Over the past decades, improvements in water quality—particularly increased oxygen and reduced nitrogen concentrations—have led to changes in phytoplankton biomass and community composition in the Schelde estuary, a macrotidal estuary in Belgium/SW Netherlands. We argue that these changes have affected SPM dynamics by modifying floc stability and size. Seasonal and spatial variability in SPM flocculation dynamics were examined...

Aim Greenland is among the most rapidly changing regions on Earth, with climate change having a profound impact on its terrestrial ecosystems. Here, moss‐associated diatoms hold great potential as sensitive biological indicators to monitor responses to climate change, but their diversity, community structure and biogeography remain virtually unexplored. Our study, thus, aims to (1) explore the diversity and community structure...

Aim Biogeographers have believed for a long time that the geographical distributions of protists are only determined by environmental conditions, because dispersal is not limited. During the past two decades, the field has come a long way to show that historical and spatial factors also significantly contribute to shaping protist distributions, calling for a reappraisal of our understanding of protist biogeography. Methods We...

Marine phytoplankton biomass dynamics are affected by eutrophication, ocean warming, and ocean acidification. These changing abiotic conditions may impact phytoplankton biomass and its spatiotemporal dynamics. In this study, we used a nutrient–phytoplankton–zooplankton (NPZ) model to quantify the relative importance of the bottom-up and top-down determinants of phytoplankton biomass dynamics in the Belgian part of the North Se...

Plankton comprises a large diversity of organisms, from pico- to macro-sized classes, and spans several trophic levels, whose population dynamics are characterized by a high spatio-temporal variability. Studies integrating multiple plankton groups, in respect to size classes and trophic levels, are still rare, which hampers a more thorough description and elucidation of the full complexity of plankton dynamics. Here, we presen...

Phaeocystis globosa is a nuisance haptophyte species that forms annual blooms in the southern North Sea and other coastal waters. At high biomass concentration, these are considered harmful algal blooms due to their deleterious impact on the local ecosystems and economy, and are considered an indicator for eutrophication. In the last two decades, methods have been developed for the optical detection and quantification of these...

Iron (Fe) is an essential nutrient for microalgal metabolism. The low solubility of Fe in oxic aquatic environments can be a growth-limiting factor for phytoplankton. Synthetic chelating agents, such as ethylenediaminetetraacetic acid (EDTA), are used widely to maintain Fe in solution for microalgal cultivation. The non-biodegradable nature of EDTA, combined with sub-optimal bioavailability of Fe-EDTA complexes to microalgae,...

At least two major drivers of phytoplankton production have changed in recent decades in the North Sea: sea surface temperature (SST) has increased by ~ 1.6°C between 1988 and 2014, and the nitrogen and phosphorus loads from surrounding rivers have decreased from the mid‐1980s onward, following reduction policies. Long time series spanning four decades (1975–2015) of nutrients, chlorophyll (Chl), and pH measurements in the Sou...

Benthic diatoms are important primary producers in intertidal marine sediments and form the basis of the food web in these ecosystems. In order to investigate the carbon flow within diatom mats, we performed in situ 13 C pulse‐chase labeling experiments and followed in detail the biochemical fate of carbon fixed by the diatoms for five consecutive days. These labeling experiments were done at approximately 2‐monthly intervals...

Diatoms living in intertidal sediments have to be able to rapidly adjust photosynthesis in response to often pronounced changes in light intensity during tidal cycles and changes in weather conditions. Strategies to deal with oversaturating light conditions, however, differ between growth forms. Motile epipelic diatoms can migrate to more optimal light conditions. In contrast, non‐motile epipsammic diatoms appear to mainly rel...

There is now ample evidence that biodiversity stabilizes aggregated ecosystem functions, such as primary production, in changing environments. In primary producer systems, this stabilizing effect is found to be driven by higher functional resistance (i.e., reduced changes in functions by environmental changes) rather than through higher functional resilience (i.e., rapid recovery following environmental changes) in more divers...

Summary The coccolithophore E miliania huxleyi plays a pivotal role in the marine carbon cycle. However, we have only limited understanding of how its life cycle and bacterial interactions affect the production and composition of dissolved extracellular organic carbon and its transfer to the particulate pool. We traced the fate of photosynthetically fixed carbon during phosphate‐limited stationary growth of non‐axenic, calcify...

This paper reviews the available knowledge on sedimentology, hydrodynamics and five major ecosystem components (microphytobenthos, vascular plants, terrestrial arthropods, zoobenthos, and avifauna) of Belgian sandy beaches. It covers the area from the foredunes to the lower foreshore, takes an ecosystem approach to beaches of this specific geographic area. Morphodynamically, Belgian beaches are (ultra‐)dissipative, macrotidal,...

Reconstructions of historical primary production, and of the algal groups and habitats that contribute to it, are fundamental in studies of climate and environmental change in both marine and freshwater environments. The aims of this study were to critically evaluate morphological and biogeochemical markers of diatom production by direct comparison of diatom marker pigments with absolute diatom biovolume and to partition diato...

The Late Quaternary climate history of the Larsemann Hills has been reconstructed using siliceous microfossils (diatoms, chrysophytes and silicoflagellates) in sediment cores extracted from three isolation lakes. Results show that the western peninsula, Stornes, and offshore islands were ice‐covered between 30 000 yr BP and 13 500 cal. yr BP. From 13 500 cal. yr BP (shortly after the Antarctic Cold Reversal) the coastal lakes...

Observational and experimental studies have shown that phagotrophic ciliates are highly selective predators. However, little is as yet known about the actual mechanisms involved in prey selection. We used direct behavioral observations to study the mechanism of prey selection in benthic algivorous ciliates feeding on mixed assemblages of diatom species. Four ciliate species, viz. three Strombidium species and a Pseudochilodono...