Mineralogic Changes during Growth in the Red Alga, Clathromorphum compactum

Abstract

The amount of magnesium in the skeletal calcite of the encrusting marine red alga Clathromorphum compactum varies seasonally in response to changes in water temperature. X-ray diffraction analyses of serial samples of this alga collected in the Gulf of Maine indicate more than a 40-percent change in composition during a year and demonstrate a more rapid calcification during warmer periods.