While climate change is of global concern, its impacts are especially rapid and pronounced in Arctic ecosystems. Arctic glaciers have been particularly impacted, with increasing melt and retreat in conjunction with shifts in riverine freshwater and sediment discharge. Arctic fjords are the ultimate recipients of glacial discharge and a plethora of heavy metals released from glacial environments. ...

The polar regions are biologically productive and play a critical role in regional and global biogeochemical cycling. A key nutrient is dissolved silicon, required for the growth of siliceous phytoplankton, diatoms, which form an important component of polar ecosystems. Glacial weathering is thought to be an important dissolved silicon source to coastal waters, especially critical in regions ...

Arctic marine systems are vital to the Earth’s ecological and climatic balance and harbour a unique biodiversity adapted to extreme conditions. However, they are under unprecedented threat from climate change, in particular from “Atlantification”, i.e., the loss of sea ice and the increasing influence of Atlantic Water (AW) in this region. Long-term observatories are crucial to detect even small ...

Antarctic sea ice is one of the largest biomes on Earth providing a critical habitat for ice algae. Measurements of primary production in Antarctic sea ice remain scarce and an observation‐based estimate of primary production has not been revisited in over 30 years. We fill this knowledge gap by presenting a newly compiled circumpolar data set of particulate and dissolved organic carbon from 362 ...

Methane, a potent greenhouse gas, is increasingly recognized to be emitted from newly deglaciated environments, particularly in the Arctic, yet due to data scarcity these sources remain underrepresented in global methane budgets. Deglaciation leads to the expansion of proglacial terrains, driving the formation of an increasing number of proglacial lakes worldwide, especially in Greenland. Small to ...

Diatom resting stages can remain viable in sediments for decades and germinate when exposed to suitable environmental conditions, inoculating the water column and the surface sediments with new populations of cells. Classical methods, based on acid-cleaning of diatom frustules in sediment samples, do not discriminate between living and dead cells and may destroy the more fragile taxa. We used a ...

Cold seeps and cold-water corals (CWCs) coexist on Northern Norway's continental shelf at the Hola trough between Lofoten and Vesterålen. Here, cold seeps release methane from the seabed, yet none reaches the sea surface. Instead, the methane dissolves and disperses in the ocean where it is ultimately consumed by methane-oxidizing microorganisms. These microorganisms metabolize methane and release ...

Strain localization within crustal shear zones involves intricate feedback between deformation mechanisms, metamorphic reactions and fluid circulation. Despite evidence that these high-deformation zones proceed at least partly through dissolution-precipitation creep, available creep laws so far only account for dislocation creep and/ or solid-state diffusion processes. Deciphering the role and ...

Seabed gas and oil emissions appear as bubble plumes ascending through the water column in various environments. Understanding bubble characteristics—size, rise speed—is important for estimating escape rates of fluids like methane, oil, and carbon dioxide. However, measuring underwater gas bubbles is challenging, often requiring expensive specialized equipment. This study presents a novel methodology ...

Xenophyophores are large, agglutinated foraminifera that dominate the benthic megafauna in some parts of the deep sea. Here, we describe an assemblage of largely fragmentary specimens from the Clarion-Clipperton Zone (CCZ), an area of the eastern abyssal Pacific hosting large, commercially significant deposits of polymetallic nodules. We recognised 18 morphospecies of which eight yielded DNA sequences. ...