Exposure of acute and chronic environmental disturbances affecting coral cover on the GBR from 1992 to 2017 (NESP TWQ 5.2, AIMS)

The dataset consist consists of two (A-B) csv files and one excel file (E). File A shows 1) the absolute percentage total cover and that of specific coral growth forms: Acropora tabular, Acropora branching, other branching species, and massive/submassive species surveyed at 5-9 m depth on 122 reefs (335 reef sites) by the AIMS Long-Term Monitoring Program (LTMP) and Marine Monitoring Program (MMP) between 1992 and 2017 and 2) the long-term average exposure of each reef to variable conditions in water quality (e.g. nutrients, light, salinity, suspended sediments) as well as yearly local (Crown of Thorns Starfish outbreaks-CoTS) and global (heat stress, Cyclones) pressures. File B shows the same cover data mentioned above but only between 2011 and 2017 with the yearly average exposure of each reef to the same environmental conditions mentioned above. The last file E contains the description of the metadata (ie. Data dictionary) for all files (A-D).

Methods:

We used total coral cover and that of four specific coral groupings: Acropora tabular, Acropora branching, other (non-Acropora) branching, and non-Acropora massive/submassive and encrusting species (MSE) to assess the impact of multiple stressors on the Central and Southern GBR regions. Coral cover data for 122 reefs (335 reef sites) were obtained from permanent photo- and video belt transects at 5-9 m depth by the AIMS Long-Term Monitoring Program (LTMP) and Marine Monitoring Program (MMP) between 1992 and 2017.

For the multiple stressors, we collated variables describing the exposure of individual GBR reefs to variable conditions using 1) previous published data (modelled cyclones and heat stress-Degree Heating Weeks (DHW) data from Mathews et al 2019, light at 8m depth from Magno-Canto et al 2019), 2) extracted data from eReefs models specifically for the wet-season (i.e. Dec-April) and at 5m depth (for salinity, chlorophyll a, suspended sediments and Dissolved Inorganic Nitrogen (DIN) https://ereefs.org.au/ereefs), 3) used the AIMS LTMP/MMP datasets (for Crown of Thorns Starfish outbreaks-CoTS) and 4) created new variables based on previous studies (River DIN (DINriv)), from Wolff et al 2018).

Salinity was represented as a cumulative index based on the number of days of exposure to low (