scubaseason

Indian Ocean Humpback Dolphin

Sousa plumbea

Sighting evidence at Spinner Dolphin Pass, Kalpitiya

The less-celebrated but equally fascinating humpback dolphin uses the seagrass meadows fringing the pass as a hunting ground for small flatfish and crustaceans, its distinctive dorsal hump and slower surface behaviour making it immediately distinguishable from its faster-moving neighbours. Listed as Vulnerable by the IUCN, this species faces severe pressure from coastal fishing and boat strikes throughout its range, making the Kalpitiya population an important conservation population in Sri Lankan waters. Sightings are best during quiet early-morning transits through the shallower seagrass patches.

Evidence at this site

No confirmed records on file at this site

Indian Ocean Humpback Dolphin 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.