Dusky grouper

Epinephelus marginatus

Sighting evidence at Il Medico, Ustica Island

Photo: erythro07 · CC BY-NC

Ustica's dusky grouper population is one of the densest in the Mediterranean, a direct consequence of over 40 years of marine reserve protection in Zone A (no-take, no-entry without permit). Adult males here can exceed 80 cm and 15 kg — sizes almost never encountered in unprotected Mediterranean waters. As apex predators, they regulate populations of octopus, bream, and damselfish, maintaining the structural balance of the reef community. Their tolerance of divers makes Ustica one of the best places in Europe to observe natural grouper behaviour.

Evidence at this site

21 records within 25 km

Confidence: medium

Last confirmed Jul 2025

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.

Dusky grouper

Evidence at this site

Seasonality

Also seen at other sites