Arctic study of ocean acidification impacts
31st May 2012
As the UK approaches summer with high hopes of
good weather, a team of adventurous scientists will be setting sail
for far chillier climes. Thirty researchers from eight laboratories
will leave the UK on 1st June 2012 to study the effect
of ocean acidification on the Norwegian, Barents and Greenland
Seas.
They will travel as far north as polar ice will allow, collecting
seawater samples from both the open water and gaps in the sea-ice.
This study is the largest ever to examine the effects of altering
carbon dioxide (CO2) levels in “real world” seawater
samples directly after they are collected at sea.
Polar seas are expected to be especially
sensitive to the effects of ocean acidification, since more
CO2 dissolves in cold water, making Arctic waters a
valuable natural example of how the marine environment will respond
to a high CO2 world. Also, the chemical sensitivity of
surface seawater in the Arctic means that it will become corrosive
to calcium carbonate before anywhere else in the world. This could
pose a serious problem for marine plankton and other organisms that
use calcium carbonate for their shells or skeletons.
During the expedition, the scientists will
study the impact of the changing chemistry on marine organisms and
ecosystems, the cycling of carbon and nutrients in the sea and how
the sea interacts with the atmosphere to influence climate.
Two approaches will be used in this study.
Firstly, the researchers will look at how ecosystems vary between
areas where the chemistry of seawater is naturally more acidic or
alkaline. By contrasting the observations over a range of different
conditions, insights researchers will discover how acidification
may affect organisms living in their natural environment, where
natural selection and adaptation have had time to play out.
The second approach is experimental, using
tanks of natural seawater collected from the upper ocean and
brought into controlled conditions on deck. This natural seawater
will be subjected to various levels of CO2 that are
likely to occur in the future. The expedition, aboard the RRS
James Clark Ross, will end on 4th July in
Reykjavik, Iceland and members of the team will be blogging about
their progress at www.arcticoacruise.org/?cat=1.
Dr Ray Leakey, Arctic Research Theme Leader at
the Scottish Association for Marine Science (SAMS) and the leader
of the current expedition says, “Few studies have investigated
the effects of ocean acidification on the marine food web of the
remote Arctic seas, and most have focused on laboratory cultures or
natural communities from a limited number of relatively accessible
coastal locations. By contrast our expedition will be by ship in
both ice-covered and ice-free oceanic waters far from land. This
will allow us to undertake the most comprehensive study to date of
the ways in which the plants and animals living in the surface
waters of the Arctic ocean respond to acidification.”
Dr Toby Tyrrell from the National Oceanography
Centre and coordinator of the Sea Surface consortium added, “Following our cruise last year to the
northwest European shelf (for more information please see Notes to
Editors), this second cruise will visit the more remote Arctic
Ocean which may well be more seriously affected by ocean
acidification. The data collected will improve our understanding of
future impacts, providing important information about the
consequences of continuing to burn fossil fuels in enormous
quantities (atmospheric CO2 is already 40% above its
preindustrial level, and still climbing). Our final cruise, in 6
months time, will visit the other polar ocean, the Southern
Ocean.”
The global ocean has absorbed about a third of
the total CO2 produced by human activities in the past
200 years. This uptake of CO2 has greatly slowed
the rate of human-driven climate change. It is also responsible for
major changes to ocean chemistry, known as ocean acidification,
with potentially serious implications for marine life.
The research is part of the UK Ocean
Acidification Research Programme (UKOA), funded by the Natural
Environment Research Council (NERC), the Department of Environment,
Food and Rural Affairs (Defra) and the Department of Energy and
Climate Change (DECC).