Climate change doubles sedimentation-induced coral recruit mortality (NESP TWQ 5.2, AIMS, JCU and AIMS@JCU)

This dataset consists of one spreadsheet, which shows the survival, number of polyps and ability to remove sediment of up to fourteen weeks old Acropora millepora coral recruits while being exposed to three different climate scenarios resembling current climate conditions and conditions expected by mid and end of the century. Coral recruit resilience towards sedimentation was tested by exposing the recruits either five- and ten-weeks following settlement (experiment 1) or only ten-weeks following settlement (experiment 2). Additional tabs show temperature, pCO2 and sediment loads used in the experiment. The study was conducted at the National Sea Simulator.

The aim of this study was to 1) identify lethal concentration thresholds for coral recruits under simultaneous exposure to climate stress (temperature and pCO2) and sedimentation and 2) identify survival mechanisms (i.e., number of polyps, sediment removal capability).

This data will inform the development of water-quality management guidelines, a key aim of NESP project 5.2. The full research report can be found at:
Brunner CA, Uthicke S, Ricardo GF, Hoogenboom MO, Negri AP (2020) Climate change doubles sedimentation-induced coral recruit mortality. Science of the Total Environment, doi.org/10.1016/j.scitotenv.2020.143897

Methods:
Coral recruits of Acropora millepora, a branching coral species abundant in shallow reefs on the Great Barrier Reef, were raised for 14 weeks in ‘current’ and realistic ‘medium’ and ‘high’ climate scenarios (increased temperature and acidification), and were exposed to six environmentally relevant sediment deposition loads typical of flood plumes and dredging operations. The sedimentation events were simulated at different recruit ages: (1) five- and ten-weeks following settlement, and (2) after ten weeks only. One-hour following sediment exposures, sediment removal capabilities were photographically quantified. After a four-week recovery phase, survival and polyp numbers were documented photographically and the data are presented here.

Specific details of the methodology may be found in:
Brunner CA, Uthicke S, Ricardo GF, Hoogenboom MO, Negri AP (2020) Climate change doubles sedimentation-induced coral recruit mortality. Science of the Total Environment, doi.org/10.1016/j.scitotenv.2020.143897

Format:

This dataset consists of one excel workbook xlsx.

Data Dictionary:

Experiment tab
DATE SETTLEMENT - Date of coral larvae settlement, t0
DATE MEASUREMENT - Date survival and polyp numbers were documented
AGE - age in weeks following settlement
EXPERIMENT - (1): Coral recruits were exposed for three days to sedimentation when 5 and 10 weeks old; (2): Coral recruits were exposed for three days to sedimentation when 10 weeks old, see also "date sediment exposure"
CLIMATE SCENARIO - climate scenarios based on manipulated temperature and pCO2, see "Temperatures" and "pCO2" tab for details
ID TANK - identification number of climate controllable aquarium
ID DISC TRAY - identification number of tray where the discs were mounted 
ID DISC - identification number of discs where coral recruits settled on
ID RECRUIT PER DISC - identification number of each recruit on each disc
SEDIMENT (mg / cm²) - sediment load
NUMBER OF POLYPS - number of alive polyps
CORAL ALIVE - (1): coral is alive, (0): coral is dead 
DATE SEDIMENT EXPOSURE - timeframe of sedimentation, NA shows that no sediment was applied in this period
SEDIMENT FREE AFTER 1 HOUR - (1): coral was sediment free 1h after sediment was applied, (0): coral was not sediment free

Temperature tab
DATE - date of temperature measurement
TIME - time of temperature measurement
CORAL AGE (WEEKS AFTER SETTLEMENT) - age in weeks following settlement
CURRENT TEMPERATURE  (°C) - 26.2 – 28.7
MEDIUM TEMPERATURE  (°C) - Current + 0.6
HIGH TEMPERATURE  (°C) - Current + 1.2

pCO2 tab
DATE - date of pCO2 measurement
TIME - time of pCO2 measurement
CORAL AGE (WEEKS AFTER SETTLEMENT) - age in weeks following settlement
CURRENT pCO2 (ppm) - 410 ± 50
MEDIUM pCO2 (ppm) - 680 ± 50
HIGH pCO2 (ppm) - 940 ± 50

Sediment tab
CLIMATE SCENARIO - climate scenarios based on manipulated temperature and pCO2, see "Temperatures" and "pCO2" tab for details
ID TANK -  identification number of climate controllable aquarium
ID DISC TRAY - identification number of tray where the discs were mounted 
ID DISC -identification number of discs where coral recruits settled on
FILTER PREMASS (g) - Weight of 0.4 µm polycarbonate filters
FILTER WITH SEDIMENT (g) - weight of dried (60 °C for greater than or equal to 24 hours) 0.4 µm polycarbonate filters with sediment
SEDIMENT ON FILTER (g) - weight of filter with sediment - filter premass
DISC SURFACE (cm²) - disc surface area based on 2 cm diameter
SEDIMENT INITIALLY APPLIED (mg / cm²) - sediment load at the beginning of the sediment deposition experiment
SEDIMENT REMAINING AFTER THREE DAYS (mg/cm²) - sediment load at the end of the sediment deposition experiment

References:
Brunner CA, Uthicke S, Ricardo GF, Hoogenboom MO, Negri AP (2020) Climate change doubles sedimentation-induced coral recruit mortality. Science of the Total Environment, doi.org/10.1016/j.scitotenv.2020.143897

Data Location:

This dataset is filed in the eAtlas enduring data repository at: data\nesp5\5.2_Cumulative-impacts

Organization: Australian Ocean Data Network