Climate models are now predicting a "staggering" catastrophe for deep sea marine life — a stark warning that even our planet's most remote ecosystems are not immune from the ravages of climate change.
The new study, led by the National Oceanography Centre, used various climate models to predict changes in food supply throughout the world's oceans. The scientists then looked at the relationship between food supply and biomass. Grimly, the models predict a 38% decline in seafloor-dwelling marine life in the North Atlantic, and 5% globally, by 2100.
In addition, the models suggest that more than 80% of all identified key seafloor habitats — like cold-water coral reefs, seamounts, and canyons — will suffer losses in total biomass. The scientists also predict that marine organisms will get increasingly smaller.
"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," noted lead author Daniel Jones in a statement. "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 changes to seafloor life will happen despite their presence, on average, some 2.5 miles (4 km) below the ocean surface; what happens up top will have a dramatic impact on the so-called bottom-feeders lying below. Deep sea creatures depend on the remains of surface ocean marine life sinking to the bottom. But life at the surface is set to decline, owing to a sharp decrease in the availability of nutrients — which will be caused by climate impacts like the slowing of global ocean circulation and stratification (the increased separation between water masses).
Read the entire study at Global Change Biology: "Multi-decadal range changes vs. thermal adaptation for north east Atlantic oceanic copepods in the face of climate change."