Anthropogenic (human-caused) carbon dioxide emissions are taken out of the atmosphere by our oceans, increasing the availability of dissolved inorganic carbon which in turn, reduces both the carbonate saturation and pH of seawater.
The new study was undertaken by Jason M Hall-Spencer and Ro Allen, researchers at the Marine Biology and Ecology Research Centre, School of Marine Science and Engineering, Plymouth University, Plymouth, Devon, UK.
While acidification has had a destructive effect on corals and a number of other marine organisms, the study found a large number of “nuisance” marine organisms that actually are tolerant of acid conditions. Resilient and highly adaptable, these organisms are thriving in new locations, competing with native marine species.
“We are witnessing the spread of marine life that cause problems — such as toxic jellyfish blooms and rotting algal mats,” study lead author Jason Hall-Spencer said in a press release, reported by CBS News.
With rising carbon levels, the threat to indigenous species is real enough, says Hall-Spencer, and he says the health risks from the invasive organisms can spread to humans on land, as well. “Pathogens like cholera do not recognize national borders so seawater warming is a health issue for cities like London, and it remains to be seen which organisms will spread and cause problems as Arctic shipping routes open up,” he added.
Professor Hall-Spencer has been interested in what forms of sea life would do well in higher CO2 levels for a number of years. He has led expeditions to volcanic sites in the Mediterranean, recording his observations. What he learned led to this study.
Through laboratory experiments, organisms like “Killer algae” (Caulerpa taxifolia), which is spreading worldwide, Japanese kelp (Undaria pinnatifida) and stinging jellyfish (Pelagia noctiluca), were found to be far more tolerant of increasingly acidic seawater.
“Observations show there will be winners as well as losers as carbon dioxide levels ramp up, just as there were in previous mass extinctions,” Ro Allen, one of Hall-Spencer’s researchers said. “The spread of harmful marine organisms should be factored into risks of rising carbon dioxide emissions.”
The study, “The impact of CO2 emissions on ‘nuisance’ marine species,” was published in Research and Reports in Biodiversity Studies on November 5, 2015.
