Spatial variations in the stable isotope composition of the green algae, Halimeda tuna, on Conch Reef, Florida Keys, USA and implications for paleothermometry

On Conch Reef, Florida Keys, USA we examine the interaction of local hydrography and the complex reef topography on the pattern of stable isotope (δ18O and δ13C) signatures in the benthic green algae, Halimeda tuna.  During the summer months, benthic temperatures show high-frequency fluctuations associated with the arrival of internal waves that advect cool, nutrient rich water across the reef slope. The nutrient and temperature regime available for H. tuna growth across the reef is modified by the interaction between local water flow and reef morphology and results in a highly heterogenous growth environment even within isobaths. This environmental heterogeneity in then reflected in the large variability in isotopic signatures even among closely located individuals. Comparing the temperature measured across the reef front with that predicted by the δ18O isotopic thermometer suggests complex interactions between the environment and Halimeda carbonate formation at temporal and spatial scales not normally considered in mixed or averaged sediment samples. The divergence in estimated temperature range between measured and predicted temperatures emphasizes species and location specific temperature relationships. The relatively light δ18O signatures, compared to other model measurements, may also indicate freshwater input at Conch Reef. These observations illustrate the need to consider this spatial heterogeneity in contemporary as well as ancient reef settings that are influenced by a similar, highly variable physical environment.

Disciplines

Biological oceanography, Marine geology

Keywords

Halimeda, paleothermometry, stable isotope

Location

23.854474N, 4.368293S, -58.527783E, -90.102581W

Data

FileSizeFormatProcessingAccess
CRZ show coordinates
22 KoTEXTProcessed data
CR Y data coordinate file
748 octetsTEXTProcessed data
CR X coordinates
529 octetsTEXTProcessed data
CR sigma temperatures on grid
22 KoTEXTProcessed data
CR isotope data part 1
9 KoTEXTProcessed data
CR isotope data part 2
3 KoTEXTProcessed data
Benthic water temperature at 10, 20, 30 m on Conch Reef, Florida from 1996 to 2007
19 MoCSVQuality controlled data
How to cite
Stokes Dale (2020). Spatial variations in the stable isotope composition of the green algae, Halimeda tuna, on Conch Reef, Florida Keys, USA and implications for paleothermometry. SEANOE. https://doi.org/10.17882/61374
In addition to properly cite this dataset, it would be appreciated that the following work(s) be cited too, when using this dataset in a publication :
Stokes M. Dale, Leichter James J., Wing Stephen R. (2020). Spatial variations in the stable isotope composition of the benthic algae, Halimeda tuna, and implications for paleothermometry. Scientific Reports, 10 (1), -. https://doi.org/10.1038/s41598-020-73283-x

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