A research cruise of the project Arctic Tipping Points (ATP) confirms the
spread of warm Atlantic waters further north into the Arctic. Now the
researchers conduct experiments on the collected samples in order to
establish the threshold of warming, causing abrupt changes in Arctic
ecosystems.
The cruise to the European sector of the Arctic Ocean on board the research
vessel Jan Mayen (University of Tromsø, Norway) encountered warm Atlantic
water invading areas previously occupied by cold arctic waters. The
northward displacement of warm atlantic waters is pushing key arctic biota
further north into the Arctic basin. Cruise leader Paul Wassmann (University
of Tromsø) reports that “the scarcity of the lipid-rich, arctic key species
Calanus glacialis appears to represent an early warning of an emerging
tipping point. The prominent seabird Little Auk on Svalbard feeds almost
exclusively on adult C. glacialis, but the feeding condition in the vicinity
of the colonies have deteriorated in recent years and Little Auks may get
extinct in years to come”.
The cruise was the inaugural activity of the Arctic Tipping Points (ATP)
project funded under Framework Program 7 of the EU. The term ‘tipping point’
commonly refers to a critical threshold at which minor perturbations can
qualitatively alter the state or development of a system. Because the Arctic
is warming about three times faster than the global rate, arctic ecosystems
are likely to encounter climate-driven thresholds and tipping points. This
may lead to abrupt ecological changes much sooner as compared with other
regions. The spectacular recent acceleration of arctic ice loss suggests
that climate change has entered a new phase. Indeed, the arctic ice pack has
been identified as one of the key tipping elements in the world climate
system, making change in the Arctic significant on a global scale. Current
models suggest that the Arctic Ocean will be largely ice-free in late
summer, with a cover of mostly first-year ice in winter in 2 decades from
now, or even earlier. “Such extensive changes in sea ice will have
unprecedented effects on arctic ecosystems. Establishing where and when
these tipping points will be reached is, therefore, a matter of urgency”,
states Project Coordinator Paul Wassmann.
Absence of Calanus glacialis
ATP will identify the elements of the Arctic marine ecosystem likely to show
abrupt changes in response to climate change. The research cruise found that
a small arctic crustacean, the copepod Calanus glacialis, a key node of the
arctic food web, was largely absent from regions surveyed where it was
previously abundant. “The northward displacement of the warm atlantic water
has been expected to displace arctic biota. The absence of Calanus glacialis
is consistent with model predictions and may already signal a major change
in the arctic food web”, says Elena Arashkevich, lead researcher in ATP of
the Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow.
Lab experiments
About 800 l of water collected during the ATP cruise entered the cold
chambers at The University Center in Svalvard (UNIS).
This volume was distributed in 20 l jars and installed into temperature
controlled baths maintaining temperature at each of seven different levels,
ranging from 1 - 9 ºC, increasing at 1.5 º C steps, thereby encompassing the
range of warming expected to occur in the Arctic during the 21st Century.
This experiment is one of the central activities of the ATP project.
The goal is to experimentally establish the threshold of warming beyond
which abrupt changes in the plankton community may occur. These changes are
expected to affect the structure of the plankton community as well as its
activity, and may involve a reorganization of the food web of the Arctic
Ocean, affecting its capacity to act as sink for CO2 as well.
"We are observing responses of microscopic planktonic organisms, with
generation times in the order of 1 day - assessed over 10 days. It is
evident that extrapolating from these experiments predictions of the changes
that may occur during the coming decades involves large uncertainties.
Indeed, the goal is not so much to establish these predictions, but to
provide a basis to test the predictions derived from models and theoretical
frameworks developed within the ATP project" says Carlos M. Duarte, lead
researcher at Consejo Superior de Investigaciones Científicas (Spain).
Input to climate models
Research cruises and experiments will be complemented by state-of-the-art
oceanographic-, ecological-, fisheries-, and economic models to determine
the effect of crossing those thresholds for the Arctic marine ecosystems,
and the associated risks and opportunities for economic activities dependent
on the marine ecosystem of the European Arctic. More broadly, ATP aims to
raise the attention of policy makers to the possibility of Arctic tipping
points at regional and global scales.
Impacts on regional and global scale
At the regional scales, ATP shall examine how institutions and policies for
the management of living marine resources, tourism and petroleum development
would cope with situations of very rapid change in ecosystems driven by
climate change. “This is an entirely new situation and will severely test
the ability of existing institutions to deliver policies that are
sustainable over time. ATP aims at to support the efforts of institutions in
the European Arctic to devise policies and strategies for coping with regime
shifts” says Anne-Sophie Crepin, social economist with the Beijer Institute
of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm.
At global scales, an understanding of tipping points and potential regime
shift in the Arctic ecosystem due to various levels of warming must be
considered in negotiations toward a new international agreement for climate
change regulation, and will be valuable for informing the EU position during
these negotiations. “The marginal ice zones are no longer the last frontier
of the unknown polar regions, but they become the trenches of the fight
against climate change”, concludes Paul Wassmann.
Project funded by Framework Program 7 of the EU
Total EU contribution: 5 million Euros
Period: 2009-2011
(Source: Arctic Tipping Points)
Contact:
Paul Wasmann, University of Tromsø (Norway):
paul.wassmann@uit.no
Carlos M. Duarte, Consejo Superior de Investigaciones Científicas (Spain):
carlosduarte@ifisc.uib-csic.es
Read more:
The project: www.eu-atp.org
Blogs:
www.eu-atp.org/wordpress
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The ATP cruise was conducted on the research vessel Jan Mayen owned by
the University of Tromsø (Photo: ATP)
13 European institutes contribute to ATP: University
of Tromsø (co-ordinator, Norway), Consejo Superior de Investigaciones
Cientifícas (Spain), Akvaplan-niva AS (Norway), SINTEF Fiskeri og
havbruk AS (Norway), Aarhus Universitet (Denmark), University of
Cambridge (UK), Institute of Oceanology Polish Academy of Sciences (Poland),
Center of Marine Sciences (Portugal), Université de Pierre et Marie
Curie (France), Greenland Institute of Natural Resources, Shirshov
Institute of Oceanology, Russian Academy of Sciences (Russia),
Max-Planck Gesellschaft zur Förderung der Wissenschaften e.V.,
Max-Planck-Institut für Meteorologie (Germany), The Beijer Institute of
Ecological Economics (Sweden). Map:
www.eu-atp.org
With the CTD-rosette 60 l of sea water can be sampled
from different depths (Photo: R. Caeyers).
There is currently high activity in the lab at UNIS in
Longyearbyen (Photo: ATP). |
