Before the Industrial Revolution, the average ocean pH was around 8.2. Today, it sits at roughly 8.1—a seemingly small change, but one that translates to a 30% increase in acidity. Given that the pH scale is logarithmic, this means a slight drop can significantly impact marine organisms. For Antarctic marine life, many of which are finely tuned to the delicate chemistry of their environment, even minor changes can cause severe disruptions.

Impacts on Antarctic Marine Life

Marine organisms, particularly those that rely on calcium carbonate to build shells and skeletons, face immediate danger as ocean acidity rises. These organisms, like pteropods (tiny marine snails), find it increasingly difficult to extract calcium carbonate from the water. As a result, their shells may dissolve or become thinner, forcing them to expend more energy on shell maintenance rather than other vital functions like reproduction and feeding.

Furthermore, rising acidity doesn’t just affect shelled creatures. Studies on Antarctic krill, a cornerstone of the Antarctic food web, have shown that their metabolism increases in more acidic conditions, making them more vulnerable to stress. Other species, such as dragonfish, suffer developmental harm when exposed to both warmer temperatures and more acidic waters.

“We know that ocean acidification is a significant stressor,” said Cara Nissen, a co-author of the study and an ocean biochemist at the University of Colorado Boulder. “And we know that the organisms care about it.”

The study, which utilized high-resolution models to predict changes in acidity levels across different scenarios, presents a stark warning. In the most aggressive global warming scenario, the pH in the waters around Antarctica could drop by 0.36, more than triple the decline seen since the Industrial Revolution. Even under less severe emission scenarios, the acidity of these waters is expected to rise by 40% to 80%.

The threat is especially pronounced in areas where cold, dense water sinks to the ocean floor. This process brings acidic water to the depths where many marine organisms live, subjecting them to a hostile environment. Additionally, melting ice introduces fresh water with less buffering capacity than seawater, amplifying the impact of carbon absorption.

No Safe Haven 

Previously, some scientists believed that Antarctica’s remoteness and icy waters might protect it from the worst effects of ocean acidification. However, the study’s findings indicate that these waters are just as vulnerable as any other region on Earth. The rapid rate of acidification could outpace the ability of marine organisms to adapt.

Clara Manno, a marine ecologist with the British Antarctic Survey, emphasized that no region is safe from ocean acidification. “Remote waters are not a way to escape,” she said. “It’s everywhere.”

The speed of acidification is also a critical concern. Fast-rising acidity levels leave organisms with little time to adjust, increasing the likelihood of widespread ecological disruptions.

Protecting Antarctic Ecosystems

Given the dire projections, the need to curb global carbon emissions is more urgent than ever. Keeping emissions low is critical to mitigating the worst effects of ocean acidification. Additionally, reducing other human-induced stressors on marine life, such as overfishing and pollution, could help fragile ecosystems better withstand rising acidity.

One proposed solution is the expansion of Marine Protected Areas (MPAs) around Antarctica. MPAs are regions where human activities like fishing are restricted, providing a sanctuary for marine organisms. Protecting these areas could give Antarctic ecosystems a fighting chance to adapt to the changing environment.

“It’s all about reducing the stress on these ecosystems as much as possible,” Nissen said. While these efforts may not stop the rise in acidity entirely, they could provide the resilience necessary for some species to survive.

 As the world continues to emit carbon dioxide, the Southern Ocean will become increasingly hostile to the creatures that call it home. Immediate action, both in terms of reducing emissions and protecting vulnerable ecosystems, is crucial to safeguarding one of the world’s last great wildernesses from the ravages of ocean acidification.