Standing Stock, Agar Yield and Properties of <i>Gracilaria salicornia</i> Harvested along the Tanzanian Coast

Abstract

Keywords: Gracilaria salicornia , agar, yield, productivity, biomass, Tanzania Seasonal biomass variation and agar yield of G. salicornia (C. Ag.) Dawson from Oyster Bay, Dar es Salaam, and Chwaka Bay, Zanzibar, were determined, and some properties of the agar examined. Mean biomass and canopy cover values ranged from 21–60 g/m2 and 7– 20 %, respectively. The highest mean biomass and cover values were obtained during the SE monsoon. Agar yield varied from 13.7 to 30.2 % (dry weight) and was highest during the dry NE monsoon period. Alkali treatment generally reduced agar yield by 25–56 %. Gel strength of the agar gels ranged between 118 and 251 g/cm2 and was significantly higher during the NE monsoon period (t = 2.2; P = 0.04 and t = 8.9; P