From Smokestacks to Seashells

carbon dioxide (CO,) FROM SMOKESTACKS TO SEASHELLS OCEAN ACIDIFICATION takes place when the ocean absorbs carbon dioxide from the atmosphere, making the ocean more acidic (lowering the pH, the measure of acidity). Scientists estimate that the average pH of surface waters of the ocean has fallen by about 0.1 pH unit since the Industrial Revolution and will continue to fall in the future. Since the pH scale is logarithmic, a 0.1 unit pH drop means about 30 percent increase in the ocean hydrogen ion concentration [H+] and therefore a large increase in acidity. runoff A small decrease in pH means many more hydrogen ions. INCREASED CO, DECREASE OF 0.1 pH = 30% INCREASE IN HYDROGEN IONS [H+] 2, This has three major negative effects: H+ "TUG OF WAR" "KRYPTONITE" H+ H+ "BOXING MATCH" H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ Vs H+ H+ H+ CARBONATE H+ H H+ H+ H+ H+ H+ H+ (CO, ) H+ H+ 3 H+ H+ The growing army of hydrogen ions are battling marine organisms for valuable carbonate-an essen- tial building block for shell and structure formation. Without available carbonate, some organisms The increasing hydrogen ions are dissolving the shells and structures of some marine organisms, More hydrogen ions in the water means organisms have to actively fight to keep it out of their systems. This diverts energy from growth and reproduction, making critters weaker and weakening them. cannot grow strong shells. more vulnerable. FOR MORE INFORMATION, CONTACT JULIA ROBERSON | [email protected] Ocean Conservancy