A system of marine animal bioconstructions in the mesophotic zone along the Southeastern Italian coast

Abstract

A widespread and diversified mesophotic system of carbonate bioconstructions along the Southern Adriatic and Ionian Italian coasts is described, providing new data on the distribution, structure and associated megabenthic assemblages of mesophotic Mediterranean bioconstructions. The bioconstructions were detected at six different sites off the coasts of Apulia, in presence of marked morphological escarpments, developing on a basal substrate consisting of meso-Cenozoic carbonate rocks. Two biogenic structure types were observed, one mainly built by the nonsymbiotic scleractinians Phyllangia americana mouchezii and Polycyathus muellerae, at depths between approximately 35 and 55 m, and the other by the oyster Neopycnodonte cochlear, at depths from approximately 40 to 70 m. A total of 52 taxa of megabenthic invertebrates, belonging to 6 phyla, were found on the surface of the mesophotic bioconstructions, thus confirming the role of biodiversity hotspots of these carbonate structures. Megabenthic assemblages showed a remarkable heterogeneity both in pattern of species and abundance, probably depending on both the morphological differences of the seabed and the life traits of the single species. Primary bioconstructors seemed to influence the associated community pattern. This peculiar system deserves sound conservation measures in the light of the holistic ecosystem approach for the management of coastal marine areas.

Characterization of the Coralligenous Formations from the Marine Protected Area of Karaburun-Sazan, Albania

“…The Albanian coralligenous showed some peculiarities, since three sponge species recorded during the present study (Petrobiona massiliana, Hexadella racovitzai, and Merlia normani) were not included in the Apulian coralligenous biodiversity checklist [61], although H. racovitzai has been recently described within Apulian mesophotic biogenic reefs [7][8][9].…”

“…The associated faunal component plays an important role in structuring these bioconstructions. When light conditions are not suitable to support algal communities, animals can take over the role of the main builders, giving rise to mesophotic reefs built by scleractinians or oysters [7][8][9]. There is usually a clear spatial separation between substrates dominated by algae or animals, thus creating a complex mosaic of facies in which few dominant species alternate even at a small scale.…”

A Dataset of Benthic Species from Mesophotic Bioconstructions on the Apulian Coast (Southeastern Italy, Mediterranean Sea)

“…This dataset includes previously published information [12][13][14] complemented by more recent data presented here for the first time, with an overall sampling period ranging from 2017 to 2023. The six study sites were selected based on preliminary geophysical investigations and ROV images resulting from a previous research project (BIOMAP) aimed at studying bioconstructions along the Apulian coast.…”

“…The dataset includes records gathered from 6 sites along the Apulian coast (Southeastern Italy), where our research [12][13][14] revealed the occurrence of large bioconstructions. The sites, located from north to south, are as follows: the Tremiti Islands (TRM); Monopoli (MON); Capitolo (CAP); San Foca (SFC); Otranto (OTR); and Santa Maria di Leuca (SML) (Figure 1).…”

“…These mesophotic bioconstructions are built by invertebrates with calcareous skeletons and have a thicker and looser texture than calcareous algae bioconstructions [9,10]. Similarly to the latter, the invertebrate bioconstructions support rich and heterogeneous benthic communities [11][12][13][14].…”