Distribution and Characterization of Deep Rhodolith Beds off the Campania coast (SW Italy, Mediterranean Sea)

• Published in: Plants (Basel) Vol. 9; no. 8; p. 985
• Main Authors: Rendina, Francesco, Kaleb, Sara, Caragnano, Annalisa, Ferrigno, Federica, Appolloni, Luca, Donnarumma, Luigia, Russo, Giovanni Fulvio, Sandulli, Roberto, Roviello, Valentina, Falace, Annalisa
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 04-08-2020; MDPI
• Subjects: Algae; Aquaculture; Associated species; Biodiversity; biogenic habitats; Cameras; coralline algae; Habitats; maerl; Remotely operated vehicles; rhodolith beds; ROV; Sedimentation & deposition; Sediments; Software; Tyrrhenian Sea; Italy; Mediterranean Sea; ROV; biogenic habitats; Tyrrhenian Sea; coralline algae; rhodolith beds; maerl
• ISSN: 2223-7747; 2223-7747
• DOI: 10.3390/plants9080985

Rhodolith beds (RBs) are bioconstructions characterized by coralline algae, which provide habitat for several associated species. Mediterranean RBs are usually located in the mesophotic zone (below 40 m), and thus are frequently remote and unexplored. Recently, the importance and vulnerability of these habitats have been recognized by the European Community and more attention has been drawn to their investigation and conservation. This study reports the results of an extensive monitoring program, carried out within the Marine Strategy Framework Directive (2008/56/EC), in six sites off the Campania coast (Italy, Mediterranean Sea). New insights were given into the distribution, cover, vitality (i.e., live/dead rhodolith ratio), structural complexity, and coralline algae composition of RBs. Remotely operated vehicles (ROV) investigations allowed the description of several RBs, and the discovery of a RB with rhodolith cover >65% offshore the Capri Island. Only two sites (Secchitiello and Punta Campanella) showed a very low mean cover of live rhodoliths (<10%); hence, not being classifiable as RBs. The collected rhodoliths were mostly small pralines (~2 cm), spheroidal to ellipsoidal, with growth-forms ranging from encrusting/warty to fruticose/lumpy. Coralline algae identification revealed a high diversity within each bed, with a total of 13 identified taxa. The genus
dominated all sites, and
and
, protected by the Habitats Directive (92/43/EEC), were detected in all RBs.