From CBS News: Underwater eruption, dead fish may give clues to climate change
(LiveScience) An underwater volcano that erupted near the Canary
Islands off the coast of Africa is giving scientists a closer look at
how ocean ecosystems could respond to climate change, from dying fish to
The ecosystem responded much as the
researchers would have expected to the high temperatures and changes in
acidity caused by the uneasy volcano south
of El Hierro island. But the strength of the response was a surprise,
study researcher Eugenio Fraile-Nuez of the Instituto Español de
Oceanografía in Spain told LiveScience.
"The physical and
chemical response of the system was predictable, but we never have
imagined that we would reach this magnitude," Fraile-Nuez said.
eruption killed or drove away all of the fish in the region (though
many were seen floating dead on the ocean's surface), the researchers
found. Some phytoplankton, or the floating plants that sit at the bottom
of the ocean food chain, were able to adapt.
October 2011, a new volcano formed south of El Hierro island, which is
part of Spain. It was the first chance in 500 years to watch the local
ecosystem evolve in response to an eruption, Fraile-Nuez said. He and
his colleagues have been monitoring the volcano since then, measuring
its effect on ocean temperature, salinity, carbon dioxide content and
Over the crater, the water heated up by as much as 65
degrees Fahrenheit (18.8 degrees Celsius), the researchers found.
Dissolved oxygen in the water all but disappeared, decreasing by 90
percent to 100 percent in places. Meanwhile, carbon and carbon dioxide
values shot up, and the pH of the water went down by 2.8, meaning it
became more acidic.
Fish died or disappeared in the wake of the underwater eruption,
which also killed a massive amount of plankton in deep waters. In their
place, a community of carbon-eating bacteria sprung up, many of which
shone with bright green fluorescence. At the surface, plankton seemed to
adapt to warmer waters and the addition of new elements such as copper,
Link to climate change
Increase in temperature, decrease in oxygen and a more acidic pH is exactly what scientists would expect to be the result of global warming for
the ocean, Fraile-Nuez said. As the oceans take up more and more carbon
dioxide from the atmosphere, scientists predict they'll respond much as
the area around El Hierro has to the volcanic eruption -- though not
necessarily on the same scale.
Understanding the changes caused
by the volcanic eruption will help researchers predict how the oceans
will respond to certain levels of the greenhouse gas carbon dioxide,
"The orders of magnitude in which we are moving
will help us to have a future vision of how the marine ecosystem of El
Hierro would adapt to such changes," he said.
Fraile-Nuez and his colleagues detailed their results online this week in the open-access journal Scientific Reports.