Our oceans are becoming more and more acidic, which is just plain terrible for the Earth’s ecosystem. Photo: Unsplash
The Earth’s ecosystem is a finely balanced thing. Everything relies on the health of everything else, and we’re quickly throwing that balance out of whack. One of the most important indicators of the overall health of the planet is the acidity of the ocean, and a new study found that ocean acidity is rising, and rising quickly to dangerous levels. NOAA describes ocean acidification as “a reduction in the pH of the ocean over an extended period of time, caused primarily by an uptake of carbon dioxide (CO2) from the atmosphere.”
The study, which was done by a team of American and UK researchers, looked at something called the planetary boundary for ocean acidification. That boundary is quantified as a 20 percent drop in the saturation of aragonite in the surface levels of the sea. Aragonite comes from the calcium carbonate that marine animals use to make their shells and skeletons. According to the study, “the average global ocean conditions had already crossed into the uncertainty range of the ocean acidification boundary” in 2020, and they’ve only gotten worse since.
“Ocean acidification has been identified in the Planetary Boundary Framework as a planetary process approaching a boundary that could lead to unacceptable environmental change,” the study’s abstract reads.
The researchers found that oceans around the world had either crossed that 20 percent boundary or were very close to it. Some 60 percent of deeper waters have gone beyond it, as well as 40 percent of surface waters.
“Looking across different areas of the world, the polar regions show the biggest changes in ocean acidification at the surface,” said biological oceanographer Helen Findlay from Plymouth Marine Laboratory (PML) in the UK. “Meanwhile, in deeper waters, the largest changes are happening in areas just outside the poles and in the upwelling regions along the west coast of North America and near the equator.”
Ocean acidification isn’t exactly something you’ll notice with the naked eye, but it has enormous consequences. Lower pH levels — more acidic — wrecks coral reefs, makes life almost impossible for anything that has a shell, and can kill all manner of marine life. Since the good health of everything on the Earth generally requires the good health of everything else, this is not a good thing.
According to Science Alert, “This acidification happens when carbon dioxide is absorbed by the ocean and reacts with water, and so the more greenhouse gases saturate the atmosphere, the more acidic the world’s waters are going to become.”
The vast majority of marine animals don’t live only on the surface, so the deeper waters becoming more acidic is cause for serious concern.
“Most ocean life doesn’t just live at the surface – the waters below are home to many more different types of plants and animals,” Findlay explained. “Since these deeper waters are changing so much, the impacts of ocean acidification could be far worse than we thought. This has huge implications for important underwater ecosystems like tropical, and even deep-sea coral reefs that provide essential habitats and nursing refuge for many species.”
There are nine agreed upon Planetary Boundaries, which is basically a way of measuring limits on the Earth’s systems required to self-regulate. If they’re crossed, we’ll be in truly uncharted territory. Those boundaries are climate change, ocean acidification, stratospheric ozone depletion, biogeochemical flows in the nitrogen cycle, excess global freshwater use, land system change, the erosion of biosphere integrity, chemical pollution, and atmospheric aerosol loading.
We’ve crossed six. If we have crossed the ocean acidification planetary boundary, the straits the planet is in become even more dire.
“Ocean acidification isn’t just an environmental crisis – it’s a ticking time bomb for marine ecosystems and coastal economies,” Steve Widdicombe, a professor from the Plymouth Marine Laboratory, told Science Alert. “From the coral reefs that support tourism to the shellfish industries that sustain coastal communities, we’re gambling with both biodiversity and billions in economic value every day that action is delayed.”
