Due to human-made emissions, the CO2 content of the oceans has increased dramatically and is gradually acidifying the surface waters. To understand how ocean acidification is affecting large marine areas, scientists studied a 5,000 km long strip of ocean and developed a new way to simultaneously assess overall calcification rates of coral reefs and open sea plankton over a whole oceanic basin, based on variations in surface water chemistry. This is the first study that demonstrates the feasibility of quantifying this type of information on an oceanic basin scale....