NIOZ Dataverse
Not a member yet
213 research outputs found
Sort by
North Sea plastic films ex-situ incubations - ASVs taxonomy and abundance data
No full textThis dataset comprises the ASV and taxonomy table. The average relative abundances and standard deviations are calculated for each taxonomic rank and each type of sample
Balgzand macrozoobenthos database 1967 - 2019
No full textThe Balgzand macrozoobenthos programme was set up initially to study the secondary production of the macrobenthic invertebrates of the Wadden Sea. This happened within the framework of the International Biological Programme (IBP) (1967), an initiative to study the biological productivity of various ecosystems worldwide.
The programma was initially meant to study the productivity of biomass of larger macrozoobenthic invertebrate in- and epifauna. The focus was on species that easily could be separated into cohorts (year classes). This meant that bivalve molluscs that deposit clear growth marks in their shells had priority. Small items, e.g. small polychaetes, were ignored as contributing very little to the total invertebrate benthic biomass.
To study the annual variability in benthic biomass, a frequent year-around sampling programme on 3 permanent quadrats was developed and started in 1967. These quadrats were selected based on sediment composition and tidal elevation, to cover a variety of sediments within Balgzand. Station Dk was nearshore with sandy mud, around mean tide level, station Sl was relatively near by Dk but closer to a tidal gully, on a sandy sediment and a tidal elevation of ± 10 cm above mean tide level, station Mz was on the northern tip of Balgzand, around mean low tide level with relatively course sand.
On these quadrats, sampled roughly once per month, boxes of ± 0.1 m² were dug out, and additionally round cores of 0.009 m² were taken. Based on the results of these frequent samplings an additional series of 12 transects, scattered over intertidal Balgzand, was chosen to cover the variability of the study area. These 12 transects were sampled twice a year, in late winter to estimate the benthic biomass at the lowest level during the year, and in late summer at the moment of maximal benthic biomass values and to estimate the recruitment of the benthic invertebrates in the previous spring and early summer. The transects were explored first in summer 1968, the results are not incorporated in the database. The results from late winter 1969 onwards are included in the database. From summer 1969 onwards the frequency of sampling of the the 3 permanent quadrats was reduced to 4 times per year, from 1988 onwards to twice per year
High-resolution current meter and hydrographic data from the Irminger Current mooring array 2020 - 2022
No full textThe Irminger Current mooring array consists of 5 subsurface ocean moorings in the Irminger Current on the Reykjanes Ridge in the North Atlantic Ocean. The fifth high-resolution data set of oceanographic variables from instrumentation of these moorings was collected from 26 of July 2020 to 6 August 2022. The moorings are named IC0, IC1, IC2, IC3 and IC4 going from west to east. The Irminger Current mooring array is part of the international Overturning of the Subpolar North Atlantic Program (OSNAP, www.o-snap.org) which runs from 2014 to at least 2024. The data set consists of ocean temperature, salinity, current velocities, pressure and time. Variables were collected at different time intervals, varying from 5 minutes to 1 hour. The data have been calibrated and quality controlled. The data and the metadata are stored in NetCDF files following the Climate Forecast (CF) conventions, see http://cfconventions.or
Temperature-enhanced effects of iron on Southern Ocean phytoplankton - associated data
No full textIron (Fe) is a key limiting nutrient for Southern Ocean phytoplankton. Input of Fe into the Southern Ocean is projected to change due to global warming, yet the combined effects of a concurrent increase in temperature with dissolved Fe (dFe) addition on phytoplankton growth and community composition are understudied. To improve our understanding of how Antarctic phytoplankton communities respond to Fe and enhanced temperature, we performed four full factorial onboard bioassays under trace metal clean conditions with phytoplankton communities from different regions of the Weddell and the Amundsen Seas in the Southern Ocean. Treatments consisted of a combined 2 nM dFe addition with 2 °C warming treatment (TF), compared to the single factor treatments of Fe addition at in-situ temperature (F), and non-Fe addition at + 2 °C (T) and at in-situ temperature (C). Temperature had limited effect by itself but boosted the positive response of the phytoplankton to Fe addition. Photosynthetic efficiency, phytoplankton abundances, and chlorophyll a concentrations typically increased (significantly) with dFe addition (F and/or TF treatments) and the phytoplankton community generally shifted from haptophytes to diatoms upon dFe addition. The < 20 µm phytoplankton fraction displayed population-specific growth responses, resulting in a pronounced shift in community composition and size distribution (mainly towards larger-sized phytoplankton) for the F and TF treatment. Such distinct enhanced impact of dFe supply with warming on Antarctic phytoplankton size, growth and composition will likely affect trophic transfer efficiency and ecosystem structure, with potential significance for the biological carbon pump
Intertidal juvenile crustacea - data
No full textAim: to study the dynamics of juvenile epibenthic crustaceans (Crangon crangon and Carcinus maenas), species that heavily prey upon newly settled bivalve postlarvae and juveniles in the intertidal of the Wadden Sea.
Study area:
At Balgzand, a tidal flat area east of Den Helder, permanent sampled intertidal stations were selected to study densities and size distribution of the two crustacean species. Names and locations of the permanent stations are listed in Table STAT.
Sampling period and frequency:
The stations 1-3 were sampled in the years 1983-2019, the stations 4 and 5 in the years 1998-2019. The focuss of the sampling period each year was in the period May-June, the period of settlement of juveniles of most common bivalve species on the intertidal flats. In a number of years sampling continued in the months July and August, in other years started already in April. The frequency of sampling was at least once per 14 days, often even more frequent.
Sampling set-up:
Each sampling was preferably carried out shortly after the emersion of the sampling station during outgoing tide. At each station at each sampling day 4 samples were taken. Each sample consisted of 10 round cores taken close together (± 1 m) with a surface of 0.009 m² each, sampling depth ± 4 cm. Thus each sample covered 0.09 m², the total surface of the 4 samples per sampling station was 0.36 m². Samples were sieved in the field over a 1-mm square-mesh sieve. Up to and including 2010, the contents of the sieve were stored unpreserved in labelled plastic bags, and after return directly sorted alive in the laboratory. From 2011 onwards the samples were directly preserved in plastic jars in 4% formaldehyde. In the laboratory the preserved samples were stained with Rose-Bengal before sorting.
In the laboratory the samples were sorted with the naked eye in plastic trays. All shrips and crabs were taken out, identified and measured up to the nearest mm. From the shore crabs the carapace width was measured, from the shimps, for practical reasons, the length from the tips of the scaphocerites to the tip of the telson was taken. This in contrast to the normal standardized measurement of a shrimp: from the tip of the rostrum to the tip of the telson
SIBES dataset
No full textHere, we present SIBES-data on median grain size (micrometer) and mud content (%) of sediment, and abundances (#) and biomass (g) of benthic invertebrate found at sampling stations on intertidal mudflats of the Dutch Wadden Sea. SIBES stands for Synoptic Intertidal BEnthic Survey and is a long-term ecological time-series performed by NIOZ. It is aimed at understanding ecological processes and sediment dynamics of intertidal mudflats related to benthic invertebrates. Details of the sampling method, laboratory protocols and data curation can be found in the accompanying paper in the journal "Scientific Data" (https://doi.org/10.1038/s41597-025-04540-9). In summary, roughly 4,500 stations are sampled yearly from 2008 and onwards. The most recent 3 years are under embargo, but available upon request to the corresponding author. Samples were collected on a 500 m grid and on randomly located stations in the months June to October. Stations were not sampled at the same dates across years. Sampling stations were visited by foot during low tide and by boat during high tide. At each site sampled by boat, two cores were taken to a depth of ~25 cm (combined area of 0.0173 m2). Samples were sieved on a 1 mm round mesh in the field. After sieving, large bivalves were separated from the other species and frozen at -20 degrees Celsius to allow for easier process in subsequent laboratory analysis. From the remaining sample, all benthic invertebrates were collected and preserved at a 4% formaldehyde solution. Sediment samples were taken with a small core with a diameter of 33 mm from the surface of the inter-tidal flats to a depth of 4 cm and then frozen at -20 degrees C. In the laboratory, organisms were identified and counted and their biomass determined as ash-free dry-mass (AFDM). Sediment samples were freeze-dried and grain size distributions measured with a particle size analyser. For further details concerning methods, processing, data curation, analyses and R-scripts, we refer to the accompanying paper. When using these data, please cite that paper (https://doi.org/10.1038/s41597-025-04540-9). An R-library with examples of analysing and plotting the data is provided online at https://github.com/allertbijleveld/sibes. In sharing these data, we hope to enhance collaborations and understanding of the impact of various pressures on macrozoobenthic invertebrates, sediment composition, food webs, the ecosystem, and biodiversity in the Wadden Sea and other intertidal habitats
NIOZ jetty hourly data for temperature and salinity for 2023
No full textNIOZ jetty LON=4.789E LAT=53.002N, using EXO sensor at depth of -1.5 meter NAP. Derived product from 10 second calibrated data. Separate calibration measurement at 2 week intervals
NIOZ jetty hourly data for temperature and salinity
No full textGeneral DOI for the NIOZ jetty time series of hourly values of temperature and salinity since 2001.
NIOZ jetty LON=4.789E LAT=53.002N, measurements at -1.5 meter NAP. Derived product from 10 minute calibrated data. Separate calibration measurement at 2 week intervals
Dataset belonging to "Glacial mid-depth carbon storage and the role of Northern African upwelling in the last deglaciation"
No full textUpwelling systems are important components of the carbon cycle due to their role in redistributing CO2 from mid-depth to the ocean surface and thereby affecting sea-atmosphere exchange of CO2. This latter flux is affected by multiple factors, involving oceanography and local climate conditions, that have also contributed to glacial-interglacial variability of atmospheric pCO2. Along the shore of northwestern Africa, the Canary Current Upwelling System (CCUS) brings the nutrient- and CO2-rich Antarctic Intermediate Water (AAIW) to the surface. Today, upwelling intensity in this region is characterized by seasonal fluctuations linked to the migration of the Intertropical Convergence Zone. Due to differences in biology-driven CO2 uptake, ocean-atmosphere interaction in this region differs between the northern and southern cells, featuring net CO2-sink and CO2-source properties, respectively. To better understand glacial-interglacial processes of the North Atlantic tropics, we reconstructed temperature and pCO2 based on both organic (UK ʹ37, δ13C of alkenones) and inorganic proxies (Mg/Ca and δ11B of foraminiferal carbonate). These proxy signal carriers allow constraining conditions both in the surface (using alkenones and T. sacculifer) and subsurface (using G. bulloides). Subsurface carbon contents, upwelling rate and the position of the Cape Verde Frontal Zone (CVFZ) all affect the carbon speciation of the upwelled water. The 120 ka BP records of reconstructed pCO2 suggest that carbon dynamics of the region were very similar to present-day conditions prior to the glacial, between approximately 120 and 75 ka BP. During the Last Glacial, however, ocean circulation and water mass distributions differed substantially from modern conditions. Expansion of the AAIW during the glacial affected upwelling intensity and inorganic carbon chemistry of these upwelled waters. Our records provide evidence for enhanced carbon storage at mid-depth from the early stage of the glacial onwards and they also show that this did not contribute to appreciably local outgassing until approximately 30 ka BP. An efficient biological carbon pump fuelled by enhanced nutrient supply from the upwelled waters as well as micro nutrients from Saharan dust and river runoff, could effectively retain carbon in this region. A reduction in local nutrient sources during the later phases of the Last Glacial eventually resulted in the release of carbon stored at mid depth of the CCUS and hence, potentially contribute to the onset of the last deglaciation
Co-occurring intertidal ecosystem engineers with opposing growth strategies show opposite responses to environmental gradients during establishment
No full textCoastal vegetated ecosystems including mangroves, seagrasses, and salt marshes are often shaped by positive plant-environment feedbacks. Plants improve their own living conditions with increasing patch size and density by attenuating hydrodynamics and stabilizing sediments. As these habitat modifications are critical for survival and growth, the positive density-dependent nature of these feedbacks can lead to establishment thresholds for young plants in absence of mature conspecifics. Although feedback strength is known to depend on hydrodynamic exposure and plant traits (e.g. stiff vs flexible stems), it remains unclear how (1) opposing morphological plant traits affect establishment in contrasting environments, and (2) whether trait plasticity influences establishment success. Here, we investigate this by transplanting two tidal species with opposing growing strategies – Spartina anglica forms tussocks of stiff stems while Zostera noltii forms patches of stress-avoiding flexible shoots – from two different donor sites in 8 experimental locations.
Results show that the survival and growth of both species was most successful at field locations with diverging environmental characteristics, while overall survival was highest for Z. noltii. Mainly, S. anglica survival was highest at locations with high organic matter and silt content and higher elevation relative to the tidal amplitude. In contrast, Z. noltii survival was highest at locations with larger grainsize and lower relative elevations. Furthermore, despite initial differences in plant traits between the two donor sites of Z. noltii, we found no effects of donor origin. Contrastingly, we found a significant effect of donor origin on S. anglica growth, even though transplants from the two donor sites showed no initial trait differences. Collectively, these results suggest that the stress-tolerance strategy of S. anglica hampers establishment in exposed conditions, whereas the stress-avoiding Z. noltii appears to be more susceptible to stress from desiccation and silty sediments