Abstract:
Oceanographic cruises were conducted to investigate the dynamical relationship between
hydrography, current circulation and phytoplankton biomass at the east coast of
Peninsular Malaysia (ECPM) and elucidate the structure of upwelling at the ECPM
especially in the vicinity of Tioman Island. Physical observations in the upwelling area
were analysed with respect to local wind forcing. Chlorophyll a and nutrients
measurements were discussed based on different seasonal influence. In addition to field
data measurement, satellite images were used to demonstrate the presence of upwelling
and examine the spatial patterns of phytoplankton biomass at the ECPM. The outcome of
this study showed that the southwesterly monsoon wind, which induced coastal
upwelling, was the major mechanism that shaped the hydrographic character and the
relatively high phytoplankton biomass found at the study area. Results also showed that
the waters off Tioman Island had relatively cooler temperature and higher phytoplankton
biomass due to nutrient enhancement than Terengganu. The presence of this character
was in response to strong northward upwelling and freshwater intrusion in both areas. In
the vicinity of Tioman Island, there was a small but distinguishable cooler-upwelled water and slightly stronger current at the north of the island. This feature appeared to be
caused by the interaction of multiple dynamical processes including coastal upwelling,
island circulation and topographic variations in this area. Overall, the interaction of
physical processes between wind-induced upwelling, coastal current and island
circulation were believed to be the key drivers in regulating the hydrography and
horizontal as well as vertical distribution of phytoplankton biomass.
