Deep-Sea Marine Life Under Threat Due To Climate Change, Major Losses Likely By 2100

An international team of researchers have used advanced climate models to measure future loss of deep-sea marine life, and have found that even the most remote aquatic ecosystems are not safe from the impacts of climate change.

According to results of the research, published in the journal Global Change Biology, seafloor-dwelling marine life is predicted to decline by up to 38 percent in the North Atlantic and by more than five percent globally over the next century. These changes, which will also endanger human activities such as fishing, will be driven by a decline in the number of plants and animals that live near the surface of the oceans.

“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,” Daniel Jones, the study’s lead author said in a statement.

As part of the research, led by Europe’s National Oceanography Centre, scientists used the latest climate models to predict changes in food supply throughout the world's oceans. According to the researchers, seafloor communities are not expected to sidestep the changes despite living about 2.5 miles under the ocean's surface, because their food sources, which mainly consist of the remains of surface marine life that sink to the seafloor, will decrease due to a decline in nutrient availability.

Nutrient supplies, on the other hand, will suffer because of climate-driven changes such as a slowing of the global ocean circulation and an increased separation between water masses -- known as “stratification” -- as a result of warmer and rainier weather.

“We were expecting some negative changes around the world, but the extent of changes, particularly in the North Atlantic, were staggering,” Jones said. “Globally we are talking about losses of marine life weighing more than every person on the planet put together.”

The researchers mentioned that the projected changes in marine life are not consistent across the world, but said most areas will experience negative change, with more than 80 percent of all identified key habitats, such as cold-water coral reefs, seamounts and canyons, suffering losses in total biomass.

In addition, the study also predicted that marine animals will get smaller, and as smaller animals tend to use energy less efficiently, the change is likely to impact seabed fisheries, worsening the impact of overall declines in food supply from the planet's oceans.