Without sea ice, polar cod go hungry

Polar cod fulfil a key role in the Arctic food web, as they are a major source of food for seals, whales and seabirds alike. But the polar cod themselves might soon be the hungry ones. Under the ice of the central Arctic, the juvenile fish are indirectly but heavily dependent on ice algae. As a result, retreating sea ice could have far-reaching impacts on the food web. Though researchers have long since suspected this relation existed, an international team of researchers led by the Alfred Wegener Institute (AWI), Helmholtz Centre for Polar and Marine Research, have now successfully confirmed it.

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Litter levels rise up in the Arctic Ocean

Next to warming and acidification, one of the most prominent problems of the oceans is littering. Several hundred thousand tons of litter is drifting in the oceans of the world and levels are rising. The Arctic Ocean is no exception: in just ten years, the concentration of marine litter at a deep-sea station in the Arctic Ocean has risen 20-fold. This was recently reported in a study by researchers at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI).

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Arctic Sea ice on the retreat

The Arctic sea ice diminishes every year more and more. In 2012, it had reached a sad negative record with its extension of 3.4 million square kilometers. This year, the extension reached its second lowest value with 4.1 million square kilometers which is even less than the previous record in 2007. And according to experts from the Alfred-Wegener-Institute, who had been responsible for the measurements, the trend will continue.

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Researchers successfully simulate sea ice leads in the Arctic Ocean

Scientists from the Alfred-Wegener-Institute (AWI) and the University of Hamburg have succeeded in realistically simulating the emergence of large channels in the Artic sea ice in a computer model. Two approaches were decisive for this success: On the one hand, the researchers had increased the spatial resolution of the FESOM AWI sea-ice ocean model. On the other hand, they were able to improve the numerical solution to the equation so that the simulation of the lead formation holds up well when compared to real sea-ice satellite data. They reported this success in a study that appeared online in the professional journal, Geophysical Research Letters.

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Warmer winters will thaw permafrost beneath shallow Arctic lakes

Permafrost below shallow Arctic lakes is thawing as a result of changing winter climate, new research shows. These rates of warming are similar to those observed in terrestrial permafrost, yet those soils are still well below freezing and thaw is not expected for at least another 70 years. However, a regime shift in lake ice is leading to sub-lake permafrost thaw now.

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New gardener for AWI “Hausgarten”

Scientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) are setting out with the research vessel Polarstern towards Spitsbergen, to use newly developed equipment in the Arctic Ocean. Autonomous instruments on the seabed, in the water column and in the air will complement the long-term measurements of the deep-sea research group. In this way researchers can analyse the climatic changes in the Arctic and their impact on the fauna in the future with higher temporal and spatial resolution.

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Methane from the Arctic Ocean might not reach the atmosphere

When talking about greenhouse gases, people usually talk about carbon dioxide. However, methane is considered much more potent as a greenhouse gas despite much lower levels in the atmosphere. The debate about the origin of increased levels of methane in the atmosphere has triggered a number of research projects. Now, the Norwegian Center for Arctic Gas Hydrate, Environment and Climate has found evidence that only very little of the gas seeping from the seabed of the Arctic Ocean also reaches the atmosphere.

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Sea Ice Plays a Pivotal Role in the Arctic Methane Cycle

The ice-covered Arctic Ocean is a more important factor concerning the concentration of the greenhouse gas methane in the atmosphere than previously assumed. Experts from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) report on the newly discovered interactions between the atmosphere, sea ice and the ocean in a recent online study in the journal Nature’s Scientific Reports.

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Microplastics found in waters off Svalbard, raising more concerns about Arctic Ocean pollution

Tiny plastic particles, so called microplastics, from personal-care products and plastic waste, are accumulating in marine waters and big lakes around the world. They haven now also been showing up in Arctic waters south and southwest of Svalbard, Norway, raising concerns that they are entering the Arctic food web.

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Billions of juvenile fish under the Arctic sea ice

Using a new net, marine biologists from the Alfred Wegener Institute have, for the first time, been able to catch polar cod directly beneath the Arctic sea ice with a trawl, allowing them to determine their large-scale distribution and origin. This information is of fundamental importance, as polar cod are a major source of food for seals, whales and seabirds in the Arctic. The study, which was recently published in the journal Polar Biology, shows that only juvenile fish are found under the ice, a habitat the researchers fear could disappear as a result of climate change.

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