STAR: An integrated and standardized procedure to evaluate the ecological status of coralligenous reefs

Coralligenous reefs represent one of the most important coastal ecosystems of the Mediterranean Sea, and their ecological quality must be assessed under the Marine Strategy Framework Directive to evaluate seafloor integrity. An effective standardized monitoring protocol is urgently needed in order to compare data at the Mediterranean scale and to plan efficient management and intervention programmes. This paper aims to: (a) review methods used to study shallow coralligenous reefs to propose a method able to optimize sampling effort; (b) select the most effective ecological descriptors to evaluate the responses of coralligenous assemblages to anthropogenic stress; and (c) synthesize available information in an integrated and standardized procedure. Ninety-five scientific papers dealing with shallow coralligenous reefs were found. Among these, 52 papers reporting detailed descriptions about sampling methods were selected to identify methodologies and ecological descriptors suitable for monitoring purposes. Downstream of the bibliographic review, an integrated and standardized procedure, named STAR (STAndaRdized coralligenous evaluation procedure), was proposed to assess the ecological quality of coralligenous reefs. STAR was tested on coralligenous reefs at 12 sites, six of them subjected to high human pressure and six located in areas characterized by low human pressure. Significant differences between the two conditions were detected for all the ecological descriptors selected, thus confirming the effectiveness of STAR in the assessment of ecological quality of coralligenous reefs.