Abundance and composition of zooplankton in the Straits of Malacca

The zooplankton composition and distribution were studied during four oceanographic cruises in the Straits of Malacca between November 1998 and August 2000 with 140 mu m-mesh and 45-cm diameter NORPAC net. Zooplankton samples were analyzed for the faunal composition and abundance. Zooplankton abundance peaked during pre-southwest monsoon (mean of 12, 918 +/- 5, 635 ind. m(3)). Copepods were the most important constituents of the zooplankton in all areas. Copepods (including copepodites) accounted for 71.3%, 71.2%, 70.9% and 57.9% of the total zooplankton populations during consecutive cruises I, II, III and IV, respectively. Molluscs (6.3% to 12.4%) and crustacean's nauplii (4.4% to 6.0%) comprised the important groups of non-copepod zooplankton. Spatio-temporal variation in zooplankton abundance was not statistically significant. Zooplankton was more abundant in the near-coastal areas than in offshore areas, but the difference was not significant.