Noreddine Rezzoum
The study of algal communities on the El Jadida reef identified a total of 127 taxa divided into 3 systematic groups: 20 Chlorophyceae (16%), 24 Fucophyceae (19%), and 83 Rhodophyceae (65%). Analysis of the marine flora in the study area revealed that 84.25% of the species are Atlantic-Mediterranean, 12.6% are exclusively Atlantic, and only 3.15% are Mediterranean; furthermore, 61.42% are photophilic, while 38.58% are sciaphilous. 82.68% of taxa are associated with the infralittoral zone, and 17.32% are associated with the mediolittoral zone. A study of the brown alga Fucus spiralis showed that its average size ranges from a minimum of 10 cm in January to a maximum of 22.8 cm in July; its maximum fresh biomass was recorded between July and September (6 kg/m²), while the minimum was observed in mid-January (2 kg/m²). The study of Laminaria ochroleuca showed that biomass peaked in late June 2005 (24.57 kg·m⁻² (fresh weight)). Harvesting of this species could take place throughout the summer. Monitoring of the composition of certain trace elements revealed high concentrations in both species.
