Climate change alters the globe in many ways, and new
research by the University of Hawai`i shows that even the deep ocean is changed
fundamentally.
(Image: Samples of Hawaiian gold coral Kulamanamana haumeaae, which can live for thousands of years, were
collected during a HURL Pisces V submersible dive. The submersible’s robotic
arm is visible in the picture. The image is the cover shot on the current issue
[Jan. 2, 2014] of the journal Nature. Credit: UH Hawaii Undersea Research Laboratory, DSRV
Pisces Pilot Max Cremer.)
The chemical processes in the North Pacific around Hawai`i
are showing signs of significant alteration—a change that appears clearly
associated with climate change, according to a new paper in Nature.
The Hawaii Undersea Research Laboratory (HURL) at the University
of Hawaii-Manoa School of Ocean and Earth Science and Technology (SOEST),
working with researchers from the Lawrence Livermore National Laboratory (LLNL)
and the University of California-Santa Cruz analyzed deep-sea corals gathered
near the Hawaiian Islands using the HURL Pisces V submersible.
By studying the skeletal layers of the slow-growing and very
old corals, they were able to assess changes in the nitrogen levels in the
ocean. The researchers were able to track changes in the ocean food web over
the past 1,000 years from their studies of the ancient corals.
For most of that 1,000 years, the levels bounced around by a
small amount. Then, as the Industrial Revolution began changing the makeup of
the atmosphere and the Little Ice Age came to an end, the levels changed.
The research showed that nitrogen fixation—the process by
which living things take up nitrogen from the atmosphere or water—has increased
by roughly 20 percent in the North Pacific over the past roughly 150 years. And it found
that the increase is still going on.
"This...has very significant implications about how
we understand, and perhaps, can better predict effects of global warming in the
Pacific, but also likely in other subtropical regions," Tom Guilderson of
LLNL said.
Citation: Increasing
subtropical North Pacific Ocean nitrogen fixation since the Little Ice Age. Owen
A. Sherwood, Thomas P. Guilderson, Fabian C. Batista, John T. Schiff and
Matthew D. McCarthy. Nature, doi:10.1038/nature12784
© Jan TenBruggencate 2014
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