file at this site

Scalloped Hammerhead Shark is listed as a curated species here based on historical reports.

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