Descripción
This dataset contains sessile benthic coverage data derived from photographic quadrat samples collected in two time periods (2008–2009 and 2024) at two coastal sites in Northern Crete: Alykes (Heraklion) and Elounda Bay (Agios Nikolaos). Sampling was conducted along two transects per site at five depths (1 m, 5 m, 10 m, 15 m, and 20 m), using two quadrat sizes (25×25 cm and 100×100 cm) to capture replicate images. The data offer valuable insights into temporal shifts in sessile organism communities, highlighting changes potentially linked to climate change and the increasing presence of invasive herbivorous fish species, such as siganid fish and diademid sea urchins.
Registros
Los datos en este recurso de evento de muestreo han sido publicados como Archivo Darwin Core(DwC-A), el cual es un formato estándar para compartir datos de biodiversidad como un conjunto de una o más tablas de datos. La tabla de datos del core contiene 587 registros.
también existen 2 tablas de datos de extensiones. Un registro en una extensión provee información adicional sobre un registro en el core. El número de registros en cada tabla de datos de la extensión se ilustra a continuación.
Este IPT archiva los datos y, por lo tanto, sirve como repositorio de datos. Los datos y los metadatos del recurso están disponibles para su descarga en la sección descargas. La tabla versiones enumera otras versiones del recurso que se han puesto a disposición del público y permite seguir los cambios realizados en el recurso a lo largo del tiempo.
Versiones
La siguiente tabla muestra sólo las versiones publicadas del recurso que son de acceso público.
¿Cómo referenciar?
Los usuarios deben citar este trabajo de la siguiente manera:
Rallis I, Chatzigeorgiou G, Skouradakis G, Vernadou E, Polychroni T, Pavlidis D, Papagiannopoulos G, Dailianis T (2025). Sessile Benthic Assemblages in Northern Crete assessed from Photographic Quadrats (2008–2024). Institute of Marine Biology, Biotechnology and Aquaculture - Hellenic Centre for Marine Research, Greece. Dataset.
Derechos
Los usuarios deben respetar los siguientes derechos de uso:
El publicador y propietario de los derechos de este trabajo es Hellenic Center for Marine Research. Esta obra está bajo una licencia Creative Commons de Atribución/Reconocimiento (CC-BY 4.0).
Registro GBIF
Este recurso no ha sido registrado en GBIF
Palabras clave
Sessile; Epibenthic; Benthos; Reefs; Samplingevent; Eastern Mediterranean; Aegean Sea; Biodiversity Shifts; Sublittoral; Hard Substrate
Contactos
- Custodio De Los Datos
- Proveedor De Los Metadatos ●
- Punto De Contacto
- Custodio De Los Datos
- Custodio De Los Datos
https://orcid.org/https://orcid.org/0000-0001-6775-530X
- Custodio De Los Datos
Cobertura geográfica
Two areas in Northern Crete, Alykes and Elounda
| Coordenadas límite | Latitud Mínima Longitud Mínima [35,25, 24,97], Latitud Máxima Longitud Máxima [35,42, 25,76] |
|---|
Cobertura taxonómica
Functional Groups: Bivalvia, Erect Chlorophyta, Massive Sponge, Hexacorallia, Mobile Fauna, Mucilage-forming Microalga, Barnacles, Boring Sponges, Massive Chlorophyta, Massive Phaeophyceae, Canopy, Colonial Ascidian, Calcareous Erect Algae, Erect Rhodophyta, Encrusting Sponge, Solitary Ascidian, Encrusting Rhodophyta, Erect Bryozoa, Padina pavonica, Encrusting Chlorophyta, Encrusting Bryozoa, Encrusting Habitat-forming Rhodophyta, Tube-forming Polychaeta
| Filo | Porifera (Sponges), Mollusca (Mollusks), Chlorophyta (Green algae), Rhodophyta (Red algae), Ochrophyta (Brown algae), Cnidaria |
|---|---|
| Class | Ascidiacea (Sea squirts), Polychaeta (Scale worms) |
| Subclase | Cirripedia (Barnacles) |
Cobertura temporal
| Fecha Inicial / Fecha Final | 2008-06-01 / 2024-06-30 |
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Datos del proyecto
MARine Biodiversity and Ecosystem Functioning leading to Ecosystem Services MARBEFES project has received funding from the European Union’s Horizon Europe research and innovation programme under Grant Agreement no 101060937
| Título | MARBEFES |
|---|---|
| Identificador | https://marbefes.eu/ |
| Fuentes de Financiación | This Project has received funding from the European Union’s Horizon Europe research and innovation programme under grant agreement no 101060937 |
| Descripción del área de estudio | The MARBEFES project is structured around the concept that biodiversity is a continuous and interconnected system across space and time, beyond traditional boundaries like ‘estuary,’ ‘coast,’ and ‘offshore.’ This approach helps to avoid compartmentalized thinking that might limit our understanding of marine ecosystems. MARBEFES explicitly considers the river-to-ocean gradient, utilizing 12 Broad Belt Transects (BBTs) across the four main marine regions of the EU – the Arctic, Baltic, Atlantic, and Mediterranean. These transects serve as the core of MARBEFES research, providing data to understand biodiversity trends and their impacts across Europe. |
Métodos de muestreo
Sampling was conducted through non-destructive underwater photographic surveys of fixed-area quadrats. Two permanent transects were established in each study area (Alykes and Elounda) and sampled at five depths (1, 5, 10, 15, and 20 meters) during spring seasons of 2008, 2009, and 2024. At each depth, five photographic quadrats (either 25×25 cm or 100×100 cm) were positioned along the transects on hard substrates. Each image was later analysed using a stratified point count method with 100 randomly distributed points per photo to estimate the percent cover of sessile macrobenthic taxa.
| Área de Estudio | The study was conducted in northern Crete, specifically in the coastal areas of Alykes and Elounda. Sampling took place during the spring seasons of 2008, 2009, and 2024, with two transects surveyed per site each year across five depth zones (1, 5, 10, 15, and 20 meters). The study focuses on hard substrate habitats and is representative of typical rocky reef environments in the eastern Mediterranean. |
|---|---|
| Control de Calidad | Quality control began with structuring the data into a tidy format and applying Darwin Core standards. Taxonomic names were validated via the WoRMS Taxon Match Tool, which uses exact and fuzzy matching to assign AphiaIDs, authorities, and classification metadata. Geographic coordinates were visually inspected using the OBIS Map Tool, generating WKT geometries and calculating centroids and uncertainty radii to confirm sampling locations in marine zones and identify outliers. The dataset then underwent comprehensive QC using the LifeWatch/EMODnet Biology Biocheck tool, which assesses schema compliance, taxonomy, spatial consistency, occurrence and measurement records against EMODnet standards. Finally, metadata were created and published via the MedOBIS IPT, facilitating dataset exposure to OBIS/GBIF and enabling harvesting by international repositories. |
Descripción de la metodología paso a paso:
- Photographic sampling was conducted during spring surveys in 2008, 2009, and 2024 at two coastal locations in northern Crete (Alykes and Elounda). At each site, two transects were established and surveyed at five fixed depths (1, 5, 10, 15, and 20 meters). Photoquadrats (25×25 cm or 100×100 cm) were positioned on hard substrates and photographed using underwater digital cameras equipped with scale frames. Images were later analysed using the stratified random point count method (100 points per quadrat), following established benthic assessment protocols. Data were digitised into a tidy format and standardised using Darwin Core terminology. Taxonomic names were matched to authoritative AphiaIDs using the WoRMS Taxon Match Tool. Coordinates were validated using the OBIS Maptool. Quality control was performed using the LifeWatch/EMODnet Biology RShiny tool, and final metadata were prepared and published via the MedOBIS IPT following OBIS data publishing standards.
Metadatos adicionales
| Identificadores alternativos | 10.25607/meaq9b |
|---|---|
| https://ipt.medobis.eu/resource?r=sessile-benthos-alykes-elounda-2008-2024 |