Data_Sheet_1_Lateral, Vertical, and Temporal Variability of Seawater Carbonate Chemistry at Hog Reef, Bermuda.docx

• Main Authors: Ariel K. Pezner, Travis A. Courtney, Heather N. Page, Sarah N. Giddings, Cory M. Beatty, Michael D. DeGrandpre, Andreas J. Andersson
• Format: Dataset
• Language: unknown
• Published: 2021
• Subjects: Oceanography; Marine Biology; Marine Geoscience; Biological Oceanography; Chemical Oceanography; Physical Oceanography; Marine Engineering; carbonate chemistry; ocean acidification; calcification; coral reef; Hog Reef; Bermuda; reef metabolism; Ocean acidification
• Online Access: https://doi.org/10.3389/fmars.2021.562267.s001; https://figshare.com/articles/dataset/Data_Sheet_1_Lateral_Vertical_and_Temporal_Variability_of_Seawater_Carbonate_Chemistry_at_Hog_Reef_Bermuda_docx/13891226

Spatial and temporal carbonate chemistry variability on coral reefs is influenced by a combination of seawater hydrodynamics, geomorphology, and biogeochemical processes, though their relative influence varies by site. It is often assumed that the water column above most reefs is well-mixed with small to no gradients outside of the benthic boundary layer. However, few studies to date have explored the processes and properties controlling these multi-dimensional gradients. Here, we investigated the lateral, vertical, and temporal variability of seawater carbonate chemistry on a Bermudan rim reef using a combination of spatial seawater chemistry surveys and autonomous in situ sensors. Instruments were deployed at Hog Reef measuring current flow, seawater temperature, salinity, pH T , pCO 2 , dissolved oxygen (DO), and total alkalinity (TA) on the benthos, and temperature, salinity, DO, and pCO 2 at the surface. Water samples from spatial surveys were collected from surface and bottom depths at 13 stations covering ∼3 km 2 across 4 days. High frequency temporal variability in carbonate chemistry was driven by a combination of diel light and mixed semi-diurnal tidal cycles on the reef. Daytime gradients in DO between the surface and the benthos suggested significant water column production contributing to distinct diel trends in pH T , pCO 2 , and DO, but not TA. We hypothesize these differences reflect the differential effect of biogeochemical processes important in both the water column and benthos (organic carbon production/respiration) vs. processes mainly occurring on the benthos (calcium carbonate production/dissolution). Locally at Hog Reef, the relative magnitude of the diel variability of organic carbon production/respiration was 1.4–4.6 times larger than that of calcium carbonate production/dissolution, though estimates of net organic carbon production and calcification based on inshore-offshore chemical gradients revealed net heterotrophy (−118 ± 51 mmol m –2 day –1 ) and net calcification (150 ± 37 mmol ...