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Biodiversity of the upper-mesophotic octocoral habitats at Sporades Archipelago (Aegean Sea)
Giovanni Chimienti, Michela Maiorca, Markos Digenis, Dimitris Poursanidis. Conservation status of upper-mesophotic octocoral habitats at Sporades Archipelago (Aegean Sea), 2023.
Contact: Poursanidis, Dimitris ;

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Archived data
Availability: Creative Commons License This dataset is licensed under a Creative Commons Attribution 4.0 International License.


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.


Project Data
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

Title    “The Coral gardens of Alonnisos Northern Sporades Marine Park”
Funding    Funded by the Thalassa Foundation.
Study Area Description    Alonnisos Northern Sporades Marine Park

Sampling Methods
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.

Study Extent    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.
Quality Control    Taxonomic Data mapped to WoRMS.
Method step description:

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.

Biology > Benthos
Marine/Coastal, Octocorals, MED, Aegean, Anthozoa, Ascidiacea, Asteroidea, Demospongiae, Holothuroidea, Polychaeta, Teleostei

Geographical coverage
MED, Aegean [Marine Regions]

Temporal coverage

Taxonomic coverage
Anthozoa [WoRMS]
Ascidiacea [WoRMS]
Asteroidea [WoRMS]
Demospongiae [WoRMS]
Holothuroidea [WoRMS]
Polychaeta [WoRMS]
Teleostei [WoRMS]

Foundation for Research and Technology - Hellas (FORTH)data creator
Poursanidis, Dimitris
University of Bari Aldo Morodata creator
Chimienti, Giovanni
Maiorca, Michela
Ionian Universitydata manager
Digenis, Markos

Related datasets
Published in:
EurOBIS: European Ocean Biodiversity Information System, more

Dataset status: Completed
Data type: Data
Data origin: Research: field survey
Metadatarecord created: 2024-02-07
Information last updated: 2024-04-10
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