Shallow-water marine organisms are among the first to suffer from combined effects of natural and anthropogenic drivers. The orange coral Astroides calycularis is a shallow-water bioconstructor species endemic to the Mediterranean Sea. Although this species raises conservation interest, information about the threats to its health is scant.

This study investigated the health status of A. calycularis at five locations in northwestern Sicily along a gradient of cumulative human impact and the most probable origin of the threats to this species, including anthropogenic land-based and sea-based threats.

The results show that cumulative human impact appeared inversely related to the performance of A. calycularis at population, colony, and polyp levels. The reduction in polyp length can limit the reproductive performance of A. calycularis, while the decrease of percent cover and colony area is expected to impair its peculiar feeding behavior by limiting the exploitable dimensional range of prey and, ultimately, reef functioning.

The authors conclude that this habitat-forming species appeared susceptible to anthropogenic pressures, suggesting the need to re-assess its vulnerability status.

Prada et al. (2019) Anthropogenic impact is negatively related to coral health in Sicily (Mediterranean Sea). Scientific Reports 9:13469.