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We present a compilation and analysis of 1099 Holocene relative shore-level (RSL) indicators including 867 relative sea-level data points and 232 data points from the Ancylus Lake and the following transitional phase from 10.7 to 8.5 ka BP located around the Baltic Sea. The spatial distribution covers the Baltic Sea and near-coastal areas fairly well, but some gaps remain mainly in Sweden. RSL data follow the standardized HOLSEA format and, thus, are ready for spatially comprehensive applications in, e.g., glacial isostatic adjustment (GIA) modelling. Sampling method The data set is a compilation of rather different samples from geological, geomorphological and archaeological studies. Most of the data was already published in different formats. In this compilation we homogenized the meta information of the available information according to the HOLSEA database format, https://www.holsea.org/archive-your-data, which is a modification of the recommendations given in Hijma et al. (2015). In addition to the reformatting, the majority of samples with radiocarbon dating were recalibrated with oxcal-software using the calib13 and marine13 curves. Furthermore, all sample descriptions were critically checked for consistency in positioning, levelling and indicative meaning by experts of the respective geographic region see Supplement 2. Analytical method In principle, it is a compilation, recalibration and revision of already published data. Data Processing Data of individual compilations were revised and imported into a relational database system. Therein, the data was transferred into the HOLSEA format by specified rules. By this procedure, a homogeneous categorisation was achieved without losing the original data. Also this is stored in the relational database system allowing for later updates of the transfer procedure or a recalibration of the data. Description of data table HOLSEA-baltic-yymmdd.xlsx The workbook in excel format contains 5 sheets, see https://www.holsea.org/archive-your-data: · Long-form, containing the complete information available for each sample · Short-form, a subset of attributes of the Long-form sheet · Radiocarbon, containing the radiocarbon dating information of the respective samples · U-series, a corresponding table containing the respective information of Uranium dating · References, a complete reference list of the primary publications in which the individual data sampling is described. All online sources for the compilation are included in the metadata. A full list of source references is provided in the data description file.

© The authors 2017. Intertidal areas are considered to be productive habitats, but due to the challenging and dynamic environment, in situ assessments of their performance remain scarce. Here, we aimed to quantify the production and turnover of organic material in an intertidal sediment across several consecutive diel/tidal cycles and to evaluate the importance of key drivers affecting the community performance. Time-series measurements of the oxygen (O2) microdistribution across 2 sites at a silty sandflat documented extreme variability, which was mainly driven by light availability and flow conditions. Diffusion dominated the interstitial solute transport, but advective porewater transport was observed during 15% of the 9 d study period. Photosynthetic activity never exhibited light inhibition and average daytime net photosynthesis ranged between 1.01 and 11.15 mmol m-2 d-1 depending on the daily light availability, while the assessed gross primary production was ∼80% higher. When irradiance exceeded 17.2 mol photons m-2 d-1, daytime net autotrophy more than balanced the heterotrophic activity during the night (average night-time respiration, ERn: -4.01 mmol m-2 d-1). However, despite intense primary production, the integrated activity during the target autumn period was net heterotrophic with an average net ecosystem metabolism of -2.21 (span: -7.93 to 1.48) mmol O2 m-2 d-1. This study highlights the extreme temporal and spatial variation of intertidal sediments and the importance of accounting for natural in situ dynamics to correctly assess their performance and contribution to system production.

The island of Samsø is located in the southern Kattegat region of Denmark, a relatively sheltered micro-tidal environment. The area experienced a period of rapid transgression during the early Altantic period, reaching its maximum approx. 7,600 yr BP. Since then, isostatic uplift gradually caused relative sea-level to drop. Originally, two Pleistocene elevations existed as separated islands, which were high enough to reach above sea-level during the transgressions. Proceeding coastal erosion produced material that was transported longshore and that was successively accommodated in a shallow sound. Over time, an extensive beach ridge system formed, which eventually connected the islands, giving Samsø its characteristic shape.Ephemeral shallow-water lagoons evolved in topographic depressions along the shores of the island, most of which became inactive until today. A semi-enclosed coastal lagoon remained in the NE part of the island, which developed around an archipelago of submerged moraine hills.In the scope of this project we will study the evolution of the coastal landscape from the mid-Holocene to present day. We use a multi-proxy approach to resolve local variations in sea-level and to investigate associated geomorphic responses in coastal lagoon and beach ridge systems. Vibracorings will be carried out in these sedimentary environments and will be supplemented with manual auger corings and ground penetrating radar (GPR) surveys to assess vertical variations in the deposited sediments. The aim is to facilitate a three dimensional interpretation of processes, rates, and dynamics of coastal lagoons and associated systems. Recent foraminiferal assemblages will be employed to support facies description and interpretation of collected sediment cores. The use of benthic foraminifera for the reconstruction of Holocene sea-level variations is a novel approach in the Kattegat region.We present preliminary results obtained during fieldwork in spring and summer 2012.

Gross sedimentation rates (GSR) were measured using sediment traps placed at different levels above die seabed (0.3, 0.5, 0.8, 1.0, 2.0, 4.0, 6.0, 8.0, 10.0 m) at a water depth of 17 m. The traps were deployed for 1.25 year. The study was carried out at a location in die semi-enclosed Aarhus Bay, in the southwestern part of the Kattegat, which forms the transitional zone between the highly saline (32-34) North Sea and the less saline (15-20) Baltic Sea. Hydrographic conditions in the Aarhus Bay are dominated by significant changes in salinity during the year, and the water column was stratified for 80 % of the time. High GSR values were recorded near the seabed with a mean of 114.8 (g m-2 day-1) at 0.3 m above the seabed, whereas low GSR values were recorded in the upper traps with a mean of 5.5 (g m-2 day-1) at 10 m above the seabed. The density difference between surface and bottom water was used as a stratification parameter. A strong negative correlation between stratification and wind energy transfer was found. The negative correlation was due to opposite seasonal components of in- and outflow of waters increasing the density difference, i.e. in- and outflow occurred predominantly in seasons with calm wind conditions. Correlation coefficients were high and positive between wind energy and GSR 6.0 m above the seabed due to enhanced turbulent diffusion of suspended particulate matter in periods of strong winds. Resuspension of bottom sediments by surface waves also occurred, increasing GSR at all trap levels. A net sedimentation rate given by the Pb-210 method (2.5 g m-2 day-1) was low compared to the high GSR near the seabed (114.8 g m-2 day-1), this difference being primarily due to resuspension by currents and waves.

9 pages, The increase in exploitation and use of the aquatic environment by humans with increasing population enhances the need for knowledge for future sustainable management of lakes, coastal zones and the open ocean. A frequently used tool for process understanding and management are mathematical models that simulate global, regional and local scenarios. To be reliable models have to be calibrated and validated with high-quality field measurements. The more good data that is used the better the model becomes and forecasting possibilities