Seasonal variations in Na, K, Mg and Ca and charge balance in marine brown algae from Saurashtra coast (NW coast of India)

Abstract

Seasonal variation of Na, K, Mg and Ca were estimated in Cystoseira indica, Sargassum tenerrimum and S. johnstonii. Abundance of these elements were higher during the rapid growth stage but decreased subsequently. Monovalent cations (Na + K) strongly correlated with Cl content suggesting that these cations were balanced by chloride ions. Divalent cations (Ca + Mg) seem to be balanced by the anion sulphate. Ash content of the algae was accounted by these major cations and anions. Charge equivalent among these cations and anions was not balanced in the ash of the algae. The cations charge equivalence could be balanced by chloride and sulphate in addition to the anions of C, N and P origin (OH-, RCOO(-) H2PO3- etc.). A significant correlation (P <0.001) between per cent of negative ions deficit and per cent of excessive unbalanced cations was observed. Perhaps 9-32% (on large data base upto 60%) of the organic matter participate in charge balance of cations. Intertidal position seemed to affect the osmoregulation process.