In Grateloupia doryphora and Gymnogongrus griffithsiae the seasonal variation of their chemical compounds was studied, establishing a relation with the physical and chemical properties of seawater. High values of proteins in the studied species were detected during the winter, 28.88% in G. doryphora and 26.68% in G. griffithsiae, corresponding to the maximum period of ammonium concentration in the marine environment. The variation in carbohydrates content showed an inverse relation with the proteins, with a maximum of 54.72% in G. doryphora and of 55.36% in G. griffithsiae, both in summer, positively correlated with salinity and temperature of sea water. Lipids content was low in both species. In G. doryphora the values ranged between 0.81 and 1.30% and, in G. griffithsiae, from 0.71 to 1.50% of dry weight, showing a direct relation with the amount of nitrogen in the seawater. The maximum content of ashes, phosphorus and potassium occurred in autumn and winter, respectively, with 11.85%, 0.20%, 1.27% in G. doryphora, and 14.46%, 0.14%, 1.41% in G. griffithsiae.
algae; proteins; carbohidrates; lipids; ashes; nitrogen; phosphorus; potassium