Phosphorus Fractionation and Its Bioavailability in Panjang Island Jepara

Abstract

Panjang Island waters located in Jepara Regency. It has rich diversities of aquatic ecosystems. Panjang Island close to the estuary of Wiso and Sampok River. Nutrient inputs from river to marine waters including phosphorus (P) affect primary productivity. A productive ecosystem is essential for nursery ground and coastal fisheries sustainability. The purposes of this research are to know the value of concentration and distribution of dissolved inorganic phosphate (DIP), the concentration of phosphorus fraction in sediment (Ads-P, Fe-P, Ca-P, TIP, Org-P, Total P) and their bioavailability. The concentration of dissolved inorganic phosphate in the water column shows different patterns where at 0.2 d; 0.6 d; 0.8 d the concentration value ranged between 0.010 μmol/l and 0.022 μmol/l; 0.005 μmol/l and 0.021 μmol/l; 0.010 μmol/l and 0.043 μmol/l. Inorganic phosphate concentrations in the sediment are larger than organic phosphates. The most abundant inorganic phosphate fraction of concentration is Ca-P. The relative abundance for inorganic phosphates follows the order of Ca-P> Fe-P> Ads-P. Concentrations of phosphate fraction in sediment for Ads-P, Fe-P, Ca-P, TIP, Org-P ranged between 0.05 and 0.30 μmol/g; 0.66 and 4.11 μmol/g; 2.9 μmol/g and 7.97 μmol/g; 3.69 and 12.48 μmol/g; 0.49 and 4.55 μmol/g. Total P (TP) has a concentration ranged between 5.13 μmol/g and 13.34 μmol/g. The potential of bioavailability of P (BAP) is 17.5 -53.5% of TP. The concentration and the availability of P in the Panjang Island waters are influenced by various factors such as ocean current and sediment grain size.