By David KingThis story was originally published in the BBC World Service and is reproduced here with permission.
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The Antarctic sea is the most remote place on Earth, and researchers have been working for decades to understand the extent to which life has been lost to global warming.
But new research published in Nature suggests that some of the species on the planet may have been wiped out by global warming even before humans were here to colonise the region.
Researchers from the US National Oceanic and Atmospheric Administration (NOAA) and the University of California, Berkeley have mapped a vast network of floating, underwater forests, where marine life thrived.
This was previously thought to be entirely absent from the world’s oceans.
Researchers had previously mapped these forests in the US and Europe, but there was no clear picture of how widespread these forests were in the Antarctic.
“The question of what caused the loss of species and what species are still alive in the region is really an important one,” said Michael Farr, a researcher at the University Of Queensland in Australia.
“It really shows us the biodiversity in the oceans is not as uniform as we thought it was.”
While some of these species are alive, scientists are now trying to understand why they are gone.
In the US, for example, the study found that more than one species of sea turtle was found in one place in the ocean.
“There is a lot of research out there to try to understand how the world is changing, what is driving this, and what are the implications,” said Scott Ritchie, an oceanographer at the National Oceanography Centre in Seattle.
“But it’s very hard to make predictions about the future.
So I think we are really at the beginning of a new era in marine ecology.”
What scientists know about the effects of global warmingIn addition to studying the extent of the loss, the scientists also used data to investigate how the sea has changed since the early 1900s.
“We’re not going back in time and looking at the ocean to see how much it’s changed,” said Farr.
“This study gives us the tools to understand what is going on in the deep ocean and the way we are living in the last 20 years.”
In particular, the team studied the ocean’s currents, which are what drive ocean currents, as well as currents in the sea floor and in the upper water column.
“What we found is that the world has been warming for more than 20 years, so there are many changes that are happening in the water that are not visible to the naked eye,” said co-author Richard A. Wilson, a geochemist at the Woods Hole Oceanographic Institution in Massachusetts.
“So we are looking at what is causing these changes in the world that we’re seeing.”
The researchers also studied the effects the oceans have had on the way species are living and feeding.
“I think it is important to understand these changes, because these are important drivers of the evolution of the world,” said Ritchie.
“If we don’t understand these, we don.
We’re losing species and ecosystems.”
This is not the first time the team has looked at the effects global warming has had on ocean ecosystems.
In 2009, they also found that the sea level in the North Pacific region had risen by an average of 4cm (1.5 inches) a year over the last 100 years.
The scientists also looked at a few key variables in the data they used to map the biodiversity of the ocean and found that some species were doing better than others.
For example, a species that lives in the Southern Ocean in the northern hemisphere was found to have more species than one that lives only in the Pacific.
The researchers say the data also supports the idea that a global warming climate could have contributed to the loss.
“Global warming may have reduced the biomass of some of those species,” said Wilson.
“These species are not able to move around, they don’t have a lot to eat and so the loss may have accelerated over time.”
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