DOI: 10.5061/dryad.37pvmcvxr
title: Marine heatwave-driven mortality of bleached colonies of the massive coral <em>Goniopora</em> is exacerbated by a black band disease epizootic

description: During the recent fourth global mass coral bleaching event, the Great
 Barrier Reef (GBR) experienced the highest temperatures for centuries and
 widespread bleaching. For massive, long-lived Goniopora, bleaching
 coincided with a black band disease (BBD) epizootic at One Tree
 Reef (OTR). This necrotic wasting disease, typically rare on the
 GBR, appeared along the edge of bleached polyps. We tracked
 112 Goniopora colonies from bleaching onset through winter to
 summer in seven surveys. In February 2024, 75% of colonies were bleached,
 and 4% of these had BBD. By April, 61% of bleached colonies had
 an aggressive black band invading the tissue. For heat-stressed
 and diseased Goniopora, winter cooling did not promote substantial
 recovery, with 75% of tagged colonies dead by October. Only 24%
 of tagged colonies recovered, albeit with partial mortality.
 Population surveys at two sites showed a similar bleaching-disease pattern
 with high mortality by October (46% and 66%). Repeated health
 assessments revealed a link between bleaching, disease, and heat
 in the demise of these normally resilient massive colonies, many
 of which have been lost at OTR. Understanding the connection
 between the ‘evil twins’ of bleaching and disease is important as
 corals are faced with unprecedented thermal anomalies.
description: # Marine heatwave-driven mortality of bleached colonies of the massive
 coral *Goniopora* is exacerbated by a black band disease epizootic Dataset
 DOI: [10.5061/dryad.37pvmcvxr](https://doi.org/10.5061/dryad.37pvmcvxr) ##
 Description of the data and file structure This dataset was collected at
 One Tree Reef, located in the southern Great Barrier Reef, between
 February 2024 and February 2025, to track bleaching and disease in
 *Goniopora* corals. It includes three components: 1. **Tagged colony
 dataset** - 112 individual *Goniopora* colonies were photographed and
 assessed at seven time points for bleaching, black band disease (BBD),
 recovery, mortality, and polyp colour. Image analysis was used to quantify
 disease progression in a subset of colonies. (File
 name: Byrne_et_al_2025_Black_Band_Disease\_ One_Tree_Island\_
 Goniopora_tracking_data.csv) 2. **Population surveys** - Surveys conducted
 in May and October 2024 documented the health status of 720 colonies
 across two lagoon sites (Gutter and Shark Alley). Data were used to
 analyse *Goniopora* colonies observed at One Tree Island that were dead or
 in varying states with black band disease associated with the 2024
 bleaching event. Colony condition was categorised as normal, bleached,
 diseased, or dead. (File
 name: Byrne_et_al_2025_Black_Band_Disease_One_Tree_Island_Goniopora_category_data.csv) 3. **In situ temperature data** - In situ temperature data (One Tree Island): Contains seawater temperature records collected from loggers deployed at coral depth. Raw data were retrieved directly from field instruments and processed to daily mean temperatures to remove sub-daily variability and noise. (File name: Byrne_et_al_2025_Black_Band_Disease_One_Tree_Island_Temp_Data_in_situ_loggers.csv) 4. **Satellite temperature data** - CRW Satellite Sea Surface Temperature (SST) data (One Tree Island): Contains daily SST records derived from the NOAA Coral Reef Watch (CRW) satellite product for the One Tree Island region. Satellite data were extracted, quality-controlled, and processed to daily mean temperatures to ensure consistency with in situ logger data. (File name: Byrne_et_al_2025_Black_Band_Disease_One_Tree_Island_Temp_Data_CRW_Satellite_SST.csv) ### Files and variables #### File: Byrne_et_al_2025_BBD.Rmd **Description:** This R Markdown script (**Byrne_et_al_2025_BBD.Rmd**) was used to import, clean, and analyse data from One Tree Island to investigate bleaching and black band disease (BBD) in *Goniopora* corals during the 2024 bleaching event. Analyses included frequency plots and GLMs of colony health states from population surveys, as well as processing of in situ and satellite temperature datasets. Temperature analyses involved temporal alignment, cleaning of non-finite values, climatology computation, and marine heatwave detection using the *heatwaveR* package. #### File: Byrne_et_al_2025_Black_Band_Disease__One_Tree_Island__Goniopora_tracking_data.csv **Description:** This dataset contains observations of 112 tracked *Goniopora* colonies photographed and monitored at One Tree Island, southern Great Barrier Reef, across seven time points between February 2024 and February 2025. Each colony was assessed for bleaching, black band disease (BBD), recovery, mortality, and polyp colour. The data were used to analyse colony health states and the occurrence of BBD associated with the 2024 bleaching event. ##### Variables * Colony Number: 1-112 * Location: Gutter, Shark Alley * Day: 0, 40, 74, 134, 231, 266, 361 * Presence of BBD: 0 (absence), 1 (presence)  * Category: Normal colour, Bleached, Dead, Recovered  * Polyp Colour: White, Yellow, Brown, Purple #### File: Byrne_et_al_2025_Black_Band_Disease__One_Tree_Island_Temp_Data_CRW_Satellite_SST.csv **Description:** This dataset contains daily sea surface temperature (SST) records derived from the NOAA Coral Reef Watch (CRW) satellite product for the One Tree Island region. The raw satellite data were extracted, quality-controlled, and processed to daily mean temperatures to ensure consistency with in situ logger data. The dataset was imported and analysed in R using the script *Byrne et al_2025_BBD.Rmd*. Analytical steps included temporal alignment, cleaning of non-finite values, climatology computation, and marine heatwave detection and categorisation using the heatwaveR package. ##### Variables * t: date * temp: mean. daily temperature (°C) #### File: Byrne_et_al_2025_Black_Band_Disease__One_Tree_Island_Temp_Data_in_situ_loggers.csv **Description:** This dataset contains in situ seawater temperature records collected from temperature loggers deployed at One Tree Island, located in the southern Great Barrier Reef. Raw data were retrieved directly from field instruments and subsequently processed to daily mean temperatures to remove sub-daily variability and noise. Data were imported and analysed in R using the script *Byrne et al_2025_BBD.Rmd*. Processing included date–time standardisation, cleaning of non-finite values, and calculation of daily means prior to climatology and marine heatwave detection analyses performed with the heatwaveR package. ##### Variables * t: date * temp: mean. daily temperature (°C) #### File: Byrne_et_al_2025_Black_Band_Disease_One_Tree_Island_Goniopora_category_data.csv **Description:** Data used to analyse *Goniopora* colonies observed at One Tree Island to be dead or a various states with black band disease associated with the 2024 bleaching event. These data were used in frequency plots and GLM analyses in the Rscript "Byrne et al_2025_BBD.Rmd. Photos were obtained at two sites and two dates in the first lagoon of One Tree Island: Gutter and Shark Alley and in May and October of 2024. The analysed data represent a subset of the total data collection effort. The final subset of images used here for analysis was obtained randomly, and details can be found in the methods of the respective paper. ##### Variables * "Unique_ID": a unique ref number containing a "sequential value" + "_" + "the photo ID from which the colony category was determined". * "Location": Gutter, Shark Alley * "Date": May, October  * "Presence of BBD": 0 (absence), 1 (presence) * "Category": Normal colour with black band disease, Normal colour with no black band disease, Bleached with black band disease, Bleached with no black band disease, Dead. * "Frequency": Binary indicator denoting whether the observed coral colony belongs to the specified health category ("Category") at a given site and date. 0 (colony not observed in that category), 1 (colony was observed in that category). ## Code/software Data were processed and analysed in R (version 4.3.2) using open-source packages including *tidyverse* (for data cleaning and plotting) and *heatwaveR* (for climatology and marine heatwave detection). The workflow is documented in the accompanying script **Byrne_et_al_2025_BBD.Rmd**, which imports and analyses coral health and temperature datasets from One Tree Island. ## Access information Data was derived from the following sources: * All data are original and were collected by the authors at One Tree Island, southern Great Barrier Reef, between February 2024 and February 2025. Satellite sea surface temperature data were derived from the publicly available NOAA Coral Reef Watch (CRW) product ([https://coralreefwatch.noaa.gov/](https://coralreefwatch.noaa.gov/)), provided under the NOAA Open Data License. All data were generated by the authors during this study and are released under a CC0 public-domain waiver. No third-party copyrighted material is included.