delware environmental institute

Shipping pollution: Emissions from shipping making ocean more acidic, researchers report

Shipping pollution: Emissions from shipping making ocean more acidic, researchers report

Shipping pollution along major trade lanes can rival carbon emissions in contributing to the increased acidity of the ocean, according to a new study by an international team, including researchers from the University of Gothenburg, Chalmers University of Technology, the University of Delaware and the Institute for Advanced Sustainability Studies. The research is the first global analysis that shows that acidification from shipping can during the summer months equal that from carbon dioxide. 

Rising levels of carbon dioxide in the atmosphere cause a steady acidification of the ocean as carbon dioxide dissolves into the water and produces the weak acid carbonic acid. Other gases can also cause acidification, for example sulfur and nitrogen oxides, which dissolve to give the strong acids sulfuric acid and nitric acid respectively.

“These oxides are present in the exhaust gases from ships’ engines,” said David R. Turner of the University of Gothenburg in Sweden. “Sulfur oxides come from the sulfur present in marine fuel oil, while nitrogen oxides are formed from atmospheric nitrogen during combustion. Emission of these oxides causes atmospheric pollution, followed by marine pollution (acidification) on deposition.”

Ocean acidification has been shown to harm the health of coral, squid, mussels and other sea life.