New Checklist of Marine macroalgae in the coast of El Jadida (Morocco): Temporal variation of physico-chemical parameters of water

Monitoring the diversity of macroalgal communities plays a vital role in assessing the condition of the marine environment. This study, conducted on the Atlantic coast of Saada-El Jadida, aimed to determine the diversity of macroalgae species. It provides a seasonal distribution in the intertidal zone and evaluates the influence of physicochemical parameters on the distribution of macroalgae. The research method utilized the quadratic transect method, and sampling was conducted during four seasons over one year. Identification keys were employed to identify the collected macroalgal species, and physicochemical parameters, including salinity, temperature, pH, nitrate (NO3), nitrite (NO2), orthophosphate (PO4), and dissolved oxygen, were also determined. Ecological index analysis was conducted, while principal component analysis was employed to investigate the relationship between diversity of macroalgae and environmental parameters. The results highlighted significant diversity, with 103 identified species, comprising 70 Rhodophyta, 18 Phaeophyta, and 15 Chlorophyta. The seasonal variations show a notable increase in species richness during the spring season. The diversity of macroalgae at the Saada site is influenced by physical factors such as temperature and salinity, as well as chemical factors including nitrate, nitrite, orthophosphate, and dissolved oxygen. This study provides valuable insights into the dynamic nature of macroalgal communities and their responses to environmental changes, thereby contributing to our understanding of the health and resilience of marine ecosystems on the Atlantic coast of Saada-El Jadida.