Carrageenan ecology of Gigartina stellata (Stackhouse) Batters

Seasonal variations of carrageenan and other biochemical properties in estuarine and open coastal populations of Gigartina stellata (Stackhouse) Batters were recorded monthly during 1972–1973. Protein and viscosity values were highest during late winter—early spring when nitrogen nutrient levels were highest. The levels of carbohydrate and carrageenan exhibited erratic and minimal seasonal variations, even so the lowest values were found during the spring periods of maximum protein levels. Estuarine populations of Gigartina exhibited lower protein and greater carrageenan contents than open coastal populations; earlier studies with the closely related red alga, Chondrus crispus Stackhouse, showed the opposite situation. Differential physiologies and tolerances of Chondrus and Gigartina may explain their contrasting biochemical properties