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MEDIA RELEASE
7 June 2016
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Climate change takes a toll on critical marine species
Research from Victoria University of
Wellington and GNS Science has
revealed that algae critical to the marine
ecosystem are sensitive to climate
change.
The findings suggest that single-celled
marine algae—Antarctic diatoms—are
more prone to extinction during major
climatic changes and large-scale cooling
on Earth. Marine algae form the base of
the marine food web, are a crucial
element of the cycle of carbon dioxide,
and account for about fifty percent of the
world’s total biological productivity.
GNS Science and Victoria University paleontologist Professor James Crampton says large-scale
cooling millions of years ago stemmed from carbon dioxide fluctuations and changes in Earth’s
orbit and tilt.
“Climate does naturally vary a lot and there are swings in temperature over time, and diatom
communities can tolerate this general variability. But we found that past a certain threshold of
environmental change diatoms are vulnerable and some species become extinct and others
evolve.”
The researchers studied diatom fossil records from ocean sediments around Antarctica that date
back fifteen million years.
“Over that period diatoms in the Southern Ocean have experienced five major pulses of
extinction that are linked with particularly big and sharp temperature swings from warm to cold,”
Professor Crampton says.
“By using new analyses of large fossil data sets, we’ve been able figure out accurate times of
origination and extinction of the species and resolve what happened in a much finer timescale
than was possible previously.
“Our study shows that diatoms were affected by relatively rapid cooling in the past and appear to
be sensitive to major changes in the climate system. We suspect that a similar response may
occur during intervals of relatively rapid warming.”
The research will be published in Proceedings of the National Academy of Sciences of the United
States of America. Professor Crampton worked in collaboration with Dr Richard Levy from GNS
Science, Dr Robert McKay, Professor Tim Naish and Rosie Cody from Victoria University, and
Professor David Harwood from the University of Nebraska-Lincoln.
“Diatoms are an interesting group to focus on because of their ecological importance—everything
in the Antarctic marine ecosystem relies on them,” says Professor Crampton.
“In the future we plan to look at the flow-on effects further up the marine ecosystem and food
web, and whether other species that depend on the diatoms to survive become vulnerable as
well.”
For more information contact James Crampton on 027 264 4306 [email protected],
or Richard Levy on [email protected].
Issued by Victoria University of Wellington Communications & Marketing. Samantha Fisher, Communications Adviser, can be contacted by
[email protected] or phoning (04) 463 5105.