Beach Litter count data collected across 10 beaches of the Belgian coast in 2023 and 2024 by volunteers of the citizen science association Proper Strand Lopers. One of the key indicators of abundance, composition and trends of litter in the marine environment is the amount on beaches. OSPAR monitors litter on 100m stretches at over 70 beaches in the North-East Atlantic following common monitoring guidelines. The monitoring records litter in 112 predefined litter items in 11 types: Plastic / polystyrene, Metal, Paper and cardboard, Wood, Sanitary waste, Cloth, Rubber, Glass, Pottery/ceramics, Medical waste and Faeces.

UNDER EMBARGO - This dataset originates from the BE/2023 sampling campaign conducted in southwest Greenland fjords (Igaliku and Tunulliarfik) and quantifies grazing impacts by micro- and mesozooplankton on phytoplankton and heterotrophic microbial communities (including bacteria) in two fjord systems characterized by contrasting glacial regimes. Grazing and microbial growth rates were estimated using two-point dilution experiments (two-point dilution experiments), alongside experiments assessing mesozooplankton and copepod grazing on both phytoplankton and microzooplankton. Community responses were resolved using imaging flow cytometry, enabling the identification of plankton functional groups (autotrophic, mixotrophic, and heterotrophic) and size classes. The dataset also includes measurements of chlorophyll a variability determined by high-performance liquid chromatography. Overall, the dataset supports analyses of trophic interactions and grazing dynamics across the microbial food web under differing glacier-influenced environmental conditions.

UNDER EMBARGO - This dataset is part of BE/2023 sampling campagn in SW Greenland fjords (Igaliku and Tunulliarfik) and includes measurements of pelagic community respiration to assess microbial metabolic activity across fjords with contrasting glacial influence and seasonal conditions. Pelagic community respiration rates were determined following Martínez-García et al. (2009): seawater samples (200 mL; n = 4 replicates) were incubated with INT (final concentration 0.8 mM). Control samples were fixed with formaldehyde (2% final concentration) prior to incubation. After incubation, samples were filtered (0.2 μm), and the reduced INT (formazan) retained on filters was extracted with 1-propanol. Formazan concentration was determined spectrophotometrically at 485 nm, subtracting non-metabolic absorbance from controls. INT reduction rates were calculated as μmol INTf L⁻¹ h⁻¹ and subsequently converted to O₂ consumption rates (μmol O₂ L⁻¹ h⁻¹) following Martínez-García et al. (2019).

This dataset is part of the 2024 Belgian submission for the Marine Strategy Framework Directive (MSFD) linked to descriptor 1, criterion 1. It reports the mortality rate of marine mammals, in particular harbour porpoise (Phocoena phocoena), from incidental bycatch in the Belgian part of the North Sea, combining strandings investigations, reported incidental catches and aerial abundance surveys.

This dataset is part of the 2018 Belgian submission for the Marine Strategy Framework Directive (MSFD) linked to descriptor 1, criterion 2. The Raja clavata dataset describes the results of the Offshore Beam Trawl Surveys (BTS) in the Belgian part of the North Sea (BPNS) between 2010 and 2017. Occurrences of Raja Clavata, along with dates and locations, are reported. The codes used in the attached file are based on the ICES DATRAS (Database of Trawl Surveys) standard. The seabirds dataset describes the density of seabirds (N birds/km) observed in the BPNS between 1987 and 2016 (three surveys a year).

UNDER EMBARGO - This dataset is part of BE/2023 sampling campagn in SW Greenland fjords (Igaliku and Tunulliarfik). Pelagic community was analysed using Imaging Flow Cytometry (iFCM) with an ImageStream®X Mk II. Cells were grouped into functional size classes—pico-, nano- and microplankton—according to measured cell length. Cells lacking chlorophyll autofluorescence were classified as heterotrophic or chemotrophic organisms, including heterotrophic picoplankton/bacteria (HP; ≤2 µm) and heterotrophic nanoplankton (HN; 2–20 µm). No larger heterotrophs (>20 µm) were visually detected. Autofluorescent cells were considered phototrophic, although this fraction may also include mixotrophic taxa, and comprised picophytoplankton (AP; ≤2 µm), nanophytoplankton (AN; 2–20 µm), and microphytoplankton (AMicro; 20–100 µm). To estimate the biovolume of each plankton class, the two-dimensional cell surface area measured by the IDEAS® imaging software was multiplied by the mean cell width, assuming that cell width approximates the third spatial dimension. Carbon biomass was subsequently derived from biovolume using established carbon–volume relationships. For the HP fraction, carbon content was estimated using the bacterial conversion proposed by Romanova and Sazhin (2010), where volume is expressed in µm³. Although the HP fraction may also include heterotrophic picoeukaryotes, and its biomass may therefore be partly underestimated, this conversion was applied because the fraction was assumed to be numerically dominated by bacteria. For the other protist groups, carbon biomass was derived following Menden-Deuer and Lessard (2000). Carbon values were converted from pg C cell⁻¹ to carbon biomass (µg C L⁻¹) based on cell abundance.

UNDER EMBARGO - This dataset is part of BE/2023 sampling campagn in SW Greenland fjords (Igaliku and Tunulliarfik). Samples for DNA extraction were collected along fjord transects at several depths of the water column. The focus of the study was to determine the taxonomical composotion of bacterial community in two Arctic fjords.

This dataset contains marine organic matter source samples, artificial mixtures of known composition, and compound-specific nitrogen stable isotope data of amino acids (δ¹⁵N-AA). Source materials include phytoplankton, zooplankton, and faecal pellets from the marine fouling species Mytilus edulis and Metridium senile. Samples were collected and processed in the laboratory under controlled conditions. Artificial mixtures were prepared by combining source materials in defined proportions to generate experimental samples representing multiple marine organic matter source combinations. Metadata describing sample collection, preparation, and mixture composition are included. Compound-specific nitrogen isotope ratios of individual amino acids were measured using stable isotope analysis. The dataset includes isotopic measurements for all source samples and artificial mixtures, along with associated metadata required to document sampling, laboratory preparation, and analytical procedures.

This dataset is part of the 2018 Belgian submission for the Marine Strategy Framework Directive (MSFD) linked to descriptor 10, criterion 1. The seafloor dataset describes the litter gathered between 2012 and 2014 during beam trawl (BTS) fishery surveys in the Belgian part of the North Sea (BPNS). It provides the date, location and haul information, type of litter found and information in the size of the items. Additionally the ship name and cruise references are reported. The data is recorded following ICES guidelines allowing future inclusion in the ICES online database DATRAS (Database of Trawl Survery). The sludge dataset describes the litter found between 2013 and 2016 on dredge disposal sites located in the coastal area of the Belgian part of the North Sea (BPNS). It provides the date, location, amount and type of litter as well as methodological information (e.g. mesh size). Additionally, the ship name and cruise references are reported. The beach litter dataset contains information on beach litter for the period 2012-2016 washed ashore on two reference beaches (Oostende Halve Maan & Oostende Raversijde). 40 surveys (100m transects) have been executed until January 2017. Monitoring & data recording has been done according to the OSPAR Guideline for Monitoring Marine Litter on the beaches in the OSPAR maritime area (OSPAR, 2010). Besides the number of litter items, the category is also noted. The dataset is characterized by a high variation in the number of items. The data are reported to OSPAR beach litter database. Conclusions: see https://odnature.naturalsciences.be/msfd/nl/assessments/2018/page-d10

This dataset is part of the 2018 Belgian submission for the Marine Strategy Framework Directive (MSFD) linked to descriptor 8, criterion 2. This dataset contains measurements on the 7-Ethoxyresorufin-O-deethylase (EROD) activity in Limanda limanda, Imposex (OTIN in Mytilus edulis), fish diseases and counts of oiled common guillemots in the Belgian part of the North Sea.