DOI: 10.5061/dryad.v15dv4281
title: Data from: Controlled out-of-season spawning of reef-forming corals using offset environmental cues

description: The global climate crisis has heightened the urgency for developing
 interventions to enhance resilience and recovery of coral reef ecosystems.
 However, research programs are often bottlenecked by availability of coral
 early life stage material due to the annual nature of coral mass spawning.
 We present a proof-of-concept of “out-of-season” spawning, utilising
 aquarium control technology to induce spawning in multiple Great Barrier
 Reef (GBR) corals held in long-term indoor aquaria. By applying a 6-month
 offset environmental profile encompassing seasonal temperature,
 photoperiod, and lunar cues, we induced synchronised coral spawning during
 austral autumn/winter between 2022-2023. We also “phase-shifted” the hour
 of sunset by four hours on spawning nights, creating a more favourable
 time window (i.e., minimising late nights) for gamete fertilisation.
 Spawning occurred on comparable nights after full moon (NAFM) and at
 similar times after sunset (TAS) to wild conspecifics, with 2023 cohorts
 showing the closest alignment. Gamete fertilisation was successful for six
 species: Acropora millepora, Acropora loripes, Acropora hyacinthus,
 Acropora elseyi, Acropora austera, and Montipora aequituberculata
 producing ~1.8 million larvae. We outline physiological insights into
 environmental regulation of coral spawning synchronicity and discuss the
 potential for out-of-season spawning to accelerate coral research and
 enhance reef restoration programs.
description: # Controlled out-of-season spawning of reef-forming corals using offset
 environmental cues # Short summary of study: We present a proof-of-concept
 of “out-of-season” spawning, utilising aquarium control technology to
 induce spawning in multiple Great Barrier Reef (GBR) corals held in
 long-term indoor aquaria. By applying a 6-month offset environmental
 profile encompassing seasonal temperature, photoperiod, and lunar cues, we
 induced synchronised coral spawning during austral autumn/winter between
 2022-2023. We also “phase-shifted” the hour of sunset by four hours on
 spawning nights, creating a more favourable time window (i.e., minimising
 late nights) for gamete fertilisation. Spawning occurred on comparable
 nights after full moon (NAFM) and at similar times after sunset (TAS) to
 wild conspecifics, with 2023 cohorts showing the closest alignment. Gamete
 fertilisation was successful for six species: *Acropora millepora,
 Acropora loripes, Acropora hyacinthus, Acropora elseyi, Acropora austera,
 and Montipora aequituberculata* producing ~1.8 million larvae. We outline
 physiological insights into environmental regulation of coral spawning
 synchronicity and discuss the potential for out-of-season spawning to
 accelerate coral research and enhance reef restoration programs. # Code
 and Package Versions: ## Code/software ### R version 4.4.0 ### libraries
 required * library(tidyverse) * library(readxl) * library(scales) *
 library(car) * library(lubridate) * library(emmeans) ### sessionInfo() \##
 R version 4.4.0 (2024-04-24 ucrt)\ \## Platform: x86_64-w64-mingw32/x64\
 \## Running under: Windows 10 x64 (build 19045)\ \## \ \## Matrix
 products: default\ \## \ \## \ \## locale:\ \## [1]
 LC_COLLATE=English_Australia.utf8  LC_CTYPE=English_Australia.utf8   \ \##
 [3] LC_MONETARY=English_Australia.utf8 LC_NUMERIC=C                      \
 \## [5] LC_TIME=English_Australia.utf8    \ \## \ \## time zone:
 Australia/Brisbane\ \## tzcode source: internal\ \## \ \## attached base
 packages:\ \## [1] stats     graphics  grDevices utils     datasets 
 methods   base     \ \## \ \## other attached packages:\ \##  [1]
 emmeans_1.8.8   car_3.1-2       carData_3.0-5   scales_1.4.0   \ \##  [5]
 readxl_1.4.5    lubridate_1.9.4 forcats_1.0.0   stringr_1.5.1  \ \##  [9]
 dplyr_1.1.4     purrr_1.0.4     readr_2.1.5     tidyr_1.3.1    \ \## [13]
 tibble_3.3.0    ggplot2_3.5.2   tidyverse_2.0.0\ \## \ \## loaded via a
 namespace (and not attached):\ \##  [1] gtable_0.3.6      
 compiler_4.4.0     tidyselect_1.2.1   yaml_2.3.10       \ \##  [5]
 fastmap_1.2.0      R6_2.6.1           generics_0.1.4     knitr_1.50       
 \ \##  [9] pillar_1.10.2      RColorBrewer_1.1-3 tzdb_0.5.0        
 rlang_1.1.6       \ \## [13] stringi_1.8.7      xfun_0.52         
 estimability_1.5.1 timechange_0.3.0  \ \## [17] cli_3.6.5         
 withr_3.0.2        magrittr_2.0.3     digest_0.6.37     \ \## [21]
 grid_4.4.0         mvtnorm_1.3-3      rstudioapi_0.17.1  hms_1.1.3        
 \ \## [25] lifecycle_1.0.4    vctrs_0.6.5        evaluate_1.0.3    
 glue_1.8.0        \ \## [29] cellranger_1.1.0   farver_2.1.2      
 abind_1.4-8        rmarkdown_2.29    \ \## [33] tools_4.4.0       
 pkgconfig_2.0.3    htmltools_0.5.8.1 # Overview of files and their
 contents: ### Files and variables #### File:
 Data_1_Temperature_profiles.csv **Description:** Average temperature
 profile (1998-2015) for Davies Reef and the 6-month offset temperature
 profile used in the study. Source: AIMS weather station at Davies Reef
 (18.832° S, 147.635° E), recorded at 4 m depth. ##### Variables * Date: *
 Davies Reef average (1998 - 2015) temperature (C): * 6-month offset
 temperature (C): #### File: Data_2_Temperature_entire.csv
 **Description:** Daily temperature setpoint values applied to
 out-of-season spawning coral systems over the duration of the study #####
 Variables * Local Date: * Out-of-season system temperature (C) setpoints:
 #### File: Data_3_Photoperiod_entire.csv **Description:** Photoperiod data
 used to simulate natural dawn and dusk timings, including civil twilight
 periods, for the out-of-season spawning system. Includes first light and
 last light times for Townsville, Australia, offset by 6 months. #####
 Variables * Local Date: * Lookup Date (Offset 6 months): * First light
 (Civil twilight start): * Phase shifted (4 hours) first light (Civil
 twilight start): * Sunset: * Phase shifted (4 hours) sunset: * Last light
 (Civil twilight end): * Phase shifted (4 hours) last light (Civil twilight
 end): * Phase shift (Hours): #### File: Data_4_Photoperiod_24_hours.csv
 **Description:** Setpoint values for daily light irradiance
 (Photosynthetically Active Radiation [PAR]; µmol photons m⁻² s⁻¹)
 delivered to coral holding systems over a 24-hour period during the
 inshore full moon (20:00, 7 May 2022 – 19:59, 8 May 2022), as shown in
 figure S5. First light and last light times were derived from Data 3 –
 Photoperiod_entire.csv. ##### Variables * Local date/time: * PAR (mmol
 photons m-2 s --1) setpoint: #### File: Data_5_Moonlight_entire.csv
 **Description:** Moonlight settings applied to coral holding tanks,
 including moonrise and moonset times and illuminance (lux) over the
 duration of the study. Note: Moonrise and moonset times are phase-shifted
 by four hours (i.e., advanced by four hours) relative to those listed in
 the file. ##### Variables * Local Date: * Lookup Date (Offset 6 months): *
 Moonrise time: * Moonset time: * Peak lux: * Notes: #### File:
 Data_6_NAFM_TAS_rawdata.xlsx **Description:** Raw spawning time data for
 all coral species used in the out-of-season spawning (OSS) study. Includes
 individual records for nights after full moon (NAFM) and time after sunset
 (TAS) for each spawning event across 2022 and 2023. Dataset supports
 statistical comparisons of temporal spawning synchrony across years and
 against published wild observations (see Baird et al. [30]). #####
 Variables * Species * 2022 * 2023 * Baird.2021 #### File:
 Data_7_NAFM_Rdatatable.csv **Description:** Formatted input dataset for
 statistical analysis of nights after full moon (NAFM), used in the Poisson
 GLM models described in the study. Includes variables for species, dataset
 (2022, 2023, Baird), and transformed NAFM values (with +1 offset to meet
 GLM distributional assumptions). Corresponds to results in supplementary
 tables S8-10. ##### Variables * Species: * Dataset: * NAFM: * Species2: *
 NAFMt: #### File: Data_8_TAS_Rdatatable.csv **Description:** Formatted
 input dataset for statistical analysis of time after sunset (TAS), used in
 the Poisson GLM models described in the study. Includes variables for
 species, dataset (2022, 2023, Baird), and TAS values in minutes.
 Corresponds to results in supplementary tables S9-S11. ##### Variables *
 Species: * Dataset: * TAS: * Species2: * Min: * Hr: * TimeinMin: ####
 File: R_Code_Spawning_Synchrony_Analysis.docx **Description:** R script
 used to analyse coral spawning timing (nights after full moon [NAFM] and
 time after sunset [TAS]) across datasets from 2022, 2023, and published
 wild observations (Baird et al. [30]). The code performs data wrangling,
 assumption checks, and Poisson GLM modelling for each species separately,
 with post-hoc comparisons using estimated marginal means (emmeans).
 Outputs include descriptive statistics, model summaries, and pairwise
 comparisons. Associated input/output files: Data_6_NAFM_TAS_rawdata.xlsx,
 Data_7_NAFM_Rdatatable.csv, and Data_8_TAS_Rdatatable.csv. ### Access
 information Other publicly accessible locations of the data: *
 [https://www.timeanddate.com](https://www.timeanddate.com) *
 [https://weather.aims.gov.au/#/station/4](https://weather.aims.gov.au/#/station/4)