Research Article

Climate-driven habitat shifts of the vulnerable sea pen Funiculina quadrangularis in the Mediterranean Sea

¹ MARBEC, University of Montpellier, CNRS, Ifremer, IRD, Sète, France
² Institute for Marine Biological Resources and Biotechnology of the National Research Council (IRBIM CNR), Mazara del Vallo, Italy
³ Italian Institute for Environmental Protection and Research (ISPRA), Palermo, Italy
⁴ Hellenic Centre for Marine Research, Institute of Marine Biological Resources and Inland Waters, Greece
⁵ Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas (ICM-CSIC), Passeig Marítim de la Barceloneta 37-49, 16 08003 Barcelona, Spain
⁶ Fisheries Research Institute (INALE), Hellenic Agricultural Organization - DIMITRA (ELGO - DIMITRA), Nea Peramos, Kavala 18 64007, Greece
⁷ Department of Environment, Faculty of Environment, Ionian University, Zakynthos, Greece
⁸ Department of Biosciences, Biotechnology and Environment, University of Bari Aldo Moro, Bari, Italy
⁹ National Inter-University Consortium for Marine Sciences (CoNISMa), Rome, Italy
¹⁰ Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche 60131 Ancona, Italy
¹¹ Department of Biology, University of Malta, Msida MSD2080, Malta
¹² Department of Biological, Geological and Environmental Sciences (BiGeA), Laboratory of Marine Biology and Fisheries, University of Bologna, 61032 Fano, Italy
¹³ Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, 45330 Lysekil, Sweden
¹⁴ Ifremer Centre de Méditerranée, Département Océanographie et Dynamique des Ecosystèmes, COAST, 83500 La Seyne-sur-Mer, France
¹⁵ Fondazione COISPA, Bari, Italy
¹⁶ Institute for Marine Biological Resources and Biotechnology of the National Research Council (IRBIM CNR), Messina, Italy
¹⁷ Centre Oceanogràfic de les Balears (COB-IEO), CSIC, Moll de Ponent s/n, 07015 Palma, Illes Balears, Spain
¹⁸ Consorzio per il Centro Interuniversitario di Biologia Marina ed Ecologia Applicata G. Bacci, 57128 Livorno, Italy
¹⁹ Institute of Marine Biology, University of Montenegro, 85330 Kotor, Montenegro
²⁰ Aquatic Resources Malta, Fort San Lucjan, Triq il-Qajjenza, Marsaxlokk BBG1283, Malta
²¹ Department of Fisheries and Marine Research, Nicosia, Cyprus
²² Agricultural University of Tirana, Albania

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 7 May 2025
Accepted: 30 March 2026

Abstract

The tall sea pen Funiculina quadrangularis (Pallas, 1766), a widespread octocoral species found in Mediterranean soft-bottom habitats, is recognized by the Food and Agriculture Organization of the United Nations as a vulnerable marine ecosystem indicator due to its sensitivity to bottom trawling. Adapted to stable environments, its distribution could be affected by the combined impacts of climate change, particularly warming bottom waters, and trawling activities. Records from the Mediterranean International Trawl Survey program and other sources were used in an ensemble species distribution modelling approach to predict current habitat suitability and project potential habitat shifts under the intermediate IPCC climate scenario SSP2–4.5 for 2050 and 2100. Results indicated a widespread distribution across the Mediterranean continental shelf and slope, with the species typically found between 100 and 750 m depth (occasionally as shallow as 20 m) and tolerating temperatures between 12°C and 16°C. By 2050, over 80% of the current habitat was projected to remain suitable. However, only 50% were expected to serve as climate refugia by 2100, likely due to warming bottom waters and increased salinity. Some habitat gains were projected (e.g., Ligurian Sea, Corsican waters, deep Eastern Mediterranean), but uncertainties persist regarding the species’ ability to colonize these new areas. Despite its presence in trawled areas, suggesting a relatively lower fishing pressure sensitivity than other VME taxa, significant habitat shifts were projected under future climate conditions. Therefore, it is essential to prioritize conservation efforts in areas projected to remain suitable over time. The climate refugia identified through this study offer critical guidance for future climate-smart VME management plans, helping to ensure the long-term survival of F. quadrangularis in the Mediterranean Sea.