Abundance data (individuals.100 m-3) of planktonic cnidarians collected during the Camadas Finas III oceanographic cruise along the North Brazilian continental shelf between the Amazon and Oyapok river mouths and equatorial Atlantic oceanic waters between 8°N, 51°W and 3.5°S, 37°W. Data was obtained during the oceanographic cruise Camadas Finas III, aboard the research vessel NHo. Cruzeiro do Sul - H38 (DHN/Brazilian Navy), performed in 9-31 October 2012. Planktonic cnidarians were sorted from zooplankton samples collected at at 44 stations in oblique hauls, using Bongo nets with 120 and 300 µm mesh and 0.3 and 0.6 m mouth diameter, respectively. The water column was sampled from near the bottom to the surface over the continental shelf and from 200 m to the surface in the offshore. The net was towed at approximately 2 knots, at various times of day and night. 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.

Geological features of seabed habitats extracted from an extant layer of the official cartography of the MPA

Pressure, temperature, conductivity, and derived salinity data with their associated quality flags from the Vigo section of the monitoring program "Oceanography Time Series in Northern Spain" (RADIALES; https://www.seriestemporales-ieo.net/), carried out by the Instituto Español de Oceanografía. Data were collected biweekly to monthly from August 1987 to September 2020 in the interior of the Ría de Vigo and its adjacent shelf, at four stations with depths ranging from 29 m to 148 m. Data were acquired using MARK III, Sea-Bird Scientific 19 SeaCAT, SBE 9 Plus and SBE 25 Sealogger CTD (conductivity, temperature, depth) profilers. They were processed using Sea-Bird Scientific's Seasoft software package, and subsequently, quality controlled with both ctdcheck (https://github.com/PabloOtero/CTDChecker) and Ocean Data View software.  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.

The data concerns the structure and morphometry of the seagrasses Zostera marina and Zostera noltei, the diversity of the associated epifauna and the benthic fluxes of oxygen, carbon and nutrients. The dataset includes 103 sampling events divided among four sites and spread across three distinct marine biogeographic regions (i.e. the English Channel, Bay of Biscay and Western Mediterranean), and up to five seasons, depending on the site. The sampling scale allows inter-site and intra-habitat comparisons . Environmental conditions are also described at the site scale. As the most comprehensive and broadscale French dataset on seagrass structure and functioning  to date, it is useful for both data analysis and management actions. 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.

Since its establishment in 2010, the Mayotte Marine Natural Park has been promoting fishing activities beyond the lagoon, specifically targeting pelagic species to alleviate fishing pressure on reef species. However, despite these efforts, catches of reef fish remain notably high. In 2020, reef carnivores (groupers, snappers…), constituted approximately 35% of the total catches. Ensuring the sustainability of reef fishing necessitates regular assessments of Mayotte's commercial reef fish populations. This study aims to evaluate the current status of these populations and comprehend their dynamics by comparing them with historical data. Scuba diving was employed for the assessment of ichthyological populations and habitat description. In 2023, a total of 96 sites, comprising 1,100 stations (Stationary visual census), were sampled, covering a combined sampled area of 169,400 m2, with an in situ observation duration totalling 110 hours. 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.

During the late spring and summer of 2020, the SLU Aqua Sailor drone sails between the great Swedish islands of Öland and Gotland and collects data on the amount of fish and zooplankton. The drone survey partly takes place at the same time as the fisheries survey Sprat Acoustic Survey (Spras). Spras collects information on herring and sprat in the Baltic Sea, and is carried out with the research vessel R/V Svea. By matching data from Spras with data from the sailing drone, the researchers hope to gain better knowledge of how the Baltic Sea ecosystem works. This was repeated in 2022-2023. In 2019, SLU Aqua Sailor was used around the islands Karlsöarna in the Baltic Sea during 42 days between April and July 2019. The same survey took place In 2020 and 2021

All major businesses that have a discharge point into water and according to the Environmental Code are classified as environmentally hazardous are also responsible for taking samples of the water they discharge themselves. Such a business can, for example, be an industry, a sewage treatment plant or a large farm. Since the water that a discharge point empties into is called a recipient, this sampling is called recipient control. The municipality conducts water quality sampling at all discharge points from the treatment plants. Through this sampling, we measure, among other things, depth of view, oxygen content, levels of nutrients and more. The purpose of the investigation is to describe and monitor the environmental impact on the recipient from Osthamar's treatment plant and urban area.

The methodology used for monitoring has been applied in the Baltic Sea Region since 2011 and is based on the recommendations issued by UNEP/IOC in 2009. It has been further developed, considering the guidelines of HELCOM, OSPAR, and recommendations of the European Commission's JRC Marine Litter working group. Marine beach litter monitoring data were gathered from 15 beaches. Monitoring of 13 sites was conducted three times during the spring, summer, and autumn periods, while two beaches were visited once (in the spring) and then replaced with other beaches (no further marine litter monitoring was carried out at these sites in 2023).

Alien species from a field observation

This dataset assembles historical information existing in public and private documentary archives. Taken together, these data contribute to the building of a knowledge base of the historical presence, extent and biogenic formations of European flat oyster ecosystems prior to and during the intensification of bottom fishing activities. To identify and recover such information requires significant resources and expertise. The establishment of a Historical Ecology Working Group under the umbrella of the Native Oyster Restoration Alliance in early 2020 presented a unique opportunity to coalesce interdisciplinary expertise and resources from multiple European countries to collate and interrogate historical data sources. To date, this is the only known dataset that evidences the past distribution, extent and characteristics of this seabed ecosystem across its full biogeographic range. The described datasets present qualitative and quantitative extracts from written records published between 1524-2022, which show: (1) estimated locations of past oyster fisheries and/or reef habitat across its full biogeographical range, with associated levels of confidence; (2) recorded extent of past reef habitats, and; (3) species associated with these habitats. This comprehensive historical analysis demonstrates that oyster reefs were once a dominant three-dimensional feature along much of the European coastline and some shallow shelf seas.