The IOC-UNESCO recently published a new book entitled: Oceanographic and biological features in the Canary Current Large Marine Ecosystem, edited by L. Valdés and I. Déniz-González. The book can be read in the next link ( book ). The chapter 6.5: Ocean Acidification in the Canary Current Large Marine Ecosystem, was written by J. Magdalena Santana-Casiano and M. González-Dávila, members of EACFe proyect. There, the authors presented the trend of pH in the European Station for Time series in the Ocean (ESTOC) located at 60 km North of Gran Canaria (29°10’N, 15°30’W). For more than 15 years, the QUIMA group has been measuring the pH in the water column in that station and the pH is decreasing (total scale) in 0.0019 ± 0.0003 units per year, with the increasing of the seawater partial pressure of CO2 of 1.9 ± 0.3 µatm yr -1 . The pH has a seasonal variability with variations between 0.03 - 0.05 pH units. The lowest values are observed during the winter due to t...