Climate change is turning parts of Antarctica
green, say scientists
Researchers map ‘beginning of new ecosystem’ as algae
bloom across surface of melting snow
Jonathan
Watts
@jonathanwatts
Published
onWed 20 May 2020 10.00 BST
Scientists
have mapped “the beginning of a new ecosystem” on the Antarctic peninsula as
microscopic algae bloom across the surface of the melting snow, tinting the
surface green and potentially creating a source of nutrition for other species.
The British
team behind the research believe these blooms will expand their range in the
future because global heating is creating more of the slushy conditions they
need to thrive.
In some
areas, the single-cell life-forms are so dense they turn the snow bright green
and can be seen from space, according to the study, published on Wednesday in
the journal Nature Communications.
Biologists
from the University of Cambridge and the British Antarctic Survey spent six
years detecting and measuring the green snow algae using a combination of
satellite data and ground observation.
The result
is the first large-scale algae map of the peninsular, which will be used as a
baseline to assess the speed at which the white continent is turning green due
to the climate crisis and potentially offering sustenance to other species.
They have
already found the algae have formed close bonds with tiny fungal spores and
bacteria. “It’s a community. This could potentially form new habitats. It’s the
beginning of a new ecosystem,” said Matt Davey of Cambridge University, one of
the scientists who led the study.
He
described the algae map as a missing piece of the carbon cycle jigsaw in the
Antarctic.
It
identifies 1,679 separate blooms of green snow algae, which together covered an
area of 1.9 sq km, equating to a carbon sink of about 479 tonnes a year. This
is equivalent to the emissions of about 875,000 car journeys in the UK, though
in global terms it is too small to make much of a difference to the planet’s
carbon budget.
Almost
two-thirds of the green algal blooms were found on small, low-lying islands
around the north of the peninsula, which has experienced some of the most
intense heating in the world, with new temperature records being set this
summer. The snow algae were less conspicuous in colder, southern regions.
Scientists
have previously observed an increase in green lichen and moss, but these grow
extremely slowly compared with algae. In future, they will also measure red and
orange algae and calculate how the presence of such colourful forms might be
affecting the heat-reflecting albedo quality of the snow.
“I think we
will get more large blooms in the future. Before we know whether this has a
significant impact on carbon budgets or bio albedo, we need to run the
numbers,” said Andrew Gray, the lead author of the paper.
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