Answer:There has been a 30% increase in the average acidity of surface ocean water.
Explanation: According to the National Oceanic and Atmospheric Administration(NOAA), Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent.
This increase is the result emission of more carbon dioxide into the atmosphere due to human activities eg industrial activities leading to more carbon dioxide being absorbed into atmosphere which in turn leads to formation of acid rain and a resulting effect on the oceans( water body) which is posing a threat to aquatic life.