Staggering Decline In Deep-Sea Marine Life Expected By 2100 Due To Climate Change, With North Atlantic Hit Hardest
No place on this planet — even the deepest underwater world of flora and fauna, thousands of feet below the ocean — is free from the pervasive impacts of climate change, according to a new study published in Global Change Biology. The study for the first time quantifies the likely extent of marine life loss due to climate change impacts, and found that life in the North Atlantic is particularly at risk.
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The study, led by the National Oceanography Centre, applied the latest suite of climate models to identify the likely future changes in the food supply throughout the ocean world. The researchers were able to calculate the relationship between food supply and biomass of the globe's oceans with the help of a huge global database of marine life. The results, according to the researchers, show that most areas will experience negative change, with many animals and even species dying out.
"We were expecting some negative changes around the world, but the extent of changes, particularly in the North Atlantic, were staggering," Daniel Jones, the study's lead author said in a press release. "Globally we are talking about losses of marine life weighing more than every person on the planet put together." The extent of decline in North Atlantic is projected at nearly 38 percent over the next century, while the global changes will be of the order of over five percent.
To put it in perspective, the projected marine life loss, if weighed out, would weigh more than every person on the planet put together, Jones said.
The changes will be driven first by warmer and rainier weather, which will impact global ocean circulation and increase separation between water masses (known as "stratification"). This in turn will lower the amount of nutrients available to surface level plants and animals. As the surface level organisms die out, it will lead to a likely decline in ecosystem services like fishing (since surface level animals are the ones we eat). But their decline will also end up affected deeper dwelling creatures, since the surface level organisms typically die off and sink to the ocean floor, feeding deeper ecosystems. In addition, the study predicts that animals will get smaller and smaller - smaller organisms are more efficient in energy use, and as energy gets scarce, animals get smaller. This will likely exacerbate the issue of declining food sources.
According to the study, even sea floor communities living four or more kilometers under the surface of the ocean will be affected by projected changes. And although marine life changes are not consistent across the oceans, negative changes are projected for nearly every region. Losses in total biomass are predicted for nearly 80 percent of key ocean habitats including canyons, seamounts, and cold water coral reefs.
The study was part of the Marine Environmental Mapping Programme (MAREMAP), was funded by the Natural Environment Research Council (NERC), and involved researchers from several institutions including the National Oceanography Centre, Laboratoire des Sciences du Climat et de l'Environnement, France, the university of Tasmania and the Memorial University of Newfoundland, Canada.
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