Munida Transect Ocean Carbon data

The ‘Munida transect’ Time-series in sub-antarctic waters off Otago is the Southern Hemisphere’s longest-running record of pH measurements. Monitoring since 1998 has established a decline in pH that reflects the increase in atmospheric CO2 recorded at NIWA’s atmospheric research station near Wellington. Water samples were collected every two months along a 65-kilometre line from the tip of Otago Harbour out to sub-antarctic waters. Data collected include pH, alkalinity, total dissolved inorganic carbon and CO2 as well as other related parameters. The supporting data help to determine what processes are causing changes in the properties of the water masses, including the changes in pH. For example, pH is linked to temperature and therefore varies between summer and winter and also year to year.

The data is made available here for download at no charge for non commercial use only.

If you need other data or licence arrangements, please lodge a request through data enquiries.