The tropical climate is seemingly stable with little variation in environmental factors throughout the year. However, a growing number of studies have reported monsoon-driven changes in zooplankton communities in tropical waters. This study examined the monsoonal and spatial variation in the zooplankton community in Sepanggar Bay, Malaysia. Samples were collected from 9 stations throughout the bay in June and October 2017, March and June 2018, coinciding with the southwest monsoon (SWM), northeast monsoon (NEM) and the intermonsoon periods (INTER). Significant seasonal difference was observed for the measured hydrographic parameters (chlorophyll-a, salinity, temperature) with highest values recorded during INTER for chlorophyll-a, NEM for salinity, and SWM 2 for temperature. Throughout the study, 110 zooplankton taxa were identified, and copepods dominated total zooplankton abundance by 70%. Zooplankton abundance increased from 17925 ± 8616 inds. ${\mathrm{m}}^{-3}$ during SWM 1 to peak at 47628 ± 55488 inds. ${\mathrm{m}}^{-3}$ during INTER and reached a minimum of (16136 ± 22334 inds. ${\mathrm{m}}^{-3}$ during NEM. Zooplankton abundances were relatively higher at nearshore stations compared with offshore stations, but was not statistically significant. Four distinct assemblages were obtained from Hierarchical Cluster analysis (HCA), suggesting the influence of monsoon in shaping the zooplankton community. The dominant zooplankton shifted from copepods during SWM1, INTER, and NEM, to tintinnids during SWM 2. Canonical Correspondence Analysis (CCA) revealed temperature and salinity to be strongly associated with zooplankton community, indicating seasonal variations in these environmental factors driven by monsoon which influenced the zooplankton community structure in the bay. Distinct shifts in the zooplankton composition and abundance relative to the monsoon seasons provide new insights into the seasonal sensitivity of zooplankton in tropical coastal ecosystems.

热带气候看似稳定，全年环境因素变化不大。然而，越来越多的研究报告了热带水域浮游动物群落的季风驱动变化。本研究调查了马来西亚雪邦加湾浮游动物群落的季风和空间变化。在 2017 年 6 月和 10 月、2018 年 3 月和 6 月，与西南季风 (SWM)、东北季风 (NEM) 和季风间期 (INTER) 相吻合，从整个海湾的 9 个站点收集了样本。测量的水文参数（叶绿素a、盐度、温度）观察到显着的季节性差异，在 INTER 期间记录的叶绿素a 的最高值，NEM 表示盐度，SWM 2 表示温度。在整个研究过程中，确定了 110 个浮游动物分类群，桡足类占浮游动物总丰度的 70%。浮游动物丰度从 17925 ± 8616 增加。 ${\mathrm{米}}^{-3}$ SWM 1 期间达到峰值 47628 ± 55488 inds。 ${\mathrm{米}}^{-3}$ 在 INTER 期间并达到最低 (16136 ± 22334 ind. ${\mathrm{米}}^{-3}$在 NEM 期间。与近海站相比，近岸站的浮游动物丰度相对较高，但没有统计学意义。从层次聚类分析 (HCA) 中获得了四种不同的组合，表明季风对浮游动物群落的影响。主要浮游动物在 SWM1、INTER 和 NEM 期间从桡足类转变为 SWM 2 期间的丁丁类。典型对应分析 (CCA) 显示温度和盐度与浮游动物群落密切相关，表明这些环境因素的季节性变化受季风驱动，影响海湾中的浮游动物群落结构。