The present investigation revealed that Red sea stretches along Marsa Alam of Egypt is a habitation of diverse groups of marine macro-algal species recorded along Marsa Hemera shore. Ecological studies (meteorological data, water, soil, aqueous extract analysis of Sargassum muticum (Yendo) Fensholt and associated species) reported that, slightly alkaline; low turbidity, moderate temperature and available nutrient content of saline water produced massive growth of S. muticum during September (2018). Ecological and Physico-chemical properties of collected water samples showed variations of different parameters of sea water like temperature, salinity, pH, and high dissolved minerals. Heavy metals accumulation inside the investigated seaweeds S. muticum was within the corresponding range. The aqueous extract of S. muticum contained high amounts of Na, Ca, K and Fe, moderate amounts of Zn, and low in Cu, Cd, Ni and Mn. Lead Pb recorded 0.291 ppm, Ag, Co and Ga were absent in aqueous extract. The associated species to the brown algae S. muticum are belonging to 6 families and 7 species as follows: Sargassaceae, Fucaceae, Phaeophyceae, Rhodomelaceae, Caulerpaceae and Hydrocharitaceae. Results showed that S. muticum enriched in essential amino acids; micro and macro elements, carbohydrates, protein, lipids, and agar. These algae may be used as bio fertilizers.