Dissolved and particulate phosphorus species partitioning and distribution in the Danshuei River Estuary, Northern Taiwan

Different phosphorus fractions, including total dissolved P (TDP), dissolved inorganic P (DIP), total particulate P (TPP), and particulate inorganic P (PIP), were analyzed in the Danshuei River Estuary (DRE), northern Taiwan to study the P partitioning within the estuary. Relatively higher concentrations of TDP (4.3-12.4 mu M) and TPP (2.3-8.7 mu M) were generally found in the upper estuary, salinity < 5 region, during the four surveys. The DIP concentration generally dominated the total P pool (TDP + TPP) within the estuary. However, dissolved organic P (DOP) became the important fraction in the salinity > 25 region, probably attributed to phytoplankton production because the higher DOP concentration was generally accompanied with a higher Chl. a concentration. The TPP concentrations generally correlated well with the total particulate Fe and Mn concentrations, suggesting that particulate Fe and Mn played crucial roles influencing the P distribution within the DRE.