Researchers at the University of Adelaide have been studying underwater volcanic vents to see what kind of effects excess CO2 has on ocean ecologies. Human activity has severely increased the amount of CO2 in the atmosphere, which in turn increases the amount of CO2 in the oceans, as they absorb a significant amount of that CO2. Unfortunately, the oceans can only absorb so much before it starts the have a side effect, which is already is. All that CO2 is making the oceans more acidic, and that’s bad. In fact, if things keep going the way they are, by the end of the century ocean acidification will have increased so much that most temperate ecosystems will have been devastated.

Ocean Acidification

The vents in question dump out an amount of CO2 into the surrounding water that equates to the projected levels at the end of the 21st century, giving the researchers a sort of natural laboratory in which to study ocean acidification. Those regions, when compared to neighboring ecosystems with “normal” levels of CO2, have much less biodiversity. They are dominated by fewer, more robust species of fish that rise to dominance at the expense of other species, and they lack kelp forests, home instead to short turf algae.

The researchers discovered that many fish have reduced responses to predators while in more acidic water, meaning that they have a harder time escaping, making them easy prey for invasive species. This problem wasn’t as bad when they were already close to safety, but with less vegetation, there are less places to hide. Invasive species which can survive in more acidic water, like gobie and triplefin, will likely devastate indigenous fish species as their ecosystems shift radically.

The research gives us a clearer picture of what is in store, allowing us to hopefully combat ocean acidification before it gets too bad, and to find ways to mange natural and managed ecosystems before they collapse.