The Distributions And Behaviour Of Nitrogen-Based Nutrients In Terengganu River Estuary

Abstract

This study was carried out to determine the distribution and behaviour of nitrogen (N)-based nutrients for surface water in Terengganu River estuary (TRE). The N- based nutrients measured were dissolved inorganic N (nitrite, nitrate and ammonia) and organic N (dissolved organic nitrogen (DON) and particulate organic nitrogen (PON)). Surface water samples were collected during longitudinal and diurnal surveys under different tidal conditions from February to September 2012. Low concentration of nitrite (0.002-0.393 µM) and nitrate (0.3-4.7 µM) were found during longitudinal surveys. Meanwhile, the concentration of ammonia, DON and PON were 1.0-35.4 µM, 3.2-40.6 µM and 1.5-23.6 µM, respectively. The results also indicated that the percentage concentrations of dissolved inorganic N (longitudinal = 35%; diurnal = 19%) were lower than organic N (longitudinal = 65%; diurnal = 81%). Generally, distributions of N-based nutrients were higher in freshwater region which indicated a strong riverine influenced in TRE. In addition, most of N-based nutrients showed higher concentration during spring tide suggesting contribution from the resuspension of bottom sediments. Most of the parameters measured appear to behave non-conservatively with an addition tendency.