scubaseason

Atlantic Halibut

Hippoglossus hippoglossus

Sighting evidence at Agdenes Lighthouse Reef, Trondheim Fjord

Juvenile Atlantic halibut, the world's largest flatfish, are occasionally encountered resting on the sand and gravel flats adjacent to the Agdenes reef, particularly in autumn when cold-water upwelling brings nutrient pulses inshore. Adults can exceed 3 m and 300 kg, and their mottled brown camouflage makes them virtually invisible against the seabed. Norway hosts one of the few remaining viable wild Atlantic halibut populations in the Northeast Atlantic.

Evidence at this site

No confirmed records on file at this site

Atlantic Halibut 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.