TITLE:
Distribution Pattern of Dissolved Inorganic Nutrients and Phytoplankton Diversity in River Estuary, Kota Kinabalu Sabah, Malaysia
AUTHORS:
Sujjat Al Azad, Jiney Liow Fui San, Ejria Saleh
KEYWORDS:
River Estuary, Nutrients, Phytoplankton Abundance, Diversity and Evenness
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.10 No.8,
August
30,
2022
ABSTRACT: Nutrients are influenced by anthropogenic activities and consequently
change the diversity and density of phytoplankton. The
spatial distribution of dissolved inorganic nutrients and phytoplankton
diversity and density were determined in river estuary, Kota Kinabalu, Sabah,
Malaysia. Samples of water and phytoplankton
were collected from six locations of river estuary during the month of
May 2019 to October 2019. The highest abundances of 86% diatoms were determined
during the study period. This was followed by 13% and 1% of dinoflagellates and
Cyanobacteria respectively. The most dominance species of Skeletonema costatum, with density of 1186.69 × 103 cells/L and Thalassiosira sp. (938.01 ×103 cells/L) were recorded from
Station 1 (upstream) and Station 5 (mangrove area) respectively. The Chaetoceros sp. (84.25 × 103 cells/L) was the dominated in Station 6 (control site). Station 4 (residential area)
accounted the highest diversity of species such as Skeletonema costatum, Thalassiosira sp., Peridinium sp., Gonyaulax sp., and Cylindrotheca sp. with total cell density of 142.98 × 103 cells/L.
The high diversity index of 5.2 to 7.09 and evenness index of 1.81 to 2.87 were
determined from this river estuary. Very poor relationship was observed with
the cell density and dissolved inorganic nutrients, phosphate (R2 = 0.2437),
ammonium (R2 = 0.301) and nitrate (R2 = 0.406).
The diversity and abundance of phytoplankton in this river estuary not only
depend on nutrients, but might be
associated with other environmental factors, tidal fluctuations and rate of
discharge of nutrient inputs from surrounding areas. This study suggests
that long term monitoring not only the nutrients, but discharges and flushing
of nutrient during rainfall and tidal fluctuation together with environmental
factors should be considered in order to conclude status on the diversity and
abundance of phytoplankton in river estuary.