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.Marine organisms deposit skeletal parts composed of a wide variety of mineral forms. Among the carbonatesecreting groups, the minerals calcite, aragonite, and a variety of magnesium calcites (1) are common (2, 3). Green algae deposit aragonite exclusively. Red algae deposit both aragonite and magnesium calcites, the latter containing up to 30 mole percent magnesium, calculated as MgCO3, in solid solution in the calcite (1).The coccolithophores deposit a calcite very low in magnesium.Clarke and Wheeler (4) and Chave (2) have shown that in calcite-secreting groups of marine organisms, the magnesium content of the whole calcitic tests increases almost linearly with water temperature over the range 0? to 30?C. Thus tropical forms of a given taxon have a higher magnesium content than their boreal counterparts. During an attempt to determine the rate of growth and calcification in an individual encrustation of the red alga Clathromorphum compactum, we found that seasonal changes in the magnesium content of the skeletal calcite could be detected.Because of the small radius of the symposium on Assessment of Radioactive Body Burdens in Man, Heidelberg, Germany, 11-16 May 1964 (International Atomic Energy Agency, in press). 4. J. Miettinen, ibid. 5. R. W. Perkins and J. M. Nielsen, Hanford Doc. No. HW-SA-3487. 6. We thank the PHS for the use of hospital facilities at Kotzebue, and M. C. Brewer, director of the Arctic Research Laboratory, for assisting in providing transportation and facilities in northern Alaska.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.

Unusual Crystal Formation in Organisms - Exceptions that Confirm Biomineralization Rules

“…The fact that magnesium calcite is the dominant component is in agreement with statements of numerous literature data (Linck, 1930;Babička, 1936;Vinogradov, 1953;Chave, 1954;Chave & Wheeler, 1965;Walker & Moss, 1984;James at al., 1988;Borowitzka, 1989;Aharon, 1991;Pueschel et al, 1992). Most of the authors found that the magnesium content in Corallinacea ranged from 2 to 30 molar % (M %).…”

“…The same authors observed that calcification of crustose corralines was slower than that in articulated species. Taking into consideration all these facts we may accept the hypothesis that the mineral composition of corralinacean algae varies with algal age (Vinogradov, 1953) and growth rate (Chave & Wheeler, 1965), but we cannot explain why algal species show similar crystallite sizes. Unusual and unexplained results described in this study relate on high amount (75 to 80 M%) of mineral aragonite in the algae Pseudolithophyllum expansum collected at Kornati Islands in two independent sampling during 1987 and 1988.…”

The Coralline Genus Clathromorphum Foslie emend. Adey: Biological, Physiological, and Ecological Factors Controlling Carbonate Production in an Arctic-Subarctic Climate Archive

“…In the colder Subarctic, the principal habitat of C. compactum, they are considerably thinner and drop below 100 µm yr -1 in the Arctic. Although the potential for climate archiving with corallines has been known since the 1960s (Adey, 1965;Chave and Wheeler, 1965), its application has been frustrated until recently by a lack of understanding of their anatomical complexity and its irregularities, as well as by the lack of appropriate instrumental tools.…”

“…The magnesium content of coralline algal skeletons records temperature changes (Figures 3, 4; Adey, 1965;Chave and Wheeler, 1965 ; 1950-2004); r annual = 0.51, p < 0.001 (Gamboa et al, 2010).…”

High-Resolution Mg/Ca Ratios in a Coralline Red Alga as a Proxy for Bering Sea Temperature Variations From 1902 to 1967

“…Seasonally changing Mg content within annually banded coralline algae positively correlates to the sea surface temperatures (SSTs) of the water in which they formed (Chave, 1954;Adey, 1965 ;Chave and Wheeler Jr., 1965;Hetzinger et al, 2009;Kamenos et al, 2008), although light-and temperature-driven growth rates may also influence Mg content (Kolesar, 1978;Moberly, 1968). Using the Lithothamnion glaciale MgCO 3 -SST relationship established by Halfar et al (2000) the mol% values measured here were converted to temperature:…”