scubaseason

Barrel Sponge

Spongia officinalis

Sighting evidence at Sponge Gardens, Djerba

The commercial bath sponge — historically harvested to near-local extinction across Tunisia — has recovered significantly at this protected site, with individuals reaching 40 centimetres diameter representing decades of growth. Sponges here filter thousands of litres of water daily, playing an outsized role in local nutrient cycling and water clarity. They provide microhabitat for brittlestars, small fish, and a variety of crustaceans living inside their oscula.

Evidence at this site

No confirmed records on file at this site

Barrel Sponge 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