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.
