Their results, which are published this month in the Journal of Geophysical Research, show that there is a mismatch between what goes into the Arctic Ocean and what comes out.
This is the first study to look at the transport of dissolved inorganic nutrients nitrate, phosphate and silicate together, all of which are essential for life in the ocean. The study combined measurements of nutrient concentrations with measurements of how much water was transported across the main Arctic gateways – Davis Strait, Fram Strait, the Barents Sea Opening and Bering Strait – in summer 2005.
Growth of the tiny plants at the base of marine food chains, microalgae, in the Arctic Ocean is fuelled by nutrient inputs from the Pacific and Atlantic Oceans, and from rivers around the Arctic Ocean rim. These riverine inputs are increasing as a result of increasing temperatures, because nutrients previously locked up in frozen soils – or 'permafrost' – are being released as the permafrost thaws.
While scientists are trying to understand how this increase in nutrients is influencing the growth of Arctic microalgae, the final fate of the nutrients is also of interest because they may support marine ecosystems elsewhere, carried there by ocean currents.
In the study, the researchers looked at all oceanic inputs and outputs of the three nutrients. They found that the nitrate coming into the Arctic Ocean balanced how much goes out. But for silicate and phosphate, more goes out into the North Atlantic than comes into the Arctic Ocean.
"These findings have important implications," says Dr Sinhué Torres-Valdés of the National Oceanography Centre, lead author of the paper.
"Firstly, the imbalances indicate that the Arctic Ocean is an important source of phosphate and silicate to the North Atlantic. Secondly, while nitrate transports are balanced, in the Arctic large amounts of nitrogen are lost to the atmosphere as nitrogen gas through a process called denitrification."
So where do the extra nutrients come from?
"Data suggest that rivers can provide most of the silicate that is transported to the North Atlantic, which implies that further alterations on Arctic river nutrient loads will have a direct impact on nutrient transports to the Atlantic.
"In the case of nitrate and phosphate, no obvious sources seem to provide enough to offset the imbalance. We are therefore investigating the possibility that the extra nitrate and phosphate comes from dissolved organic matter – the decaying remains of microorganisms in the ocean and decaying remains from soils in river loads.
"We suggest that this work can serve as a baseline for monitoring how nutrient availability varies as the Arctic continues to respond to the changing climate," says Dr Torres-Valdés.
The study, funded by the Natural Environment Research Council as part of the International Polar Year project 'Arctic Synoptic Basin-wide Oceanography', was a collaboration between the National Oceanography Centre, University of Southampton Ocean and Earth Science, Institute of Ocean Sciences Canada, Bedford Institute of Oceanography, Alfred Wegener Institute for Polar and Marine Research, and University of Alaska Fairbanks.
The paper 'Export of nutrients from the Arctic Ocean' was featured in Research Spotlight of EOS Transactions, American Geophysical Union.
Notes for editors
1. Reference: Torres-Valdés, S., T. Tsubouchi, S. Bacon, A. C. Naveira-Garabato, R. Sanders, F. A. McLaughlin, B. Petrie, G. Kattner, K. Azetsu-Scott, and T. E. Whitledge (2013), Export of nutrients from the Arctic Ocean, J. Geophys. Res.: Oceans, 118, doi:10.1002/jgrc.20063
2. Research Spotlight, EOS Transactions, American Geophysical Union highlights exciting new research from AGU journals. The paper was featured in Volume 94, Number 13, 26 March 2013.
3. The photo was taken during one of the expeditions to the Arctic aboard the Russian icebreaker Kapitan Dranitsyn in 2008 as part of the International Polar Year NERC-funded project Arctic Synoptic Basin-wide Oceanography (ASBO). The image shows the back of the icebreaker, which was carving out a circular opening in the ice at a sampling station. Credit Sinhué Torres-Valdés.
4. The National Oceanography Centre (NOC) is the UK's leading institution for integrated coastal and deep ocean research. NOC operates the Royal Research Ships James Cook and Discovery and develops technology for coastal and deep ocean research. Working with its partners NOC provides long-term marine science capability including: sustained ocean observing, mapping and surveying, data management and scientific advice.
5. NOC operates at two sites, Southampton and Liverpool, with the headquarters based in Southampton.
6. Among the resources that NOC provides on behalf of the UK are the British Oceanographic Data Centre (BODC), the Marine Autonomous and Robotic Systems (MARS) facility, the National Tide and Sea Level Facility (NTSLF), the Permanent Service for Mean Sea Level (PSMSL) and British Ocean Sediment Core Research Facility (BOSCORF).
7. The National Oceanography Centre is wholly owned by the Natural Environment Research Council (NERC).
Catherine Beswick, National Oceanography Centre
Catherine Beswick | EurekAlert!
Further reports about: > American Geophysical Union > Arctic Ocean > Atlantic mollies > EOS > Environment > Environment Research > Facility Management > Marine science > Natural Environment Research > Oceanography > Pacific Ocean > Polar Day > Synoptic > deep ocean > food chain > marine ecosystem > sea snails
A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg
Urbanization to convert 300,000 km2 of prime croplands
27.12.2016 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction