High-resolution record of surface seawater CO2 content from December 2014 to April 2016 collected in Hyacinthe Bay, British Columbia, Canada. Version 1.0.

Quadra Island, at the northern terminus of the Salish Sea, has been a site for shore-based and high-resolution measurement of surface seawater CO2 content since December 2014. Measurements of in situ temperature, salinity, and CO2 partial pressure are made near-continuously from a seawater sample line with an intake 50 m from shore and at a depth of 1 m in Hyacinthe Bay on the eastern side of Quadra Island. The effort to collect these data are part of the Hakai Institute’s directive to advance the understanding of carbon cycling in northeast Pacific coastal settings with specific emphasis on sea-air CO2 exchange and ocean acidification.