The composition and distribution pattern of diatom assemblages in the surface sediments of Sharm Al-Kharrar and Al-Shuaiba lagoons, situated on the central part of the Red Sea coastline of Saudi Arabia, were analyzed. A total of 191 diatom species from 53 genera were identified. A highly diverse diatom flora dominated by the genera Mastogolia, Amphora sensu lato, Lyrella, and Navicula sensu lato species was observed. Diatom species composition showed the dominance of the benthic forms over the epiphytic and planktonic ones, which can be attributed to the shallowness of the environments. The relationship between the recognized diatom taxa and measured environmental variables was explored using multivariate statistical techniques. Hierarchical ascending clustering and detrended correspondence analyses differentiated six representative diatom assemblages in each Lagoon. Canonical correspondence analysis revealed that grain size, organic matter content, and water depth appeared to be significant environmental factors affecting the distribution and structure of the documented diatom assemblages, while pH, salinity, and temperature were less influential. The majority of species recorded were polyhalobous benthic diatoms, accompanied by a limited abundance of mesohalobous and substantial amounts of oligohalobous forms, which are probably of allochthonous origin and resulting from freshwater input of near seasonal wadi streams and human activities. A comparison between the recognized diatom assemblages and the previously recorded taxa in surrounding areas was made.

分析了位于沙特阿拉伯红海海岸线中部的沙姆沙伊尔-哈拉尔泻湖和沙伊巴泻湖的表层沉积物中的硅藻组合物的组成和分布模式。共鉴定了来自53个属的191种硅藻。高度多样化的硅藻菌群由属为主Mastogolia，安芙兰意义上拉托，Lyrella，和舟形意义上拉托观察到物种。硅藻的种类组成表明，底栖形式比附生和浮游生物占优势，这可以归因于环境的浅薄。使用多元统计技术探讨了公认的硅藻类群与测得的环境变量之间的关系。分层升序聚类和去趋势对应分析在每个泻湖中区分了六个代表性的硅藻集合。典型的对应分析表明，晶粒大小，有机物含量和水深似乎是影响所记录的硅藻组合物的分布和结构的重要环境因素，而pH，盐度和温度的影响较小。记录的大多数物种是多齿底栖硅藻，伴随着数量有限的中卤和大量的寡卤形式，这些形态可能是异源的，并且是由于近季节性旱谷流和人类活动所产生的淡水所致。在周围地区，将公认的硅藻组合与先前记录的分类单元进行了比较。