Scuba Season

Grey reef shark

Carcharhinus amblyrhynchos

Sighting evidence at St John's Reef, Brothers Islands

Grey reef shark

Photo: Daniel Benák · © all rights reserved

One of the Indo-Pacific's most abundant reef sharks and a defining presence on healthy coral reefs. Grey reef sharks are mid-water patrollers, typically seen in small groups or alone along reef edges and drop-offs. They are curious rather than aggressive, often circling divers at a consistent distance. A distinctive threat display — arched back, depressed pectoral fins, exaggerated swimming — signals discomfort if divers approach too closely. Near threatened; their numbers have declined sharply in areas with intensive fishing.

Evidence at this site

0 records within 25 km

Confidence: low

No date on file

Seasonality

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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