Mineral content of seaweeds in the inshore waters of Mauritius

The mineral content-Sodium(Na), Potassium(K), calcium(Ca), Magnesium(Mg) and Phosphorus(P) of seawater, sediment and some species of seaweeds namely Sargassum duplicatum, Turbinaria ornata, Padina boryana, Colpomenia sinuosa, Ulva reticulata and Ulva fasciata were investigated. These were the major variety of seaweeds available in the coastal lagoons of Mauritius.The selected sites were Poste Lafayette, Pointe d’Esny, La Cuvette and Pointe aux Sables. Different analytical methods were used in this study.Na, K and Ca were analysed by Flame photometry, Mg was analysed by Atomic Absorption Spectrophotometry and P was analysed by Spectrophotometry.In addition, chlorophyll a content of Ulva species was investigated by Spectrophotometry. It was found that the macromineral profiles were dominated by Ca, Mg K, and Na. The trend in mineral profile of seaweeds followed the sequence Ca> Mg> K>Na. Poste Lafayette was considered as a control site and it was found to have the highest overall mineral concentration(54.109 g/Kg) in seaweeds. Amongst the mineral studied, it was found that calcium was dominant in nearly all the seaweeds studied. This was because most of them were calcareous species.