Carbon Dioxide Flux and its Relationship to Water Quality in the Teluk Awur - Jepara, Indonesia

Anthropogenic activities on land will affect the carbon system in coastal waters. This condition will affect the role of coastal waters as a source or sink of carbon. This research will examine the distribution of carbonate systems and estimate CO₂ fluxes. Water samples were taken at 30 stations as well as measuring in situ water parameters including pH, temperature, salinity, and pressure. Alkalinity was analysed based on the titration method, chl-a using the fluorometer method, and carbonate system parameters (pCO2(sea) and DIC) calculated using CO₂SYS.xlsm. The pCO2(atm) value is calculated based on atmospheric data from satellite data, including the saturation vapour pressure of sea air in the atmosphere, fraction mol of CO₂, and sea level pressure. Pearson correlation analysis was used to see the correlation between the measured parameters and CO₂ flux. Carbon flux is determined based on the difference between atmospheric and oceanic pCO₂. The DIC calculation result was in the range of 1,946.09 µmol/kg - 2,061.65 µmol/kg and the total alkalinity was 2,156.86 µmol/kg - 2,264.71 µmol/kg. Based on this value, Jepara coastal waters have pCO2(sea) of 573,800 micro-atmospheric (µatm) which is higher than pCO2(atm) (i.e., 386,772 µatm). The input of organic/inorganic carbon resulting from anthropogenic processes on land has influenced Jepara coastal waters which act as a source of CO₂ into the atmosphere amounting to 103,799 mmol/m²/day. The results of this research can be used as a reference for managing coastal areas to achieve low carbon emissions.