<i>NAMBER</i> : A biotic index for assessing the ecological quality of mesophotic biogenic reefs in the northern Adriatic Sea

The aim of the present study was to propose a biotic index (North Adriatic Mesophotic BiogEnic Reefs, NAMBER) suitable for assessing ecological quality mesophotic biogenic reefs northern continental shelf based on photographic sampling. At each 20 sites, degree bioconstruction (expressed as percentage cover crustose coralline algae), α-diversity mean number taxa), and sensitivity human disturbance climate change (based literature data expert judgement) benthic assemblages were selected descriptors combined in NAMBER index, using best values that three metrics can currently achieve studied region reference. highlighted there large spatial heterogeneity among high variability obtained by NAMBER, ranging from bad high. indicates lying furthest coast, under substantially lower anthropogenic pressure, have generally higher status environmental quality. However, clear geographical pattern did not emerge, close together often had different qualities. which combines descriptors, accordance with requirements European Marine Strategy Framework Directive, represents specific adaptation Sea multimetric previously developed north-western Mediterranean Sea, capitalizing previous knowledge research efforts. This provides an effective standardized tool monitoring programmes impact assessments lays foundation ecosystem-based management conservation this basin.