text: In 2015, the United Nations adopted the 2030 Agenda and a set of 17 Sustainable Development Goals (SDG), including a goal dedicated to the ocean, Sustainable Development Goal 14, which calls to "conserve and sustainably use the oceans, seas and marine resources for sustainable development". Ocean acidification is directly addressed by the target SDG 14.3. The full title of Target 14.3 is: "Minimize and address the impacts of ocean acidification, including through enhanced scientific cooperation at all levels". This target has one indicator: Indicator 14.3.1 which calls for the "Average marine acidity (pH) measured at agreed suite of representative sampling stations". 
  The Intergovernmental Oceanographic Commission (IOC) of UNESCO was identified as the custodian agency for the SDG 14.3.1 Indicator. In this role, IOC-UNESCO is tasked with developing the SDG 14.3.1 Indicator Methodology, the annual collection of data towards the SDG 14.3.1 Indicator and the reporting of progress to the United Nations.