Integrated monitoring system for coral reef water pCO2, carbonate system and physical parameters

Abstract

To monitor changes in reef water carbonate system in response to community metabolism and global change, an integrated monitoring system for pCO2, total alkalinity (TA), total inorganic carbon (TIC) and related physical parameters was developed. The system was loaded on a small boat and run with minimum maintenance. The continuous (on-line and flow-through) TA and TIC monitoring system was also loaded and operated by supplying standard solutions daily. The pCO2 values between a flow-through type and a membrane type equilibrators matched within 6 µatm. The TA and TIC values by the continuous system matched with those by a precision analyzer with a deviation of 10 µmol kg -1 . The monitoring results showed that pCO2, TA, TIC, temperature, dissolved oxygen (DO) and pH in coral reef water changed diurnally by photosynthesis and calcification during the day and respiration at night. The system succeeded in monitoring short-term TA and TIC spike corresponding to the other chemical and physical parameters, which were difficult to observe by discrete manual water sampling. These synchronicities validate the performance of this integrated system. This system can be applied to coastal zone monitoring, buoy system and laboratory aquarium experiment in general.