Arnull, J.; Tudhope, A.W.; Wilson, A.M.W.; Ganeshram, R.S.; Hashim, A.S.; Ziyadh, A.M.

Coral bleaching and nutrient responses to elevated temperature and nutrient exposure, Laamu Atoll, Maldives, 2022-2024

https://doi.org/10.5285/c176bbd1-7ad6-43e7-b82b-7c707e95522f
Download/Access
This dataset is under embargo and will be made available by 31 December 2026 at the latest   Find out more »
The data consist of coral bleaching data; coral elemental and isotopic data (of coral host tissue and algal symbionts); coral metric data (size and depth of coral colonies used in experiment); water nutrient data collected next to corals over the experimental period; diffuser weights of fertiliser bags (to help calculate diffusion rates of fertiliser loss) and temperature data (recorded over the experimental windows in-situ and using satellite data).

This dataset contains in-situ experimental information relating two separate nutrient enrichment experiments that were conducted over January - June 2022 and January 2023 - July 2024. The experiments were designed to understand the in-situ bleaching and nutrients responses of corals (Pocillopora spp.) to the interactive effect of elevated temperatures and elevated nutrient concentrations relative to controls. Slow-release agricultural fertilisers were used to elevate local concentrations. In 2022, two types of fertilisers were used (High N = 18-9-10 NPK or High P = 13-13-13 NPK). In 2023-24, the same fertiliser was used (24-7-14 NPK) but at two quantities, medium-N (50-75 g of fertiliser) and high-N (150-200 g of fertiliser) to better understand thresholds. Both experiments were conducted on lagoonal patch reefs in Laamu atoll, Maldives.

The work has been undertaken has been funded by the GCRF-UKRI South Asian Nitrogen Hub and enabled through the University of Edinburgh and Maldivian non-governmental organisation, Maldives Resilient Reefs.
Publication date: 2026-02-25

Format

Comma-separated values (CSV)

Spatial information

Study area
Spatial representation type
Tabular (text)
Spatial reference system
WGS 84

Temporal information

Temporal extent
2022-01-01    to    2024-07-31

Provenance & quality

Coral bleaching data was generated through a visual assessment against University of Queensland coral bleaching cards for each coral during the experiments, where 1 = bleached, 6 = not bleached. The depth and size of each coral were collected at the start of each experiment.

Coral nubbins were collected and separated out into tissue host fraction and algal symbiont fraction. These separate fractions were then analysed for elemental and isotopic compositions (percent carbon, percent nitrogen, δ13C and δ15N).
Water sampling was conducted throughout both experiments and analysed for dissolved inorganic nutrients to confirm enrichment.

Temperature was logged throughout the experiments using HOBO loggers. Any lapse in logger functionality was addressed using supplementary nearby logger data or satellite data.

A record of the fertiliser bags ('diffusers') was kept throughout the experiment to work out weight loss between diffuser changes.

Manual checks have been performed on the data to look for any error in data entry or values reported outside the expected range. This data is heterogenous in nature. Any outliers were then investigated and corrected where appropriate.

Licensing and constraints

This dataset is under embargo and will be made available by 31 December 2026 at the latest   Find out more »

This dataset will be available under the terms of the Open Government Licence

Cite this dataset as:
Arnull, J.; Tudhope, A.W.; Wilson, A.M.W.; Ganeshram, R.S.; Hashim, A.S.; Ziyadh, A.M. (2026). Coral bleaching and nutrient responses to elevated temperature and nutrient exposure, Laamu Atoll, Maldives, 2022-2024. NERC EDS Environmental Information Data Centre. https://doi.org/10.5285/c176bbd1-7ad6-43e7-b82b-7c707e95522f

Correspondence/contact details

Jessica Arnull
University of Edinburgh
 Jessica.Arnull@ed.ac.uk

Authors

Arnull, J.
University of Edinburgh
Tudhope, A.W.
University of Edinburgh
Wilson, A.M.W.
University of Edinburgh
Ganeshram, R.S.
University of Edinburgh
Hashim, A.S.
Maldives Resilient Reefs
Ziyadh, A.M.
Maldives Resilient Reefs

Other contacts

Publisher
NERC EDS Environmental Information Data Centre
 info@eidc.ac.uk
Rights holder
University of Edinburgh

Additional metadata

Topic categories
biota
environment
oceans
INSPIRE theme
Environmental Monitoring Facilities
Keywords
Biodiversity , coastal pollution , coral reef , enrichment , experimental study , Indian Ocean , isotope , nitrogen , Pollution , Water quality
Funding
Natural Environment Research Council Award: NE/S009019/1