Dense populations of the red gorgonian Paramuricea clavata shape marine animal forests in the Mediterranean Sea, characterizing the seascapes of coralligenous habitats. However, the understorey of its forests and the ecological processes that they promote are still little known.

This study investigated the abundance and composition of epibenthic assemblages inside and outside P. clavata forests across the central and western Mediterranean Sea, by applying a multifactorial sampling design.

The results show that despite the large variability in the structures of epibenthic assemblages at local and regional scales, the gorgonian understoreys share some common features, such as higher abundances of calcareous builder organisms and reduced invasion by the non-indigenous alga Caulerpa cylindracea, compared with the adjacent unforested rocky bottoms.

The authors state that P. clavata forests may enhance bioconstruction processes and increase resistance and resilience of the benthic assemblages in the Mediterranean coralligenous habitats. It is suggested that this species and its forests, together with their understoreys, should be considered as essential elements of the ecology of the Mediterranean Sea, and therefore worthy of specific and effective protections measures.

The authors state that conservation strategies should reduce the risk of mechanical damage by regulating fishing activities, anchorages, and scuba diving where gorgonian forests are present.

Ponti M, Turicchia E, Ferro F, Cerrano C, Abbiati M (2018) The understorey of gorgonian forests in mesophotic temperate reefs. Aquatic conservation: marine and freshwater ecosystems DOI: 10.1002/aqc.2928