Ocean Acidification is Dissolving Starfish

Although warming water temperatures get much of the negative press when it comes to our oceans, ocean acidification is wreaking havoc as well.

Most divers know that waters are warming around the world, and this is leading to all manner of negative impacts for the oceans. But ocean acidification could present just as large a threat.

Threats from ocean acidification

Researchers from Heriot-Watt University in Edinburgh and Glasgow University have discovered that high levels of carbon dioxide in the water are literally dissolving sea creatures. The team of marine scientists conducted a four-day experiment in Loch Sween in Scotland. There, they measured the effect of high levels of carbon dioxide in the water, which is the main driver of ocean acidification. The team pumped water that had been enriched with carbon dioxide into chambers placed over a coralline algal ecosystem and monitored the community’s response before, during and after exposure. The experiment proved that acute exposure led to “net dissolution,” which means calcified organisms, such as the coralline algae and starfish, were dissolving.

“We found that there was a rapid, community-level shift to net dissolution, meaning that within that community, the skeletons of calcifying organisms like starfish and coralline algae were dissolving,” said Heidi Burdett, Heriot-Watt University research fellow to Metro UK.

“If you think of pulses of carbon dioxide being carried on the tide to a particular site, it’s like a flash flood of carbon dioxide. Our continued monitoring of the site directly after the carbon dioxide exposure found recovery was comparably slow, which raises concern about the ability of these systems to ‘bounce back’ after repeated acute carbon dioxide events.”

Scientists around the world share this fear that sustained high levels of carbon dioxide in the water will cause irreparable damage to marine ecosystems. Burdett and the other researchers think more research is necessary, but that policymakers must take carbon dioxide levels into account when determining the future of the oceans. “If a local authority or government agency is deciding the location of a new fish farm, forestry or carbon capture site, we should be looking at what marine ecosystems are nearby, and the potential for those ecosystems to be impacted by the new activities as a whole, rather than focusing on the impact on individual organisms,” she said to Metro UK.