1,822 results match your criteria: "Alfred Wegener Institute[Affiliation]"

Article Synopsis
  • Climate change is altering habitats in the Arctic Ocean, affecting migrating baleen whales like blue and fin whales, leading to changes in their range and presence in Arctic waters.
  • A study using passive acoustic monitoring in Fram Strait from 2012 to 2021 reveals that blue whales are primarily present from July to October, with some winter activity, while fin whales peak in mid-summer to autumn with some winter and sporadic spring presence.
  • Environmental factors such as zooplankton mass and sea surface temperature influence the acoustic presence of blue and fin whales, with no significant trends in the timing of their presence over the years, indicating Fram Strait is an important feeding ground for these species.
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Biodiversity and Hemolytic Toxicity of the Genus (Dinophyceae) in the Beibu Gulf, China.

Mar Drugs

November 2024

Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education, Nanning Normal University, Nanning 530001, China.

Article Synopsis
  • The study focuses on the biodiversity of a dinoflagellate genus in the Beibu Gulf, identifying several strains associated with harmful algal blooms (HABs) in the Western Pacific Ocean.
  • Researchers utilized light and scanning electron microscopy alongside genetic sequencing techniques (LSU rDNA and ITS) to morphologically characterize and phylogenetically analyze six strains, discovering two distinct ribotypes and one new ribotype.
  • Notable findings include the morphological characteristics of the strains, the identification of a new ribotype, and the absence of hemolytic toxicity in some strains, which enhances our understanding of dinoflagellate species and their potential impacts in the region.
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Offshore wind farms (OWFs) pose new anthropogenic pressures on the marine environment as the erosion of turbine blades release organic and inorganic substances with potential consequences for marine life. In the present study, possible effects of the released particles and their chemical constituents on the metabolic profile of the blue mussel, Mytilus edulis, were investigated, utilizing H NMR spectroscopy. In the lab, mussels were exposed for 7 and 14 days to different concentrations (10 and 40 mg L) of microplastic (MP) particles which were derived from cryo-milled rotor blade coatings and core materials (glass fiber polymer, GFP).

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Evolutionary genomics of the emergence of brown algae as key components of coastal ecosystems.

Cell

November 2024

Sorbonne Université, CNRS, Algal Genetics Group, Integrative Biology of Marine Models Laboratory, Station Biologique de Roscoff, Roscoff, France. Electronic address:

Article Synopsis
  • Brown seaweeds are vital to coastal ecosystems, but they are threatened by climate change, prompting a detailed genetic study.
  • The research traced the evolutionary history of brown algae, highlighting significant gene families and metabolic pathways related to their adaptation and functional diversity.
  • Findings also indicated that the integration of large viral genomes has played a crucial role in shaping the genetics and traits of brown algal species over time.
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Background: Over their evolutionary history, corals have adapted to sea level rise and increasing ocean temperatures, however, it is unclear how quickly they may respond to rapid change. Genome structure and genetic diversity contained within may highlight their adaptive potential.

Results: We present chromosome-scale genome assemblies and linkage maps of the critically endangered Atlantic acroporids, Acropora palmata and A.

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Article Synopsis
  • Evidence of Antarctic ozone recovery has been observed, but Arctic ozone recovery remains uncertain 25 years after the peak of ozone-depleting substances.
  • A Dynamic Linear Model was used to analyze data from ozonesondes over 20-year periods (1994-2022), revealing no detectable recovery in lower Arctic stratospheric ozone.
  • Significant positive trends were found before 2017 at some measurement stations, but trends since 2019 have been notably negative, underscoring the need for ongoing monitoring of Arctic ozone levels.
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A new micro-destructive technique for high-resolution water isotope analysis of ice samples using a Laser Ablation (LA) system coupled with a Cavity Ring Down Spectrometer (CRDS) is presented. This method marks the first time water isotope analysis is conducted directly on the ice, bypassing the traditional steps of melting and vaporizing the ice sample, thanks to the direct transition of ice into water vapour through the laser ablation process. A nanosecond ArF laser ablation system (193 nm) with an integrated two-volume ablation chamber was successfully coupled to a CRDS analyzer, utilizing nitrogen as the carrier gas.

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Article Synopsis
  • The European flat oyster, a vital part of marine ecosystems and a key economic resource, has seen its habitats drastically decline, leading to functional extinction.
  • Recent studies compiled data from 1524 to 2022 to reveal past locations and extents of flat oyster fisheries and reefs, highlighting where these ecosystems once thrived.
  • These datasets aim to support flat oyster restoration efforts and improve adaptive management strategies while helping recover overlooked histories of ocean ecosystem changes caused by human activities.
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Microbes perform critical functions in corals, yet most knowledge is derived from the photic zone. Here, we discover two mollicutes that dominate the microbiome of the deep-sea octocoral, Callogorgia delta, and likely reside in the mesoglea. These symbionts are abundant across the host's range, absent in the water, and appear to be rare in sediments.

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Author Correction: Holocene thinning in central Greenland controlled by the Northeast Greenland Ice Stream.

Nat Commun

October 2024

Departamento de Física de la Tierra y Astrofísica, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Madrid, Spain.

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The Last Interglacial period (LIG) was characterized by a long-term Arctic atmospheric warming above the preindustrial level. The LIG thus provides a case study of Arctic feedback mechanisms of the cryosphere-ocean circulation-climate system under warm climatic conditions. Previous studies suggested a delay in the LIG peak warming in the North Atlantic compared to the Southern Ocean and evoked the possibility of southward extension of Arctic sea ice to the southern Norwegian Sea during the early LIG.

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Author Correction: Hidden impacts of ocean warming and acidification on biological responses of marine animals revealed through meta-analysis.

Nat Commun

October 2024

CNR-IAS, Consiglio Nazionale delle Ricerche, Instituto per lo studio degli Impatti Antropici e Sostenibilità in ambiente marino. Località Sa Mardini, 09170, Torregrande, Oristano, Italy.

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Bromine in ice cores has been proposed as a qualitative sea ice proxy to produce sea ice reconstructions for the polar regions. Here we report the first statistical validation of this proxy with satellite sea ice observations by combining bromine enrichment (with respect to seawater, Br) records from three Greenlandic ice cores (SIGMA-A, NU and RECAP) with satellite sea ice imagery, over three decades. We find that during the 1984-2016 satellite-era, ice core Br values are significantly correlated with first-year sea ice formed in the Baffin Bay and Labrador Sea supporting that the gas-phase bromine enrichment processes, preferentially occurring over the sea ice surface, are the main driver for the Br signal in ice cores.

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Oxygen isotopes (δO) are the most commonly utilized speleothem proxy and have provided many foundational records of paleoclimate. Thus, understanding processes affecting speleothem δO is crucial. Yet, prior calcite precipitation (PCP), a process driven by local hydrology, is a widely ignored control of speleothem δO.

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The anaerobic oxidation of alkanes is a microbial process that mitigates the flux of hydrocarbon seeps into the oceans. In marine archaea, the process depends on sulphate-reducing bacterial partners to exhaust electrons, and it is generally assumed that the archaeal CO-forming enzymes (CO dehydrogenase and formylmethanofuran dehydrogenase) are coupled to ferredoxin reduction. Here, we study the molecular basis of the CO-generating steps of anaerobic ethane oxidation by characterising native enzymes of the thermophile Candidatus Ethanoperedens thermophilum obtained from microbial enrichment.

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Hydrothermal vents emit hot fluids enriched in energy sources for microbial life. Here, we compare the ecological and biogeochemical effects of hydrothermal venting of two recently discovered volcanic seamounts, Polaris and Aurora of the Gakkel Ridge, in the ice-covered Central Arctic Ocean. At both sites, persistent hydrothermal plumes increased up to 800 m into the deep Arctic Ocean.

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Ecological stability is a vital component of natural ecosystems that can inform effective conservation and ecosystem management. Furthermore, there is increasing interest in making comparisons of stability values across sites, systems and taxonomic groups, often using comparative synthetic approaches, such as meta-analysis. However, these synthetic approaches often compare/contrast systems where measures of stability mean very different things to the taxa involved.

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Unexpected Delayed Incursion of Highly Pathogenic Avian Influenza H5N1 (Clade 2.3.4.4b) Into the Antarctic Region.

Influenza Other Respir Viruses

October 2024

Centre for Pathogen Genomics, Department of Microbiology and Immunology, at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia.

The current highly pathogenic avian influenza H5N1 panzootic is having substantial impacts on wild birds and marine mammals. Following major and widespread outbreaks in South America, an incursion to Antarctica occurred late in the austral summer of 2023/2024 and was confined to the region of the Antarctic Peninsula. To infer potential underlying processes, we compiled H5N1 surveillance data from Antarctica and sub-Antarctic Islands prior to the first confirmed cases.

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Direct and indirect effects of copepod grazers on community structure.

J Plankton Res

September 2024

Department of Marine Sciences, University of Gothenburg, Carl Skottsbergs gata 22B, Gothenburg 41319, Sweden.

Ecological theory and empirical research show that both direct lethal effects and indirect non-lethal effects can structure the composition of communities. While the direct effects of grazers on marine phytoplankton communities are well studied, their indirect effects are still poorly understood. Direct and indirect effects are inherently difficult to disentangle in plankton food webs.

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Variation in thermal physiology can drive the temperature-dependence of microbial community richness.

Elife

September 2024

Department of Life Sciences, Silwood Park Campus, Imperial College London, Ascot, United Kingdom.

Predicting how species diversity changes along environmental gradients is an enduring problem in ecology. In microbes, current theories tend to invoke energy availability and enzyme kinetics as the main drivers of temperature-richness relationships. Here, we derive a general empirically-grounded theory that can explain this phenomenon by linking microbial species richness in competitive communities to variation in the temperature-dependence of their interaction and growth rates.

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With the ongoing climate and oceanographic change, an increasing number of studies are reporting dramatic population losses caused by thermal extremes in intertidal habitats. Under moderate warming, however, populations can fare better in places where species normally experienced suboptimal temperatures. This article reports the massive recruitment of the barnacle on the Gulf of St.

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Article Synopsis
  • * Recent climate simulations indicate that MHWs and THEs in the Arctic Ocean are expected to intensify because of sea ice decline and ongoing warming trends.
  • * The mean intensity of MHWs in the Arctic is projected to increase significantly during the 21st century, becoming over seven times greater than the global average, highlighting an urgent need for conservation efforts.
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Modern microbiology: Embracing complexity through integration across scales.

Cell

September 2024

Department of Earth and Planetary Sciences, University of California, Berkeley, Berkeley, CA, USA; Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA; Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia; Department of Environmental Science Policy, and Management, University of California, Berkeley, Berkeley, CA, USA. Electronic address:

Microbes were the only form of life on Earth for most of its history, and they still account for the vast majority of life's diversity. They convert rocks to soil, produce much of the oxygen we breathe, remediate our sewage, and sustain agriculture. Microbes are vital to planetary health as they maintain biogeochemical cycles that produce and consume major greenhouse gases and support large food webs.

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