Introduction Currently, Arctic marine ecosystems are witnessing the most rapid physical changes worldwide, leading to shifts in pelagic and benthic communities food web structure, concomitant with introduction of boreal species. Gelatinous zooplankton or jellyfish represent one particular group which several species prone undergo significant poleward range expansions population increases course ongoing changes. Historically, were considered a trophic dead-end, but an increasing number...

Over the past decades, two key grazers in Southern Ocean (SO), krill and salps, have experienced drastic changes their distribution abundance, leading to increasing overlap of habitats. Both species occupy different ecological niches long-term shifts distributions are expected cascading effects on SO ecosystem. However, studies directly comparing salps lacking. Here, we provide a direct comparison diet fecal pellet composition using 18S metabarcoding fatty acid markers. Neither species'...

Arctic microbial communities (i.e., protists and bacteria) are increasingly subjected to an intrusion of new species via Atlantification uncertain degree ocean warming. As differ in adaptive traits, these oceanic conditions may lead compositional changes with functional implications for the ecosystem. In June 2021, we incubated water from western Fram Strait at three temperatures (2 °C, 6 9 °C), mimicking current potential future properties Ocean. Our results show that increasing temperature...

Abstract In Fram Strait, we combined underway-sampling using the remote-controlled Automated Filtration System for Marine Microbes (AUTOFIM) with CTD-sampling eDNA analyses, and high-resolution optical measurements in an unprecedented approach to determine variability plankton composition response physical forcing a sub-mesoscale filament. We determined biomass near surface horizontal resolution of ~ 2 km, addressed vertical at five selected sites. Inside filament, was tightly linked...

Sea ice is a large and diverse ecosystem contributing significantly to primary production in ice-covered regions. In the Arctic Ocean, sea consists of mixed multi-year (MYI), often several metres thick, thinner first-year (FYI). Current global warming most severe regions; as consequence, summer cover decreasing MYI disappearing at an alarming rate. Despite its apparent hostility, inhabited by microbial community bacteria protists, many which are photosynthetic. Here we present assessment...

Abstract Fram Strait, the gateway between Arctic and Atlantic Oceans, is undergoing major climate change‐induced physical biological transformations. In particular, rapid warming ongoing “Atlantification” are driving species range shifts altering food web structures in Arctic. Understanding predicting consequences of these processes on future ecosystems requires detailed assessments local pelagic biodiversity. Gelatinous zooplankton (GZP) an important component communities, recent evidence...

In this study, we created a dataset of continuous three-year 18S metabarcoding survey to identify eukaryotic parasitoids, and potential connections hosts at the Long-Term Ecological Research station Helgoland Roads. The importance parasites parasitoids for food web dynamics has previously been recognized mostly in terrestrial freshwater systems, while marine planktonic have understudied comparison those. Therefore, occurrence role remains unconsidered environment. We observed high abundances...

Abstract Reliable determination of organisms is a prerequisite to explore their spatial and temporal occurrence study evolution, ecology, dispersal. In Europe, Bavaria (Germany) provides an excellent system for research on the origin diversification freshwater including dinophytes, due presence extensive lake districts ice age river valleys. Bavarian environments are ecologically diverse range from deep nutrient‐poor mountain lakes shallow nutrient‐rich ponds. We obtained amplicon sequence...

Abstract Gelatinous zooplankton (GZP), i.e., ctenophores, cnidarian medusae, chaetognaths, appendicularians and salps, are considered climate change winners. This becomes particularly obvious in the Southern Ocean, which has undergone a significant shift from krill‐based to salp‐based ecosystem over last decades. A better knowledge on role of gelatinous invertebrates as prey is needed predict impact such shift. Until recently, GZP was “trophic dead end”. However, their true importance diets...

Dinoflagellates and diatoms are among the most prominent microeukaryotic plankton groups, they have evolved different functional traits reflecting their roles within ecosystems. However, links between metabolic processes environmental contexts warrant further study. The biodiversity of dinoflagellates was accessed with metatranscriptomics using Pfam protein domains as proxies for processes. Despite overall geographic similarity responses, abiotic (i.e., temperature salinity; ~800 domains)...

Abstract Marine community diversity surveys require a reliable assessment to estimate ecosystem functions and their dynamics. For these, non‐invasive environmental DNA (eDNA) metabarcoding is increasingly applied in zoological studies complement or even replace traditional morphological identification methods. However, uncertainties remain about the accuracy of detected with eDNA capture actual field. Here, we validate reliability identifying metazoan biodiversity highly dynamic marine...

Porcine enteroviruses (PEV) types 1-11 were assigned to three serologic groups by indirect immunofluorescence (IIF). Serotype group I consists of PEV 1-7 and 11 is correlated with CPE-type I. II represented type 8, producing II, while 9 10 are classified as serotype III cause III. Three isolates from the central nervous system pigs polioencephalomyelitis IIF but none established serotypes cross-neutralization. It concluded that these representatives two new for which designation PEV12 13 suggested.

Abstract The dynamics of diatoms and dinoflagellates have been monitored for many decades at the Helgoland Roads Long-Term Ecological Research site are relatively well understood. In contrast, small-sized eukaryotic microbes their community changes still much more elusive, mainly due to small size uniform morphology, which makes them difficult identify microscopically. By using next-generation sequencing, we wanted shed light on planktonic dynamics, including nano- picoplankton, during a...

Monitoring changes in eukaryotic microbial communities is critical for understanding ecosystem dynamics, trophic interactions and the impacts of climate change. Long-term time series are an important tool monitoring ecological communities, but from a single location may not be representative regional dynamics. In German Bight, Helgoland Roads such long-term series. Here, we consider spatial dynamics microbes as indicator representativeness site coastal which located North Sea. The community...

Plant diversity in the Arctic and at high altitudes strongly depends on rebounds to climatic environmental variability is nowadays tremendously impacted by recent climate warming. Therefore, past changes plant high-altitude regions are used infer through time allow future predictions. Sedimentary DNA (sedDNA) an established proxy for detection of local lake sediments, but still relationships between conditions preservation sedDNA far from being fully understood. Studying modern will improve...

Abstract Various field studies on plankton dynamics have broadened our understanding of seasonal succession patterns. Additionally, laboratory experiments described consumers ranging from generalists to selective grazers. While both approaches can give us a good the ecosystem and its dynamics, drawbacks in identification limited coverage left open questions generality previous results. Using an integrative approach, we investigated water samples taken at Helgoland Roads by metabarcoding...

Abstract. Information on recent biomass distribution and biogeography of photosynthetic marine protists with adequate temporal spatial resolution is urgently needed to better understand the consequences environmental change for ecosystems. Here we introduce review a molecular-based observation strategy high-resolution assessment these in space time. It result extensive technology developments, adaptations evaluations which are documented number different publications, results recently...

Climate change alters environmental conditions that are expected to have a profound effect on the biodiversity, community composition and metabolic processes of microeukaryotic plankton in Arctic Subarctic coastal waters. The molecular biodiversity (LSU rRNA gene) three size-fractions (micro-, nano-, picoplankton) from waters ice-influenced west Greenland was compared with fractions ice-free northwest Iceland within their summer context. Putative functions were determined by differentially...

The waters of Greenland harbour a high species richness and biomass gelatinous zooplankton (GZP); however, their role in the diet many fish species, including commercially exploited has not yet been verified. Traditionally, GZP was considered to be trophic dead end, i.e. with limited contribution as prey for higher levels. We applied DNA metabarcoding two gene fragments (COI, 18S V1–V2) stomach contents seven pelagic demersal waters, identify composition well occurrence predation. detected...

Communities of microscopic dinoflagellates are omnipresent in aquatic ecosystems. Consequently, their traits drive community processes with profound effects on global biogeochemistry. Species however not necessarily static but respond to environmental changes order maintain fitness and may differ cell size that scales physiological rates. Comprehending such trait characteristics is necessary for a mechanistic understanding plankton dynamics resulting biogeochemical impacts. Here we used...

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 571:43-57 (2017) - DOI: https://doi.org/10.3354/meps12134 Sea ice origin and sea retreat as possible drivers of variability in Arctic marine protist composition Kristin Hardge1,2,*, Ilka Peeken1, Stefan Neuhaus1, Thomas Krumpen1, Thorsten Stoeck3, Katja Metfies1, 2 1Alfred Wegener Institute, Helmholtz Centre...

Ecological stability under environmental change is determined by both interspecific and intraspecific processes. Particularly for planktonic microorganisms, it challenging to follow dynamics over space time. We propose a new method, microsatellite PoolSeq barcoding (MPB), tracing allele frequency changes in protist populations. successfully applied this method experimental community incubations field samples of the diatom Thalassiosira hyalina from Arctic, rapidly changing ecosystem....