Data from: Controlled out-of-season spawning of reef-forming corals using offset environmental cues

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.

# 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)