The physical and chemical characteristics of the environment in Singapore Straits are
described. Mention is also made of the currents and drift throughout the year. The
general distribution, both qualitative and quantitative, of the phytoplankton and zooplankton
is given. At the same time the main genera of phytoplankton which contribute
to the phytoplankton calender are highlighted. The interrelationships between phytoplankton,
zooplankton and fish in Singapore Straits are briefly discussed.