Temporal variation in the taxonomic structure of microphytobenthos (MPB) in a riverine mangrove ecosystem was studied along the southwest coast of India. About 122 species of microphytobenthos comprising diatoms (113 species), cyanobacteria (seven species), dinoflagellate (one species), and euglenophyte (one species) were observed, in which pennate diatoms dominated by 92%. Major subclasses of diatoms identified were Bacillariophycidae, Fragilariophycidae, Thalassiosirophycidae, Melosirophycidae, and Coscinodiscophycidae. Average levels of fluvial nutrients estimated in the porewater were NO₃–N (28 ± 19.7 µmol L⁻¹), PO₄–P (3.77 ± 4.6 µmol L⁻¹), and SiO₄–Si (33.12 ± 27.2 µmol L⁻¹). The colonization and persistence of dense cyanobacterial mats during monsoon resulted in less abundance and diversity of diatoms than in other seasons. The numerical abundance of MPB was at its maximum during July (monsoon season) due to the dense cyanobacterial mat formed by Oscillatoria princeps. MPB diversity was at its maximum during MON (H´- 3.2), followed by POM (H´- 3.08) and lowest during PRM (H´- 2.23). The statistically significant seasonal variations in the diversity of MPB were noticed during the study period (ANOVA F value 8.120; df 2; p value < 0.05). The present study identifies sediment temperature and porewater salinity (freshwater preference) along with rainfall, sediment pH and C:N ratio as the major governing factors in the benthic microalgal mat formation of the study area.

研究了印度西南海岸河流红树林生态系统中微型底栖植物（MPB）分类结构的时间变化。底栖微植物约122种，包括硅藻(113种)、蓝藻(7种)、甲藻(1种)、裸藻(1种)，其中羽状硅藻占92%。已鉴定的硅藻主要亚类为 Bacillariophycidae、Fragilariophycidae、Thalassiosirophycidae、Melosirophycidae 和 Coscinodiscophycidae。孔隙水中河流营养盐的平均水平估计为NO ₃ –N (28 ± 19.7 µmol L ⁻¹ )、PO ₄ –P (3.77 ± 4.6 µmol L ⁻¹ ) 和 SiO ₄ –Si (33.12 ± 27.2 µmol L −1 ) ^{。 1}）。季风期间密集的蓝藻垫的定殖和持续存在导致硅藻的丰度和多样性低于其他季节。由于颤藻形成的致密蓝藻垫，MPB 的数量丰度在 7 月（季风季节）达到最大值。MPB 多样性在 MON 期间达到最大 (H´- 3.2)，其次是 POM (H´- 3.08)，在 PRM 期间最低 (H´- 2.23)。在研究期间，注意到 MPB 多样性存在统计学上显着的季节性变化（方差分析F值 8.120；df 2；p值 < 0.05）。本研究确定沉积物温度和孔隙水盐度（淡水偏好）以及降雨量、沉积物 pH 值和 C:N 比是研究区域底栖微藻垫形成的主要控制因素。