10.15468/k72gqm http://ipt.medobis.eu/resource?r=uppermesophotic Dimitris Poursanidis Institute of Applied and Computational Mathematics, FORTH Research Scientist / Data Stewardship

Heraklion GREECE

https://www.linkedin.com/in/dimitrispoursanidis/?originalSubdomain=gr Dimitris Poursanidis Institute of Applied and Computational Mathematics, FORTH Research Scientist / Data Stewardship

Heraklion GREECE

https://www.linkedin.com/in/dimitrispoursanidis/?originalSubdomain=gr Giovanni Chimienti Università degli Studi di Bari Aldo Moro PostDoc Position

Bari ITALY

https://www.researchgate.net/profile/Giovanni-Chimienti CONTENT_PROVIDER Michela Maiorca Università degli Studi di Bari Aldo Moro

Bari ITALY

https://www.researchgate.net/profile/Michela_Maiorca CONTENT_PROVIDER Markos Digenis Department of Environment of the Ionian University PhD student

Zakynthos GREECE

https://www.researchgate.net/profile/Markos-Digenis CUSTODIAN_STEWARD 2023-09-05 ENGLISH The dataset describes the megabenthic biodiversity that has been recorded in five locations at the upper mesophotic zone of the National Marine Park of Alonissos Northern Sporades. The expedition ran in the summer of 2021 with a focus on the study of the structure of the octocoral habitats with emphasis on the forests of Eunicella cavolini and Paramuricea clavata. Non-invasive methods have been applied to collect the relevant information. This includes 4K GoPro cameras with lights and scaled laser beams along with an underwater camera system with strobes. The provided dataset is preliminary and far from being considered complete; however, it sets the foundation for new information to be added in future expeditions. Metadata GBIF Dataset Type Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_type.xml Biodiversity none gorgonians none upper-mesophotic none octocoral none Northern Sporades Aegean Sea https://www.marineregions.org/gazetteer.php?p=details&id=3684 This work is licensed under a Creative Commons Attribution (CC-BY) 4.0 License . Creative Commons Attribution 4.0 International https://spdx.org/licenses/CC-BY-4.0.html CC-BY-4.0 http://ipt.medobis.eu/archive.do?r=uppermesophotic National Marine Park of Alonissos Northern Sporades (Aegean Sea, Greece) 22.906 24.532 39.593 39.011 2021-06-20 2021-06-26 Algae, Ascidiacea, Bryozoa, Cnidaria, Crustacea, Echinodermata, Mollusca, Pisces, Polychaeta, Porifera Class Ascidiacea Phylum Bryozoa Phylum Cnidaria Subphylum Crustacea Phylum Echinodermata Phylum Mollusca Superclass Pisces Class Polychaeta Phylum Porifera Algae unkown Dimitris Poursanidis Institute of Applied and Computational Mathematics, FORTH Research Scientist / Data Stewardship

Heraklion GREECE

https://www.linkedin.com/in/dimitrispoursanidis/?originalSubdomain=gr Based on local knowledge and interviews with diving centers, five sites have been selected for the assessment of upper mesophotic coral forests. Three of them are located in the straits of Skopelos–Alonnisos, at Agios Georgios islet and Mikro islet, and at the tip of Fanari in Alonnisos. Two more sites are located 1.5 nautical miles northeast of Dyo Adelfia islet, at the so-called Barketa reef, and off the twin islets Moro and Moules. Octocoral forests created by the yellow sea fan Eunicella cavolini and the red sea fan Paramuricea clavata were studied at the National Marine Park of Alonissos Northern Sporades (Aegean Sea, Greece), between 30 and 45 m depth, in order to assess their conservation status and the occurrence of both natural and anthropogenic stressors. Equipment used are GoPro cameras, Canon Cameras, Visual Census. During June 2021, technical scuba diving operations were carried out at every site to verify the occurrence of coral forests and perform noninvasive monitoring from 30 to 45 m depth, with qualitative explorations up to 60 m depth. Underwater videos were carried out using 4K cameras equipped with two video lights of 12,000 lm each and two parallel laser beams for scaling. Image analysis and processing for the coral forests were performed using ImageJ/Fiji software, and sampling units of 2.5 ± 0.2 m2 were defined along each transect, according to the minimal area used for the quantification of Mediterranean octocoral habitats. Taxonomic Data mapped to WoRMS. Dimitris Poursanidis https://www.linkedin.com/in/dimitrispoursanidis/?originalSubdomain=gr POINT_OF_CONTACT This work is part of the project “The Coral gardens of Alonnisos Northern Sporades Marine Park”, funded by the Thalassa Foundation. Without them, this work could not be possible. Special thanks to the Eforate of Undewater Antiquites for the special permission for Science Dive operations, to Panos Anagnostou and the Alonissos-Seacolours Dive center for the technical support and the Management Body of the Alonnisos Northern Sporades Marine Park for their support Funded by the Thalassa Foundation. Alonnisos Northern Sporades Marine Park 2026-04-14T08:24:20Z Poursanidis D (2023). Biodiversity of the upper-mesophotic octocoral habitats at Sporades Archipelago (Aegean Sea). Hellenic Center for Marine Research. Sampling event dataset https://doi.org/10.15468/k72gqm accessed via GBIF.org on 2026-04-14. Giovanni Chimienti, Michela Maiorca, Markos Digenis, Dimitris Poursanidis, Conservation status of upper-mesophotic octocoral habitats at Sporades Archipelago (Aegean Sea), Marine Pollution Bulletin, Volume 190, 2023, 114868, ISSN 0025-326X, https://doi.org/10.1016/j.marpolbul.2023.114868.