Compositional variability in a cold-water scleractinian, Lophelia pertusa: New insights into "vital effects"


Journal Article

We analyzed Sr/Ca and Mg/Ca ratios in the thecal wall of Lophelia pertusa, a cold-water coral, using SIMS ion microprobe techniques. The wall grows by simultaneous upward extension and outward thickening. Compositional variability displays similar trends along the upward and outward growth axes. Sr/Ca and Mg/Ca ratios oscillate systematically and inversely. The sensitivity of Lophelia Sr/Ca ratios to the annual temperature cycle (-0.18 mmol · mol -1/°C) is twice as strong as that exhibited by tropical reef corals, and four times as strong as the temperature dependence of Sr/Ca ratios of abiogenic aragonites precipitated experimentally from seawater. A comparison of the skeletal composition of Lophelia with results from precipitation calculations carried out using experimentally determined partition coefficients suggests that both temperature-dependent element partitioning and seasonal changes in the mass fraction of aragonite precipitated from the calcifying fluid influence the composition of Lophelia skeleton. Results from calculations that combine these effects reproduce both the exaggerated amplitude of the Sr/Ca and Mg/Ca oscillations and the inverse relationship between Sr/Ca and Mg/Ca ratios. Copyright 2006 by the American Geophysical Union.

Full Text

Duke Authors

Cited Authors

  • Cohen, AL; Gaetani, GA; Lundälv, T; Corliss, BH; George, RY

Published Date

  • December 1, 2006

Published In

Volume / Issue

  • 7 / 12

Electronic International Standard Serial Number (EISSN)

  • 1525-2027

International Standard Serial Number (ISSN)

  • 1525-2027

Digital Object Identifier (DOI)

  • 10.1029/2006GC001354

Citation Source

  • Scopus