Few studies have investigated the effect of fine-scale habitat differences on the dynamics of benthic harmful dinoflagellate assemblages. To determine how these microhabitat differences affect the distribution and abundance of the major benthic harmful dinoflagellate genera in a tropical coral reef ecosystem, a field study was undertaken between April–September 2015 and January 2016 on the shallow reef flat of the fringing reef of Rawa Island, Terengganu, Malaysia. Sampling of benthic dinoflagellates was carried out using an artificial substrate sampling method (fiberglass screens). Benthic microhabitats surrounding the sampling screens were characterized simultaneously from photographs of a 0.25-m² quadrat based on categories of bottom substrate types. Five taxonomic groups of benthic dinoflagellates, Ostreopsis, Gambierdiscus, Prorocentrum, Amphidinium, and Coolia were identified, and cells were enumerated using a light microscope. The results showed Gambierdiscus was less abundant than other genera throughout the study period, with maximum abundance of 1.2 × 10³ cells 100 cm⁻². While most taxa were present on reefs with high coral cover, higher cell abundances were observed in reefs with high turf algal cover and coral rubble, with the exception of Ostreopsis, where the abundance reached a maximum of 3.4 × 10⁴ cells 100 cm⁻² in habitats with high coral cover. Microhabitat heterogeneity was identified as a key factor governing the benthic harmful dinoflagellate assemblages and may account for much of the observed variability in dominant taxa. This finding has significant implications for the role of variability in the benthic harmful algal bloom (BHAB) outbreaks and the potential in identifying BHAB-related toxin transfer pathways and the key vectors in the food webs.

很少有研究调查过细微的生境差异对底栖有害鞭毛藻群落动态的影响。为了确定这些微生境差异如何影响热带珊瑚礁生态系统中主要底栖有害双鞭毛藻属的分布和丰度，于2015年4月至2016年9月至2016年1月之间，在拉瓦岛边缘礁的浅礁滩上进行了实地研究。 ，马来西亚登嘉楼。使用人工基质采样方法（玻璃纤维筛网）对底栖鞭毛藻进行采样。基于底部基质类型的类别，同时从0.25-m ²正方形的照片同时表征了采样屏幕周围的底栖微生境。底栖鞭毛藻的五类分类，鉴定了骨增生症，冈比亚菌，原肠，两栖动物和库里亚，并使用光学显微镜对细胞进行计数。结果显示，在整个研究期间，甘比氏菌的丰度不如其他属，最大丰度为1.2×10 ^3个细胞100 cm ^-2。尽管大多数分类群都存在于珊瑚覆盖率较高的礁石上，但在草皮藻覆盖率较高且珊瑚碎屑较多的礁石中观察到较高的细胞丰度，除了骨Ost鱼（Ostreopsis）外，其丰度最大为3.4×10 ^4个细胞100 cm ^-2在高珊瑚覆盖的栖息地。微生境的异质性被认为是控制底栖有害鞭毛藻组合的关键因素，可能解释了主要分类群中观察到的大部分变异性。该发现对底栖有害藻华（BHAB）暴发中的可变性作用以及识别食物链中与BHAB相关的毒素转移途径和关键载体的潜力具有重要意义。