DOI: 10.5061/dryad.9s4mw6msv
title: Photosymbiont and N_P data from Curacao and Barbados

description: Nutrient pollution has been a major contributor to coral decline
 throughout the Caribbean. Coral physiological responses to excess
 nutrients vary with nutrient forms (e.g., nitrate or ammonia),
 concentrations, and nitrogen-to-phosphate (N:P) ratios. However, how these
 responses differ across nutrient contexts remains understudied. We show
 that Orbicella annularis photosymbiont densities respond differently to
 excess nitrogen in phosphorus-limited versus nitrogen-limited
 environments. Along Curaçao's leeward reef, excess nitrogen
 significantly decreased (P &lt; 0.05) photosymbiont density under
 phosphorus-limited conditions (N:P &gt; 16) with low phosphorus (mean
 = 0.07 µM ± 0.06). In contrast, data from Barbados indicate a significant
 increase (P &lt; 0.01) in photosymbiont density under nitrogen-limited
 conditions (N:P &lt; 16). These findings highlight how nutrient
 contexts shape coral responses to nitrogen inputs, emphasizing the need to
 consider nutrient dynamics in coral conservation strategies.
description: # Photosymbiont and N\_P data from Curacao and Barbados
 [https://doi.org/10.5061/dryad.9s4mw6msv](https://doi.org/10.5061/dryad.9s4mw6msv) ## Description of the data and file structure #### File: Photosymbiont\_Curacao\_Barbados\_DataJune2025.xlsx This dataset compiles environmental and biological data relevant to photosymbiotic corals from Curacao and Barbados. The dataset includes time series of nutrient concentrations, calculated nutrient ratios (e.g., N:P), and symbiont densities for coral samples from both locations, along with additional metadata. The dataset is intended to support analyses exploring the relationship between nutrient regimes and coral photosymbiosis across temporal and spatial gradients. | Column Name | Description | | :------------------------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `Date_for_comparison_Y` | Year for comparative analysis (numeric, e.g., 1988, 1990). | | `Year_placeholder` | Placeholder or grouping code for year (for alignment or visualization). | | `Date_for_comparison_M` | Month for comparative analysis (numeric, 1–12). | | `wet_dry` | Seasonality code (0 = dry season, 1 = wet season). | | `Season` | Season label corresponding to `wet_dry` (e.g., `dry`, `wet`). | | `NP_timeseries` | N:P ratio time series derived from environmental data. | | `PO34- (µM)` | Phosphate concentration in micromolar (µM). | | `DATE` | Year as a numeric value (redundant with Date\_for\_comparison\_Y). | | `average NP` | Average N:P ratio for that date or period calculated for Curaçao. | | `stdev NP` | Standard deviation of N:P ratio for that date or period calculated for Curaçao. | | `Site` | Sampling location identifier (for Curaçao). | | `Date_for_comparison` | Date for previously used supplementary figure (not in manuscript). | | `N_P ratio` | Measured Nitrogen-to-Phosphorus ratio for previously used supplementary figure (not in manuscript). | | `placeholder` | Additional placeholder column for previously used supplementary figure (not in manuscript). | | `TDN:TDP LOC` | Placeholder for Figure 2b. | | `NP_2013_2015` | N:P ratio derived from 2013–2015 data subset for figure 2b based on sites closest to location identifier for Curaçao (N/A are values where no N:P could be derived due to missing measurements of either N or P or both) | | `colony` | Identifier for coral colony sampled. | | `Averageof15N` | Average δ15N isotopic value (per mil, ‰), indicative of nitrogen source. | | `mean_N_calculated` | Mean nitrogen concentration calculated based on mean N of macroalgae for Curaçao (in micromolar (µM). | | `mean_N_2` | mean N of macroalgae for Curaçao | | `zooxd2` | Photosymbiont density for Curacao (# of cells × 10^6/cm²). | | `calculated zooxd` | Photosymbiont density calculated from raw counts for Curacao. | | `Curacao zoox/cm3` | Photosymbiont density standardized to Curacao coral samples (cells/cm³). | | `N:P 1981_1982 (Glodap.v2_2022)` | Historical N:P ratio from GLODAP.v2 (2022) dataset for 1981 to 1982. | | `TDN:TDP LOC_Barbados` | placeholder for Barbados (N:P ratio). | | `zooxdensityBarbados` | Photosymbiont density in Barbados samples (cells × 10^6/cm³ or other units). | | `Barbados zoox/cm3` | Photosymbiont density standardized to Barbados coral samples (cells/cm³). | | `N add_Barbados` | Additional nitrogen from ladbased sources for Barbados samples (in µM). | | `month_T` | Month of the year (abbreviated as `Jan`, `Feb`, etc.) corresponding to temperature and precipitation data. | | `avg_T` | Long-term average sea surface temperature (°C) for the corresponding month for Curaçao. | | `stdev_T` | Standard deviation of sea surface temperature (°C) for the corresponding month, representing interannual variability for Curaçao. | | `avg_precip` | Long-term average precipitation (mm/day) for the corresponding month for Curaçao. | | `stdev_precip` | Standard deviation of precipitation (mm/day) for the corresponding month, representing interannual variability for Curaçao. |