scubaseason

Blue Shark

Prionace glauca

Sighting evidence at Sagres Wrecks, Algarve

Blue sharks appear off Sagres from May through October, drawn by the cape's upwelling productivity and the schools of mackerel and sardines that aggregate there. As highly migratory oceanic apex predators they are critical to regulating pelagic fish populations across the North Atlantic, yet remain among the most heavily fished shark species worldwide. Their appearance on wreck dives — circling curiously at the edge of visibility — is one of the signature encounters of the Algarve summer season.

Evidence at this site

No confirmed records on file at this site

Blue 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