This dataset includes data of plastic litter collected by citizens and students during 12 campaigns that were organised in Crete (Greece) during the period May 2022 – May 2023. The campaigns were organized within the framework of the NAUTILOS Horizon 2020 project. More specifically the number of plastic litter items per category (using the J code List of the EMODnet Chemistry Thematic Lot n°4) was recorded together with information about the location, date, surface area covered, data contributor and some environmental characteristics (sediment, weather, surroundings).

The dataset includes time-series of Posidonia oceanica production over ~20 years (1997 -2018) at sixty sites in the Greek Seas. The dataset also include environmental variables for the same sites and time -period (i.e., sea surface temperature, sea surface temperature of August, Chlorophyll a, Suspended particulate matter, Secchi depth)

This dataset gather isotopic ratios measured on 359 fish, sharks and crustaceans collected between 200 and 800 m depth, in the Mediterranean canyons during MEDITS 2012 and 2013 surveys Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

These data were collected during the period of 27/11/2020 and 18/11/2022 from the Heraklion Coastal Buoy station North of Crete. The dataset is comprised of samples collected and analysed under specific dates from this station while being part of the European project: "JERICO S3 (Joint European Research Infrastructure of Coastal Observatories: Science, Service, Sustainability)".

The Universidad del Caribe responds to the demand for technical support for the elaboration of specific bathymetric charts for a polygon of 458 Ha that is located between the Isla Contoy National Park and Cayo Alcatraz. The objective was to make a bathymetric map of the polygon and point out the main characteristics or morphological features. Likewise, CTD cast were carried out to have a database with future application to mariculture, with the purpose of contributing to the economic development of communities in Quintana Roo through economic diversification and regional cultural identity and promoting fair trade and solidarity that favor the production and consumption of original products.This activities of the Node for the Promotion of the Social and Solidarity Economy (NODESS) called Selva, Mar y Comunidad Pre Registration Folio SINCA_PNSS_20_00009_INAES, made up of the Universidad del Caribe, Directorate of Economic Promotion of the H. Ayuntamiento of Lázaro Cárdenas, Muuch Kaab Cooperative, Cooperative University of Community Innovation, Mar de las Antillas Cooperative and Tianguis del Mayab. This technical report is at the request of the Cooperativa Mar de las Antillas. Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

CTD measurements as a part of observation plan in the coastal area near Mersrags were performed within the project "AQUAFIMA – Integrating Aquaculture and Fisheries Management towards a sustainable regional development in the Baltic Sea Region". Observations were made at a potential fish spawning and nursing site in the coastal area of the Gulf of Riga in August 2013.

Coastal marine sediments receive intensive stress from urbanization and industrialization, which is manifested by increased contents of heavy metals and organic pollutants. Saronikos Gulf and the small embayment of Elefsis, stretch along the coast of the greater Athens and Pireaus port, the most urbanized and industrialized areas in Greece. Here we present the data of a 20-years geochemical record on grain-size, organic carbon, and major and trace elements contents of the Saronikos Gulf sediments. A total of 216 sediment samples were collected within the period of 1999 to 2018 from the four sub-sectors of the gulf, namely, the Elefsis Bay, the Inner, Outer, and Western (Megara and Epidavros basin) Saronikos Gulf. Additionally, at least one core was obtained from each sub-sector. Sediments deposited at pre-industrial periods were recognized by 14C and 210Pb datings, and served for establishing regionalized, background levels of metals. Factor analysis was conducted to reveal the inter-parametric relationships, thus their common sources, as well as transport and deposition pathways. Then, Enrichment Factors and the multi-elemental Modified Pollution Index (MPI) were calculated to assess the current environmental status of the sediments. Data of sampling sites with at least a five-year record, were assessed for temporal trends, to explore whether sustained, increasing or decreasing trends of the MPI are observed. The dataset and analyses presented here support the research article entitled Geochemistry of major and trace elements in surface sediments of the Saronikos Gulf (Greece): assessment of contamination between 1999 and 2018 by Karageorgis A.P., Botsou F., Kaberi H., and Iliakis S., https://doi.org/10.1016/j.scitotenv.2020.137046

The investigations of Blekinge coast started in 1978. In 1990 the program "Blekinge Kustvattenkontrollprogram" Blekinge Coastal water control programme, was formed, building on the stations sampled earlier, but with extended sampling.

Narrative: The mapping of the landslides have been carried out base on multibeam bathymetry recorded using Simrad EM12 and Atlas HYDROSWEEP DS multibeam echosounders, during cruises from the Spanish Fishing General Secretary (2003 and 2004) and FAUCES (2018) Project. Morphometric attributes such as slope gradients, profile curvatures, planar curvatures and roughness were obtained by ArcMap (GIS), and topographic profiles allowed us to obtain a better characterization of landslides. Also seismic records with different degrees of penetration (0.5 to 1.5 s) and resolution (from a few metres to decimetres) were analysed for landslide characterization. Publication:Ercilla, G., Galindo-Zaldívar, J., Estrada, F., Valencia, J., Juan, C., Casas, D., ... & Yenes, M. (2022). Understanding the complex geomorphology of a deep sea area affected by continental tectonic indentation: The case of the Gulf of Vera (Western Mediterranean). Geomorphology, 402, 108126.

Coral reefs are one of the most diverse ecosystems on Earth. They are currently exposed to increasing levels of anthropogenic perturbations. Several recent reviews point to the lack of good indicators for these perturbations especially to monitor their effects on fish populations or fish assemblages. The SW lagoon of New Caledonia is an ideal location to test indicator species in this context as contrasting sites are present within a small geographical range. This study analysed fish from four sites, one with heavy industrial pollution, another dominated by domestic waste, a third with historic mining activities, and the fourth as a control. The butterfly fish, Chaetodon speculum, was chosen to determine C. speculum’s potential as an indicator species due to its link to coral, its sedentary behaviour and its wide geographical distribution. The size distribution, growth rate, age distribution and whole otolith composition were analysed at each site. Age and mean growth rate were analysed from daily increments of the otoliths. The concentrations of eight elements (Li, Mg, Co, Cu, Rb, Sr, and Ba) were measured by ICP-MS in the otoliths. The sites under anthropogenic impact were distinct from the control site by fish size frequencies, age distributions, and the chemical content of their otoliths. The chemical elements Mg, Co, Cu, and Rb showed differences amongst sites. Fish belonging to the sites furthest from Noume´a could be discriminated in nearly 80% of samples or 60% of the cases when otolith weight or fish age respectively were taken into account. Ni concentrations of the otoliths were also higher in the bays where water concentrations of this element were known to be higher, but these differences were no longer significant once corrected for otolith weight. Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.