As one of the flagship achievements of Work Package 5 – Management tools for sustainable conservation of sponge ecosystems of the Biodiversa+ project SponBIODIV, these assessments provide the first standardized evaluation of extinction risk for this ecologically important but historically overlooked group of marine organisms.
The initiative brought together 24 sponge experts from across the Mediterranean, who participated as assessors, contributors, facilitators/compilers and reviewers under the IUCN Red List assessment process. Together, they evaluated 24 Mediterranean sponge species, including 21 endemic species, following the internationally recognised IUCN Red List Categories and Criteria.
The assessments identified four commercially exploited bath sponge species as Endangered, while nearly half of the evaluated species were classified as Data Deficient, highlighting major knowledge gaps and the need for further research and long-term monitoring.
Beyond assessing extinction risk, this work establishes the first robust scientific baseline for Mediterranean sponge conservation and demonstrates the value of coordinated international collaboration. The results are already supporting evidence-based conservation policies, including the recent strengthening of legal protection for Mediterranean sponges under the Barcelona Convention.
The Mediterranean sponge assessments are available on the IUCN Red List of Threatened Species here: https://www.iucnredlist.org/
