Kinetic and Metabolic Isotope Effects in Zooxanthellate and Non-zooxanthellate Mediterranean Corals Along a Wide Latitudinal Gradient

Fiorella Prada, Ruth Yam, Oren Levy, Erik Caroselli, Giuseppe Falini, Zvy Dubinsky, Stefano Goffredo, Aldo Shemesh

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


Many calcifying organisms exert significant biological control over the construction and composition of biominerals which are thus generally depleted in oxygen-18 and carbon-13 relative to the isotopic ratios of abiogenic aragonite. The skeletal δ18O and δ13C values of specimens of Mediterranean zooxanthellate (Balanophyllia europaea and Cladocora caespitosa) and non-zooxanthellate corals (Leptopsammia pruvoti and Caryophyllia inornata) were assessed along an 8° latitudinal gradient along Western Italian coasts, spanning ∼2°C and ∼37 W m–2 of annual average sea surface temperature and solar radiation (surface values), respectively. Seawater δ18O and δ13CDIC were surprisingly constant along the ∼850 km latitudinal gradient while a ∼2 and ∼4% variation in skeletal δ18O and a ∼4 and ∼9% variation in skeletal δ13C was found in the zooxanthellate and non-zooxanthellate species, respectively. Albeit Mediterranean corals considered in this study are slow growing, only a limited number of non-zooxanthellate specimens exhibited skeletal δ18O equilibrium values while all δ13C values in the four species were depleted in comparison to the estimated isotopic equilibrium with ambient seawater, suggesting that these temperate corals cannot be used for thermometry-based seawater reconstruction. Calcification rate, linear extension rate, and skeletal density were unrelated to isotopic compositions. The fact that skeletal δ18O and δ13C of zooxanthellate corals were confined to a narrower range at the most isotopically depleted end compared to non-zooxanthellate corals, suggests that the photosynthetic activity may restrict corals to a limited range of isotopic composition, away from isotopic equilibrium for both isotopes. Our data show that individual corals within the same species express the full range of isotope fractionation. These results suggest that metabolic and/or kinetic effects may act as controlling factors of isotope variability of skeleton composition along the transect, and that precipitation of coral skeletal aragonite occurs under controlling kinetic biological processes, rather than thermodynamic control, by yet unidentified mechanisms.

Original languageEnglish
Article number522
JournalFrontiers in Marine Science
StatePublished - 10 Sep 2019

Bibliographical note

Funding Information:
The authors would like to thank the diving centers Centro Immersioni Pantelleria, Il Pesciolino, Bubble Lounge, and Sub Maldive for their logistic assistance in the field. The Scientific Diving School ( provided the technical and logistical support. The De Botton Center for Marine Science at the Weizmann Institute provided partial support. Funding. The research leading to these results was supported by the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement number (249930- CoralWarm: Corals and global warming: the Mediterranean versus the Red Sea). EC was supported by the ALMA IDEA grant of the University of Bologna for the project “STRAMICRO.”

Publisher Copyright:
© Copyright © 2019 Prada, Yam, Levy, Caroselli, Falini, Dubinsky, Goffredo and Shemesh.


  • Mediterranean Sea
  • isotopic discrimination
  • kinetic isotope effects
  • stable isotopes
  • temperate corals
  • vital effects


Dive into the research topics of 'Kinetic and Metabolic Isotope Effects in Zooxanthellate and Non-zooxanthellate Mediterranean Corals Along a Wide Latitudinal Gradient'. Together they form a unique fingerprint.

Cite this