cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25850/nioz/7b.b.sc
title: Chapter 4 - Algal-induced biogeomorphic feedbacks lay the groundwork for coastal wetland development

description: Coastal wetlands provide valuable ecosystem services, including biodiverse habitats, carbon sequestration potential and nature-based flood defense. The establishment of saltmarsh vegetation and other key wetland species on bare tidal flats relies on windows of opportunity, which are traditionally linked to physical factors such as hydrodynamic conditions, substrate stability and drainage. However, observations on tidal flats suggest that plant seedlings settle in high densities on raised sedimentary ridges colonized by mats of primitive filamentous algae (Vaucheria sp.). Such algal-covered ridges were previously shown to have higher sediment strength than substrate without algae. Here, we investigated whether these measurements can be explained by physical processes only, or that biological (Vaucheria-induced) processes influence early saltmarsh establishment through the formation of stabilized bedforms. We performed two experiments under controlled mesocosm conditions, to test the hypotheses that i) Vaucheria grows better on elevated topographic relief, ii) the binding force of their algal filaments increases sediment strength, which consequently iii) maintains and creates elevated topographic relief on which algal growth is further facilitated. The existence of this algal-induced biogeomorphic feedback cycle was confirmed in our experiments. Our findings reveal that halophytic plants are not the only important ecosystem engineer in coastal wetlands, but that fast-growing, mat- forming species like Vaucheria also play a major role by creating stable and elevated sedimentary relief. Our study indicates that biota can widen the windows of opportunity for ecosystem establishment, which can be utilized to optimally design managed coastal realignment projects that aim at the restoration of coastal ecosystems.
DOI: 10.25850/nioz/7b.b.2c
title: Co-evolution of the terrestrial and aquatic ecosystem in the Holocene Baltic Sea

description: The Baltic Sea experienced changes in marine input throughout the Holocene as substantial regional ice retreat led to isostatic adjustment, eustatic sea level change, and periodic isolation from the North Sea. Here, we determine the distributions and isotopic signatures of organic compounds preserved in a sediment record spanning the last ~ 11 ka to reconstruct environmental change under these dynamic conditions. Carbon and hydrogen isotope ratios of short-, mid-, and long-chain n-alkanes, along with long-chain diol and glycerol dialkyl glycerol tetraether abundances, were analyzed in sediments sampled from the Arkona Basin in the southwestern Baltic Sea. In the earlier part of the record (specifically 10 ? 8.2 ka), hydrogen isotope values of higher plant-derived n-alkanes revealed a change in dominant water source from an ice melt-derived to a precipitation-dominated hydrological regime. Following this shift in water source, carbon isotope values of n-alkanes suggest diversification of vegetation. Shifts in hydrology and vegetation did not coincide with established phase boundaries, but instead occurred mid-phase or spanned phase transitions. For this reason, we suggest describing the Ancylus Lake in two phases: a meltwater phase (10.6 to 9.2 ka) and a precipitation phase (9.2 to 7.7 ka). Our results highlight the utility of using C and H isotope ratios in conjunction with other compound abundance proxies to better understand the complex environmental change recorded in paleo archives.
DOI: 10.25850/nioz/7b.b.uc
title: Chapter 5 - Tidal flat transitions signaled by self-organized algal patterns

description: To understand the establishment of vegetated coastal wetlands, we combined mathematical modelling and a field study to investigate the emergence of algal-covered sedimentary ridges that constitute distinct spatial patterns on tidal flats. Strikingly, these patterned bedforms appear to facilitate the establishment of saltmarsh vegetation. We measured plant seedling densities in the field, which showed that seedling densities are higher on elevated bedforms colonized by the filamentous algae Vaucheria. Based on these field measurements and earlier laboratory experiments, we developed a mathematical model under the hypothesis that the bedform patterns are self-organized due to algal-induced scale-dependent feedbacks (filaments increase sediment strength, creating elevated ridges where algal growth is further improved; algal growth is inhibited adjacent to ridges due to scour and inundation). Model simulations confirmed this hypothesis, as they reproduced the wide range of observed Vaucheria patterns, varying from no cover to parallel ridges and from branching networks to full algal cover. Moreover, we used the model to explain the observation that large mudflat areas remain topographically smooth and bare (i.e., no algal mats nor plants) for years despite the development of algal-covered bedform patterns elsewhere on the mudflat at similar elevation. We found that the scale-dependent feedbacks make both the configurations with smooth mud and with algal bedforms highly resilient to changes in environmental conditions, such that these two configurations can coexist as alternative stable state under a range of mudflat elevations. Furthermore, we showed that changes in the spatial complexity of the algal pattern indicate imminent tipping points that lead to ecosystem collapse or establishment. Our study sheds light on processes that might be highly relevant for wetland restoration and conservation projects. Such projects could benefit from ecosystem engineers like Vaucheria and the signaling value of their spatial patterns.
DOI: 10.25850/nioz/7b.b.qb
title: Comparing CLE-AdCSV applications using SA and TAC to determine the Fe binding characteristics of model ligands in seawater

description: Competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-AdCSV) is used to determine the conditional concentration ([L]) and the conditional binding strength (logKcond) of dissolved organic Fe-binding ligands, which together influence the solubility of Fe in seawater. Electrochemical applications of Fe speciation measurements vary predominantly in the choice of the added competing ligand. Although different applications show the same trends, [L] and logKcond differ between the applications. In this study, binding of two added ligands in three different common applications to three known types of natural binding ligands are compared. The applications are: 1) Salicylaldoxime (SA) at 25 micromol (SA25) and short waiting time, 2) SA at 5 micromol (SA5) and 3)2-(2-thiazolylazo)-rho-cresol (TAC) at 10 micromol, the latter two with overnight equilibration. The three applications were calibrated under the same conditions, although having different pH values, resulting in the detection window centers (D) DTAC &gt; DSA25 &gt;/= SA5 (as log D values with respect to Fe3+: 12.3&gt;11.2&gt;/= 11). For the model ligands, there is no common trend in the results of logKcond. The values have a considerable spread, which indicates that the error in logKcond is large. The ligand concentrations of the non humic model ligands are underestimated by TAC and overestimated by SA25 which we attribute to the lack of equilibrium between Fe-SA species in the SA25 application. The application TAC more often underestimated the ligand concentrations and Application the application SA5 was best in estimating over and under estimated the ligand concentration correctly. The trends between these model ligand concentrations were similar for all three applications. The estimated ligand concentrations for the humic and fulvic acids differed approximately by a factor 22 fold between TAC and SA5 and another factor of 2 between SA5 and SA25. The use of SA above 5 micromol suffers from the formation of the species Fe(SA)x (x&gt;1) that is not electro-active as already suggested by Abualhaija and Van den Berg (2014). Moreover, we found that the reaction between the electro-active and non-electro-active species is probably irreversible. This undermines the assumption of the CLE principle, causes overestimation of [L] and could result in a false distinction into more than one ligand group. For future electrochemical work it is recommended to take the above limitations of the applications into account. Overall, the uncertainties arising from the CLE-AdCSV approach mean we need to search for new ways to determine the organic complexation of Fe in seawater.
DOI: 10.25850/nioz/7b.b.j
title: Comparison of organic and palynological proxies for biomass burning and vegetation

description: Continental fire and vegetation history have been widely studied in sedimentary archives using palynological proxies (i.e. charcoal abundance and the pollen assemblage) and organic proxies (i.e. the anhydrosugars levoglucosan and it isomers, and plant-wax n-alkanes), but rarely in concert. Here, we compared palynological and organic proxies to reconstruct fire and vegetation history in a sediment core from Lake Allom on Fraser Island, Australia, covering the last 5.4 kyrs. We found that anhydrosugar and microscopic charcoal accumulation rates had similar trends, while trends in macroscopic charcoal accumulation rates were different. This was attributed to the short distance over which macroscopic charcoal is transported compared to microscopic charcoal and anhydrosugars. Furthermore, differences in fire regime and combusted types of vegetation may also explain the differences in levoglucosan and charcoal accumulation rates in lacustrine sediments. Moreover, we found that the ratios between anhydrosugars seem to be governed by combustion conditions and not by type of burned vegetation. Long chain n-alkane accumulation rates and stable isotope compositions showed similar patterns as the pollen assemblage throughout the last 5.4 kyrs, with both representing the local vegetation history. Collectively, our results showed that in the period between 5.4 and 4 ka, biomass burning was low on Fraser Island, while at 4 ka, fire occurrence started to increase, in absence of changes in vegetation and hydrology. Therefore, we suggest that increased fire activity on Fraser Island around 4 ka might have been caused by human-lit biomass burning, since aboriginals settled on Fraser Island around this time.
DOI: 10.25850/nioz/7b.b.6c
title: Coralreef imagery Curacao 1973 (I-10)

description: This dataset covers the imagery from 1973 for transect I at 10 m water depth, as part of the long term monitoring program on coral reef dynamics in Curacao coastal waters (Rolf Bak, Erik Meesters Andreas Haas). B negatives (Kodak Tri-X) were scanned with Epson Perfection V850 Pro scanner at a resolution of 2400 dpi and saved in tif format.
DOI: 10.25850/nioz/7b.b.9g
title: Co-occurring intertidal ecosystem engineers with opposing growth strategies show opposite responses to environmental gradients during establishment

description: Coastal 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.
DOI: 10.25850/nioz/7b.b.0c
title: Counting using deep learning regression gives value to ecological surveys.

description: Many ecological studies rely on count data and involve manual counting of objects of interest, which is time-consuming and especially disadvantageous when time in the field or lab is limited. However, an increasing number of works uses digital imagery, which opens opportunities to automatise counting tasks. In this study, we use machine learning to automate counting objects of interest without the need to label individual objects. By leveraging already existing image-level annotations, this approach can also give value to historical data that were collected and annotated over longer time series (typical for many ecological studies), without the aim of deep learning applications. We demonstrate deep learning regression on two fundamentally different counting tasks: (i) daily growth rings from microscopic images of fish otolith (i.e., hearing stone) and (ii) hauled out seals from highly variable aerial imagery. In the otolith images, our deep learning-based regressor yields an RMSE of 3.40 day-rings and an R^2 of 0.92. Initial performance in the seal images is lower (RMSE of 23.46 seals and R^2 of 0.72), which can be attributed to a lack of images with a high number of seals in the initial training set, compared to the test set. We then show how to improve performance substantially (RMSE of 19.03 seals and R^2 of 0.77) by carefully selecting and relabelling just 100 additional training images based on initial model prediction discrepancy. The regression-based approach used here returns accurate counts (R^2 of 0.92 and 0.77 for the rings and seals, respectively), directly usable in ecological research.
DOI: 10.25850/nioz/7b.b.0g
title: Cruise report 64PE485 - ReViFES Borkum reef grounds

description: This cruise was carried out for the ReViFES project. The rationale behind this cruise and project is to find out what the scale of ecosystem services of reef structures are in the North Sea. The focal area was the Borkum Reef grounds on the border of the Dutch - German continental shelf, situated approximately 20 km offshore (north) from the island of Schiermonnikoog. In 2018 WWF started an experiment in this area by creating a man made European flat Oyster reef on an area of 100 ? 100 m. Close to the site of the man-made oyster reef is a small rocky reef and a well developed Lanice conchilega reef. Aim of the project is to compare biodiversity and ecosystem functioning of these reef structures to the surrounding area without reef like structures.
DOI: 10.25850/nioz/7b.b.9d
title: Cruise Report 64PE407

description: Cruise Report for cruise nr. 64EP407; Public version (GDPR compliant)
DOI: 10.25850/nioz/7b.b.1g
title: Cruise report 64PE505 - ReViFES Brown Bank, Frisian Front, Borkum reef grounds

description: This cruise was carried out for the ReViFES project. The rationale behind this cruise and project is to find out what the scale of ecosystem services of reef structures are in the North Sea. The initial focal area was the Brown Bank, an areas west of the Dutch coast near the Dutch-UK border, characterised by a shallow sand bank (~20 m deep) flanked by deep troughs (~40 m) in an otherwise ~30 m deep region. In 2017-2019 a Sabellaria spinulosa reef was observed (van der Reijden et al. 2019; van der Reijden et al. 2021) in the eastern and western trences next to the bank. The revifes team aimed to revisit these reefs and investigate the ecosystem services provided by the reef. However, the reefs were not observed and the team could not execute the plan. Therefore, an alternative location with recent observations of Sabellaria near the Frisian Front north of Texel (unpublished data Bureau Waardenburg) was surveyed as well. Again, the observed reefs were not detected. Then it was decided to spend the last 6 research days on investigating the Borkum Reef grounds on the border of the Dutch - German continental shelf, situated approximately 20 km offshore (north) from the island of Schiermonnikoog. This site had been studied in 2020 (Witbaard et al. 2021) and 2021 (Coolen et al. 2021).
DOI: 10.25850/nioz/7b.b.zg
title: Cruise report 64PE524 - ReViFES

description: This cruise was carried out for the ReViFES project ?North Sea Reef Vitalization for Ecosystem Services (North Sea ReViFES)?. The ReViFES project started in 2020 and aims to investigate in how far reefs in the North Sea provide additional value to ecosystem biodiversity and functioning, including ecosystem services such as food provision, spill over of commercial species, carbon storage and increased food web complexity. To attain this, the project studies multiple types of reefs in the North Sea, including flat oysters (Ostrea edulis), mussel beds (Mytilus edulis), Ross worm (Sabellaria spinulosa), sand mason (Lanice conchilega), horse mussels (Modiolus modiolus) and geogenic reefs (rocks). The aim is to generalise observations across all these reef types and assess how reefs with high densities of flat oysters differ from the other types. The project aims to investigate reefs in the most undisturbed form possible, realising that any reefs in the North Sea will have been influenced by humans. The various aspects of the project are investigated by filming the seabed using a drop cam / towed video system, sediment grabs (box corer Hamon grab), water samples, zooplankton traps, eDNA and the placement of cages to catch large species such as fish, crabs, whelks and lobsters. The ReViFES carried out by a consortium of the Netherlands Institute of Sea Research, Wageningen University Research, Waardenburg Ecology, TU Delft, van Oord, WWF, the North Sea Foundation, the Ministry of LNV, Ark, CIV den Oever, Natuur Milieu, Roem van Yerseke, Sas Consultancy and is funded by NWO TTW Open Technology programme (project number 17671) with cofunding from the consortium partners.
DOI: 10.25850/nioz/7b.b.2g
title: Cruise report N2111 - ReViFES Voordelta

description: This cruise was carried out for the ReViFES project. The rationale behind this cruise and project is to find out what the scale of ecosystem services of reef structures are in the North Sea. The focal area was the Voordelta shellfish reef close to the coast of Ouddorp, province of South Holland, the Netherlands. Aim of the project is to compare biodiversity and ecosystem functioning of reef structures such as shellfish reefs to the surrounding area without reef like structures.
DOI: 10.25850/nioz/7b.b.tf
title: CTD seawater dissolved inorganic carbon and total alkalinity for R/V Sonne cruise SO289.

description: This dataset contains 395 measurements (all from the CTD rosette) of seawater dissolved inorganic carbon (DIC) and total alkalinity (TA) from the South Pacific Ocean. The samples were collected during R/V Sonne cruise SO289 in February-April 2022, as part of the GEOTRACES GP21 research programme to build an understanding of the distribution, origins, and depletions of trace elements and their isotopes (TEIs) in a lesser-explored ocean region. Measurements for TA and DIC were carried out using a VINDTA 3C instrument (#014, Marianda, Germany). All analysis was conducted at the NIOZ Royal Netherlands Institute for Sea Research. Bad results from technical issues during analysis have been removed from these results, so there are no recognised issues. The NIOZ created the metadata entry and is responsible for holding master copies of the data.
DOI: 10.25850/nioz/7b.b.kc
title: CTD seawater dissolved inorganic carbon, total alkalinity and nutrients for R/V Sonne cruise SO279.

description: This dataset contains 77 measurements (all from the CTD rosette) of seawater dissolved inorganic carbon (DIC), total alkalinity (TA) and nutrients (Si, PO4, NH4, NO3 and NO2) from the Azores Region (North Atlantic Ocean). The samples were collected during R/V Sonne cruise SO279 in Dec 2020, as part of the NAPTRAM research programme to build an understanding of the transport pathways of plastic and microplastic debris in the North Atlantic. Measurements for TA and DIC were carried out using a VINDTA 3C instrument (#017, Marianda, Germany) and nutrients were analysed using a Seal QuAAtro, gas-segmented continuous flow analyser. All analysis was conducted at the NIOZ Royal Netherlands Institute for Sea Research. Bad results from technical issues during analysis have been removed from these results, so there are no recognised issues. The data were collected as part of an international effort from the JPI Oceans project HOTMIC and BMBF project PLASTISEA, and forms a joint effort of HOTMIC and PLASTISEA researchers from a range of countries and institutes. The NIOZ created the metadata entry and is responsible for holding master copies of the data.
DOI: 10.25850/nioz/7b.b.td
title: Data from manuscript "distance doesn't matter: migration strategy in a seabird has no effect on survival or reproduction"

description: Migrating animals show remarkable diversity in migration strategies, even between individuals from the same population. Migrating longer distances is usually expected to be costlier in terms of time, energy expenditure and risks with potential repercussions for subsequent stages within the annual cycle. Such costs are expected to be balanced by increased survival, for example due to higher quality wintering areas or lower energy expenditure at lower latitudes. We compared reproductive parameters and apparent survival of lesser black-backed gulls (Larus fuscus) breeding in the Netherlands, whose winter range extends from the UK to West Africa, resulting in one-way migration distances that differ by more than 4500 km. Individuals migrating furthest arrived later in the colony than shorter-distance migrants, but still laid in synchrony with the colony and consequently had a shorter pre-laying period. This shorter pre-laying period affected neither egg volumes nor hatching success. We found no relationship between migration distance and apparent survival probability, corresponding with previous research showing that annual energy expenditure and distance travelled throughout the year is similar across migration strategies. Combined, our results indicate an equal fitness payoff across migration strategies, suggesting there is no strong selective pressure acting on migration strategy within this population.