Flat Oyster

Ostrea edulis

Sighting evidence at Borj el Kastil, Djerba

Colonies of flat oysters — now rare across much of the Mediterranean due to overharvesting — grow undisturbed on the protected masonry faces, serving as critical filter feeders that improve local water clarity. Their shells provide attachment surfaces for sponges, hydroids, and bryozoans that further increase biodiversity on the site. The species' recovery here reflects the passive protection offered by the site's cultural heritage status.

Evidence at this site

0 records within 25 km

Confidence: low

No date on file

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.