Current State of Microphytobenthos of the Red Sea

Microphytobenthos of the coastal waters of the Red Sea was investigated based on the results of sampling carried out over a long period of time (2006-2024). On the whole, 331 species of microscopic algae represented by 337 infraspecific taxa of 116 genera, 55 families, 33 orders, 6 classes, 3 divisions, 2 kingdoms, and 2 domains (empires) were identified. A characteristic feature of microphytobenthos of the Red Sea is the predominance of Hetero-kontophyta (304 species). Among the identified algae, 11 new species were recorded for the Red Sea water area. They included Lyngbya aestuarii Liebman ex Gomont, Achnanthes fimbriata (Grunow) Ross, Cocconeis californica Grunow, Fallacia balnearis (Grunow) A. Witkowski, Lange-Bert., Metzeltin, Licmophora ovulum Mereschk., Rhopalodia gibberula (Ehrenb.) O. Müll., Rhoicosphenia marina (Kütz.) M. Schmidt, Mastogloia ovata Grunow, Navicula pontica (Mereschk.) A. Witkowski, M. Kulikovskiy, E. Nevrova et Lange-Bert., N. menisculus Schumann, and N. witkowskii Lange-Bert., Iserentant et Metzeltin. Totally, 37 plankton, 85 periphyton, and 219 benthos species were found in terms of their habitats. Marine (257 species), brackish (47), and fresh-water (27) organisms were registered in terms of water salinity. In relation to the type of substrates, the following distribution was observed: on macrophytes (219 species), silts (211), sands (205), corals (16), stones (11), and metal rails (5). It has been found that microphytobenthos of the Red Sea and the Black Sea differed in its species composition (the Sorensen-Chekanovsky coefficient of community similarity accounted for 0.42 and the Jaccard coefficient - 0.27).