Fluks CO2 di Perairan Pesisir Pulau Lombok, Nusa Tenggara Barat

Abstract

<strong>CO<sub>2</sub> Flux in the Coastal Waters of Lombok, West Nusa Tenggara.</strong> Coastal and marine areas play an important role in climate regulation by absorbing CO<sub>2</sub> and exchanging carbon with various carbon storing compartments as the atmosphere, land and biota. This study aims to determine the exchange of CO2 between the sea surface to the atmosphere in the coastal waters of the island of Lombok and its components sink and source, and to know the parameters that influence the process. Field observation was carried out during April, 2012 in Sekotong Bay (10 Stations) and Kodek Bay (6 Stations).The partial pressure of CO<sub>2</sub> (pCO<sub>2</sub>) in sea surface level, was calculated using ABIOTIC model of the ocean carbon cycle model intercomparison project phase-2 (OCMIP-2). The results showed that generally Kodek Bay waters and outside of Sekotong Bay act as a sink of CO2 from the atmosphere, while inside of Sekotong Bay act as source of CO<sub>2</sub> to the atmosphere.CO<sub>2</sub> flux in Sekotong bay waters and Kodek bay waters each ranging between -0.61 to 0.52 and -0.80 to -1.84 mmol.m<sup>-2</sup>.d<sup>-1</sup> with an average of 0.05 ± 0.40 and -1.29 ± 0.40 mmol.m<sup>-2</sup>.d<sup>-1</sup>. Kodek Bay act as CO<sub>2</sub> sink because influence by water mass from Lombok Strait that have high concentrations of nutrient and chlorophyll. The existence of seagrass and coral reefs that support small islands in the Kodek bay helped reduce elevated pCO<sub>2</sub> water column and strengthen the absorption of CO<sub>2</sub> in these waters. Sekotong bay inside, acts as a release of CO<sub>2</sub>, because the waters of the Sekotong bay tend to be closed, so that the residence time of water masses becomes longer resulting in enrichment of DIC and pCO<sub>2</sub>.