A new study shows that the consequences of climate change are already affecting the deep sea, and its inhabitants may soon be in danger.
A team of scientists has analyzed how climate change will affect deep-sea biodiversity. While they found that the surface water is warming significantly faster, the ocean floor has already been affected, and its inhabitants will undergo drastic changes soon. The study was published in the scientific journal Nature Climate Change.
“We used a metric known as climate velocity, which defines the probable speed and direction in which a species changes as the ocean warms,” explains Isaac Brito-Morales, a marine biologist and doctoral student at the University of Queensland, Australia, in a statement.
“We calculated the climate velocity throughout the ocean for the past 50 years and then for the rest of this century using data from 11 climate models,” adds the researcher.
The results suggest that the global average climate velocity in the deepest and darkest layers of the ocean – more than a thousand meters deep – increased almost four times faster than at the surface in the second half of the 20th century.
And things are only expected to get worse in the coming decades. By the end of this century, in the mesopelagic zone – from 200 to 1,000 meters deep below the surface of the ocean – climate velocity is projected to accelerate four to 11 times more than on the surface.
If these data are correct, this will have a huge indirect effect on all oceans, since the mesopelagic zone is home to a wide variety of small fish that support larger animals, such as tuna and squid.
Changes in climate velocity have a more severe impact on the deep sea, since the temperature is generally quite uniform and constant compared to surface waters, which are continually affected by atmospheric conditions. Even small changes in the deep sea can disrupt the broader ecosystem.