Spatiotemporal variation in phenology of the invasive brown macroalga Sargassum muticum (Yendo) Fensholt and the environmental parameters relationships along four different sites on the Atlantic coast of Morocco

Abstract

The alien brown seaweed Sargassum muticum (Yendo) Fensholt is currently observed along the coasts of Morocco. The present study aimed to evaluate the impact of physicochemical parameters on the distribution of S. muticum at four sites on the Atlantic coast of Morocco harvested between 2019 and 2020. This study showed that the highest biomass, thalli length, and fertility values were recorded in sampling sites characterized by optimal physicochemical (temperature, pH, and salinity) and nutrient H₃PO₄ during summer. The highest biomass values were recorded in August for Sidi Bouzid and Moulay Abdellah sites, conversely, in Saada and Jorf Lasfar sites the highest values were observed in February and March respectively. The thallus length was slightly larger in Moulay Abdellah site with 77.30 ± 14.09 cm compared with the three other sites during the summer/spring periods. Minimum thalli length was recorded in September for all studied sites. The thalli of S. muticum were fertile earlier in Sidi Bouzid and Saada during spring and peaked during the summer season for all studied sites showing a positive correlation with increasing temperature. Finally, the collected data shows that indeed physicochemical parameters influence bioecological parameters. Thus, contributed to a better understanding of the temporal variation of S. muticum phenology on the Moroccan Atlantic coast, these data provide the necessary information for coastal marine management and biomonitoring program as well as sustainable utilization of this renewable marine resource.