Science. Atmospheric acidity affects the ocean environment, according to new research

Madrid, 7 (European Press)

Increased acidity in the atmosphere is altering the ecological balance of the oceans, according to new research led by the University of East Anglia (UEA), UK, and published in the journal Science Advances.

The first study to analyze the effect of acidity on nutrient transport to the ocean shows that the way nutrients are supplied affects the ocean’s productivity and ability to absorb carbon dioxide from the atmosphere.

The research was conducted by an international team of experts, sponsored by the United Nations Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP).

Professor Alex Baker, Professor of Marine and Atmospheric Chemistry in the School of Environmental Sciences at the University of East Anglia and lead author, explains that “Human emissions of pollutants have caused significant changes in the acidity of the atmosphere, resulting in effects on known environmental conditions, such as acid rain. The acidity of the atmosphere affects The atmosphere affects the amount and distribution of nutrients (nitrogen, phosphorous and iron) that reach the ocean.”

As noted, “acids attack the surface of desert dust particles when they are carried by the atmosphere, increasing the proportion of phosphorous and iron present in these particles that will dissolve when the dust falls into the ocean.”

“Our work indicates that the increase in acidity since the Industrial Revolution has increased soluble phosphorous and iron by 14% and 16%, respectively – he continues – these increases will have a direct fertilizing effect on marine phytoplankton.”

Over the same time period, pollutant emissions have at least doubled the amount of nitrogen added to the oceans through the atmosphere.

Professor Maria Kanakido of the University of Crete in Greece also contributed to the research using global models of chemical transport deposition. According to her, “Acidity controls the distribution of oceans through the atmosphere. Acidity controls the distribution of nitrogen between molecules and gases in the atmosphere, so changes in acidity alter the length of time that nitrogen remains in the atmosphere and, therefore, where it is present Atmospheric nitrogen. The ocean will be deposited.”

In addition to fertilization, these changes in the quantity and geographical distribution of nutrient deposition also affect the ecological balance of the oceans.

Professor Kanakido points out that “Phytoplankton communities are sensitive to the ratios of nutrients available to them. The changes in nutrient deposition we identified may have caused ecological changes, because atmospheric inputs alter the nutrient balance in the water. They are superficial.”

He adds that these changes could favor certain types of phytoplankton over others, depending on the adaptation of organisms to the relative levels of nutrients in the water.

Professor Athanasios Nenes, of the EPFL in Lausanne (Switzerland) and the Center for Studies on Air Quality and Climate Change of the Foundation for Research and Technology in Hellas (Greece), explains that “fine particles in aerosols tend to remain strongly acidic, despite the reductions It is only thanks to advances in theory and modeling that understanding this irrational behavior and its impact on ocean nutrient supply has only been possible.”

According to the alert, “anthropogenic emissions will continue to modify the acidity of the atmosphere in the future. Emission controls in place to deal with acid rain will reduce the acidity of aerosols in many regions of the world, while continued economic development is likely to increase acidity in others.” “.

The researchers consider the system unlikely to return to its pre-industrial state, since wildfires – which affect both nutrient supply and acidity – will play a larger role in a warmer climate and their impact is highly uncertain.

In this regard, Professor Baker stresses that “Knowledge of the complex interactions between nutrient supplies and marine microbial communities is limited. Predictions about the consequences of long-term changes in atmospheric acidity in marine ecosystems will need to be considered in combination with other system stressors, such as ocean acidification, warming and deoxygenation.” “.