Total suspended material dynamics in Segara Anakan Lagoon, Central Java

Since past century Segara Anakan Lagoon (SAL), a coastal lagoon fringed by the remaining mangrove forest in Southern Java, has received inputs from the sediment-laden rivers, mainly the Citanduy. Here, we report the dynamics of total suspended material (TSM) in the lagoon from our diel observations over lunar cycles at some key stations during rainy season (October 2008January 2009). The results showed that organic carbon (POC) and total nitrogen (PNtot) content of the TSM were spatially different. The highest concentration of POC and PNtot were observed in the western area of the lagoon where the input of the sediment-laden river, the Citanduy, is located. In contrast to the west, TSM in the eastern area had low concentration of POC and PNtot. The signature of δ 13 Corg showed that the western TSM was mostly consist of riverine and mangrove derived organic matter while the eastern TSM was almost consist of marine organic matter. We calculated that POC were exported to the Indian Ocean from the lagoon via the western outlet while the lagoon received POC from the Indian Ocean trough eastern outlet.