Hot springs have received attention in thermal systems
around the world. Particularly, as they relate to Diatoms. Diatoms
biodiversity of thermal springs in the southwest region, Saudi
Arabia was studied. Seasonal collections were carried out in Gizan
thermal springs in six localities from winter 2015 to autumn 2016.
A total of 23 species have been identified, recorded based on their
frequency. Fifteen species were considered the most dominant
species. The majority of it is the inhabitant of Qowah spring,
Diatoms present in high abundance in 80% of thermal spring in
Gizan region. This may indicate that diatoms have an essential
biological role in the development and stability of the thermal
spring ecosystem. Diatoms are the most frequent species present in
Saudi Arabia thermal springs based on this study. Four species
Cocconeis pinnata, Cocconeis scutellum, Hantzschia amphioxys ,
and Melosira varians were only recorded in Qowah and are the
only rare diatoms species. In this study, rare species with respect
to all sites were abundant in Qowah. Therefore, Qowah is a
reservoir of those rare species. Accordingly, Qowah protection
will help protect these rare species. Indeed, it is recommended to
generate regulations to protect biodiversity in Qowah thermal
spring