Temperate mesophotic reefs (circalittoral and offshore hard/firm habitats), host complex three-dimensional animal forests and are vulnerable habitats protected by international agreements.

This study developed a multiparametric index (Mesophotic Assemblages Conservation Status, MACS) to evaluate and monitor the environmental status of these ecosystems.

The index was tested in underwater video transects recorded with a Remotely Operated Vehicle (ROV) along the Ligurian and Tyrrhenian Seas, offering the chance to test it on a large geographic scale and various ecological settings subjected to different human pressures.

The study shows that MACS index showed a high potentiality to distinguish among a wide range of environmental conditions, with local critical situations mainly related to high fishing pressure. The authors highlight that, in comparison to other indices, MACS is based on a larger number of parameters, resulting in a higher ability to disentangle natural and anthropogenic factors, leading to a better interpretation of local situations.

It is concluded that this tool contributes to the requirements for the monitoring of these marine environments, set by the EU Marine Strategy Framework Directive, the Habitat Directive, and the guidelines of the Integrated Monitoring Assessment Programme of the Mediterranean Sea and Coast of the Barcelona Convention.

https://www.sciencedirect.com/science/article/pii/S1470160X19301372

Enrichetti et al. (2019) Assessing the environmental status of temperate mesophotic reefs: A new integrated methodological approach. Ecological Indicators 102:218-229.