Nature

07
Apr

Underwater Antarctic Biodome Will Create ‘Future Ocean’ Inside to Test Acidification

If you’re a marine creature, your future is frighteningly uncertain. Apart from vast patches of plastic and the threat posed by underwater mining, you also have to contend with steadily rising CO2 levels. Not only are fossil fuel emissions driving temperatures up, they’re also permeating the oceans, creating a chemical solution sometimes called carbonic acid. Ocean acidification, as it’s commonly known, is perhaps the biggest threat to marine life today.

Divers explore below the ice off the coast of Antarctica.

Because cold water holds more CO2, cold parts of the ocean are even more susceptible to acidification. (To visualize this, think of a bottle of soda—when cold, it’s sparkling with bubbles, but when warm, it quickly goes flat.) Scientists can forecast a range of potential effects, but to get good, hard numbers, they also have to run a few experiments. Which is why Australian marine biologists Jonny Stark and Donna Roberts are building underwater biodomes.

Jo Chandler, reporting for Yale e360:

Within the chambers of their laboratory, which will be dropped 20 meters below the frozen crust of a little Antarctic bay just south of the Australian government’s Casey Station, Roberts, Stark, and their colleagues will introduce a selection of plants and animals from the local seafloor community to the more acidic seawater conditions anticipated by 2100. In the ensuing four months, the scientists will maintain the artificial conditions in the chambers via an umbilical system fed through a hole bored in three-meter-thick ice.

Such experiments aren’t without precedent. Duke University started a similar project in its experimental forest back in 1994, raising rings of towers that pumped out CO2. The goal was to study how higher concentrations would affect trees and other organisms. The Australian underwater dome project will do essentially the same thing for the ocean. The system will have four chambers—two serving as controls—each about the size of a coffee table.

So far, ocean pH has fallen by 0.1, making our oceans 26% more acidic than they were before the industrial revolution. By 2100, Chandler notes, they could be 170% acidic, further endangering shellfish, plankton, corals, and more.

To learn more about ocean acidification, read Woods Hole Oceanographic Institution senior scientist Scott Doney’s primer here on NOVA Next.

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