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No full textSeegräser galten lange als unspektakuläre Gewächse der Küsten. Mittlerweile hat sich jedoch herausgestellt, dass sie nicht nur vielen Meeresbewohnern Lebensraum bieten, sondern auch beträchtliche Mengen des Klimagases CO2 speichern und damit eine wichtige Rolle im Kohlenstoffhaushalt der Erde spielen. Meeresforscher versuchen daher, die bedrohten Seegraswiesen zu retten und neue anzupflanzen
The chromosomal genome sequence of the giant barrel sponge, Xestospongia muta Schmidt 1870 and its associated microbial metagenome sequences
No full textWe present a genome assembly from a specimen of Xestospongia muta (Caribbean barrel sponge; Porifera; Demospongiae; Haplosclerida; Petrosiidae). The genome sequence has a total length of 158.52 megabases. Most of the assembly (99.56%) is scaffolded into 15 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 18.99 kilobases in length. Several symbiotic bacterial genomes were assembled as MAGs, including Candidatus Poribacteria species, Candidatus Latescibacteria, Acidobacteriota, Actinomycetota Gemmatimonadota, multiple Chloroflexota and the archaeon Nitrosopumilus. Gene annotation of this assembly on Ensembl identified 20,220 protein-coding genes
Ocean bottom seismometers provide direct measurements of pulsed-structure and turbulence of turbidity currents overspilling from a submarine channel
No full text5. Wochenbericht SO316 CAVA Tephras
No full textFS SONNE Ausfahrt SO316 - CAVA Tephras,
21.11. – 26.12.2025, Balboa (Panama) – San Diego (USA
Glacial Southern Ocean deep water Nd isotopic composition dominated by benthic modification
No full textThe deep Southern Ocean (SO) circulation plays a key role in the storage and release of CO2 in Earth's climate system. The uptake and release of CO2 strongly depend on the redistribution of well and poorly ventilated deep ocean water masses. Recently, evidence was found for possible stronger Pacific deep water overturning and subsequent intrusion into the SO during periods of reduced AMOC. Here, we present new authigenic neodymium isotope data (epsilon Nd) from two sites within the Atlantic sector of the SO to assess the distribution of water masses during the past 150 ka. PS 1768-8 (3299 m) and ODP 1093 (3624 m) feature unradiogenic interglacial epsilon Nd-signatures, which are typical for present-day Weddell Sea sourced Antarctic Bottom Water (AABW) (epsilon Nd similar to - 8.6). During peak glacial periods, radiogenic epsilon Nd-values ranging from similar to -2.5 to -3.5 are recorded. This may be the result of either a strong Pacific or benthic flux influence on the Nd budget in the Atlantic sector of the SO. However, an ocean circulation model indicates no stronger Pacific influence during glacials. Thus, we suggest that an increase in benthic flux influences the SO Nd budget, which is modulated by ACC strength. The more stratified and more sluggish deep water supports decreased vertical mixing and increased glacial carbon storage without the intrusion of poorly ventilated Pacific waters. The occurrence of highly radiogenic glacial bottom water or porewater signatures requires reassessment of the glacial Southern Hemisphere epsilon Nd-endmember for water mass sourcing reconstructions in the glacial Atlantic
Tracing the Neovolcanic zone along the sediment-covered regions of the Red Sea Rift
No full textThe Red Sea Rift is an ultra-slow spreading rift filled with Miocene salt and younger sediments. While volcanic features can be observed in exposed areas in the southern Red Sea Rift, evidence of volcanism in the sediment-blanketed regions in the central and northern Red Sea Rift has been lacking, leaving open whether the mid-ocean rift axis continues beneath them. Here, we present new multichannel seismic and high-resolution bathymetric data of these blanketed regions. Our data reveals multiple instances where oceanic crust can be traced beneath the evaporite cover, forming volcanic edifices protruding through the sediment cover. We identify abundant circular depressions in the sediment cover as volcanic craters, which formed by deep-sea explosive volcanism or caldera collapses. The common occurrence of volcanic features in the sediment-covered regions supports the continuous formation of oceanic crust along large parts of the Red Sea Rift
5. Wochenbericht M207
No full text04.01.-11.02.2025
Belém – Mindelo
5. Wochenbericht
27.01.-02.02.202
Monitoring ecological consequences of marine munition in the Baltic Sea 2024 - Cruise No. AL615, 2nd – 12th July 2024, Kiel (Germany) – Kiel (Germany), „MecoMM-BS I - III“
No full textALKOR cruise AL615 took place as part of the project CONMAR (https://conmarmunition.eu/) which is part of the DAM mission sustainMare (https://www.sustainmare.de/). It was the continuation of the munition monitoring started within the BMBF‐funded project UDEMM (Environmental Monitoring for the Delaboration of Munition in the Sea; https://udemm.geomar.de/), the EMFF (European Maritime and Fisheries Fund) ‐funded projects BASTA (Boost Applied munition detection through Smart data detection in and AI workflows; https://www.basta‐munition.eu) and ExPloTect (Ex‐situ, near‐real‐time detection compound detection in seawater). In addition, the cruise was part of the accompanying monitoring, which is to be carried out in parallel with the immediate munition clearance programme. However, as the munition clearance work could not start as planned in June, only the status prior to the clearance work could be documented on the AL615 cruise.
ALKOR worked for eleven days in the Baltic Sea in the munition dumpsites Kolberger Heide and Lübeck Bight. Munition sites were mapped via hydroacoustic (multibeam echosounder and synthetic aperture sonar) and visual (AUV and ROV) methods. Water samples were taken for explosive-type compounds analysis via CTD and ROV. A change of crew happened on the 8th July in Neustadt i.H. with support of the Federal Police.
Zusammenfassung
Die ALKOR-Fahrt AL615 fand im Rahmen des Projekts CONMAR (https://conmarmunition.eu/) als Teil der DAM-Mission sustainMare (https://www.sustainmare.de/) statt. Sie war die Fortsetzung der Munitionsüberwachung, die im Rahmen des BMBF-geförderten Projekts UDEMM (Umweltmonitoring für die Delaborierung von Munition im Meer; https://udemm.geomar.de/) und der vom EMFF (Europäischer Meeres- und Fischereifond) geförderten Projekte BASTA (Boost Applied munition detection through Smart data detection in and AI workflows; https://www.basta-munition.eu) und ExPloTect (Ex-situ, near-real-time detection compound detection in seawater) begonnen wurde. Darüberhinaus diente die Fahrt dem begleitenden Monitoring, welches parallel zum Munitionsräumung Sofortprogramm durchgeführt werden soll. Da die Räumarbeiten jedoch nicht wie geplant im Juni starten konnten, konnte auf der AL615 lediglich der Status vor den Räumarbeiten dokumentiert werden.
ALKOR arbeitete elf Tage lang in der Ostsee in den Munitionsversenkungsgebieten Kolberger Heide und Lübecker Bucht. Die Munitionsversenkungsgebiete wurden mit hydroakustischen- (Fächerecholot und SAS - Sonar mit synthetischer Apertur), sowie visuellen (AUV und ROV) Methoden kartiert. Zur Analyse der Verteilung und Konzentration von STVs (Sprengststofftypischen Verbindungen) wurden Wasserproben per CTD und ROV genommen. Der Wechsel der Besatzung fand am 08. Juli in Neustadt i.H. mit Unterstützung der Bundespolizei statt