Spatial and temporal variations in the nutritional composition of some seaweeds from the Red Sea, Egypt

Abstract

Spatial and seasonal variations in the nutritional composition of the dominant seaweed species were assessed at three sites during 2017 from Hurghada and Safaga of the Red Sea coast. Results showed that six species were dominant and had the highest coverage during the year of study. The proximate composition of these seaweeds showed as a significant difference among sites and seasons and the correlation with the environmental parameters were established. Total carbohydrates were higher and more varied among seasons (12.1- 41.9% dry wt.). Carbohydrate levels were positively correlated with seawater temperature, pH value, and salinity. Total soluble protein of these seaweeds was varied significantly between seasons (3.2-8.3 % dry wt.) with the highest values in winter while there is no a significant difference between the sites. The protein levels were positively correlated with dissolved nitrate and silicate but negatively correlated with water temperature. Total lipid content of the tested seaweeds was varied between 1.1 % dry wt. during winter and 0.6 % dry wt. during spring and it was significantly correlated with nitrite and pH value. Fibers content of the tested seaweeds were varied among the sites and seasons (26.5-53.5 % dry wt.). While, Ash content was not varied among the sites and seasons.