CORAL-REEF ECOSYSTEMS AS A SOURCE OF ATMOSPHERIC CO2 - EVIDENCE FROM PCO2 MEASUREMENTS OF SURFACE WATERS

Precise measurements of the partial pressure of CO2 (PCO2) in oceanic and lagoonal surface waters from Palau Barrier Reef and Majuro Atoll w ere taken to ascertain the net effect of these coral reef systems on a ir-sea CO2 exchange. PCO2 in the surface water in the lagoon of Palau Barrier Reef and Majuro Atoll was 48 and 14 mu atm higher than in the surrounding oceanic water, respectively. A total carbon dioxide vs. to tal alkalinity diagram indicates that calcification is mainly responsi ble for CO2 evasion in these coral reef systems.