Impacts of climate change in the deep sea
Even the most remote deep-sea ecosystems are affected by climate change according to a study conducted by the National Oceanography Centre at the University of Southampton, UK. According to the study, seafloor dwellers will decline by up to 38% in the North Atlantic and over 5% globally over the next century because of a reduction in the ocean’s surface plants and animals.
The international research team, using advanced climate models, is quantifying future losses in deep-sea marine life.
These results are based upon the use of climate models that quantify losses allowing researchers to predict changes in the ocean's food supply globally. By applying a relationship between food supply and the calculated biomass of the global database of marine life, accurate predictions are determined. The results are published this week in the scientific journal Global Change Biology.
Despite living on average four kilometers under the surface of the ocean, seafloor communities are expected to see radical changes. Researchers have gone backwards in the process by first predicting that nutrient supplies will suffer because of climate impacts of things like the slowing of the global ocean circulation, increased separation of water masses, known as 'stratification', due to the warmer, rainier weather. Surface plants and animals whose remains would have become sustenance for the deep-sea life will also decline making food scarce for all deep-sea life.
Lead author Dr. Daniel Jones says: "There has been some speculation about climate change impacts on the seafloor, but we wanted to try and make numerical projections for these changes and estimate specifically where they would occur. We were expecting some negative changes around the world, but the extent of changes, particularly in the North Atlantic, were staggering. Globally we are talking about losses of marine life weighing more than every person on the planet put together."
The projected changes in marine life are not consistent across the world, but most areas will experience negative change. Over 80% of all identified key habitats, such as cold-water coral reefs, seamounts and canyons, will suffer losses in total biomass. The analysis also predicts that animals will get smaller. Smaller animals tend to use energy less efficiently, thereby impacting seabed fisheries and exacerbating the effects of the overall declines in available food.
Read more at the National Oceanography Centre of University of Southampton.
Image via Smithsonian Science.