Dataset: recruit_survival
Deployment: lab_Edmunds_NMMBA

Coral recruit survivorship in variable CO2 conditions

Lead Principal Investigator:

Peter J. Edmunds (California State University Northridge, CSUN)

Student:

Aaron M. Dufault (California State University Northridge, CSUN)

BCO-DMO Data Manager:

Danie Kinkade (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Moorea Coral Reef Long-Term Ecological Research site (MCR LTER)

The ecophysiological basis of the response of coral larvae and early life history stages to global climate change (Climate_Coral_Larvae)

Current State:

Preliminary and in progress

Data URL:

https://www.bco-dmo.org/dataset-deployment/516533/data

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Description

Manipulative studies have demonstrated that ocean acidification (OA) is a threat to coral reefs, yet no experiments have employed diurnal variations in pCO2 that are ecologically relevant to many shallow reefs. Two experiments were conducted to test the response of coral recruits (less than 6 days old) to diurnally oscillating pCO2; one exposing recruits for 3 days to ambient (440 uatm), high (663 uatm) and diurnally oscillating pCO2 on a natural phase (420–596 uatm), and another exposing recruits for 6 days to ambient (456 uatm), high (837 uatm) and diurnally oscillating pCO2 on either a natural or a reverse phase (448–845 uatm).

These data are published in Dufault et al. (2012), Proc. R. Soc. B. doi:10.1098/rspb.2011.2545

Related Datasets:

recruit_growth_weight
recruit_growth_area
recruit_seawater_chemistry

Methods & Sampling

Dataset acquisition description

Larvae were obtained from brooding colonies coral S. caliendrum collected from 5 to 7 m deep on Hobihu Reef, Nanwan Bay, in March and June of 2010, placed into individual flow-through seawater tanks. Overflow water from each tank passed through mesh-lined (110 mm) cups that captured larvae. Following collection, larvae were settled onto clean pre-weighed glass microscope coverslips. Coverslips with coral recruits (n=18: experiment I; n=36: experiment II) were assigned randomly to the pCO2 treatments.

In experiment I, treatments consisted of steady ambient pCO2, steady high pCO2 and diurnally oscillating pCO2 on a natural phase; this design was augmented in experiment II by including a diurnally oscillating pCO2 on a reverse phase.

Upon completion of the experiments, coverslips with coral recruits were placed in bleach (6% NaOCl) for 8 h to dissolve the tissue on the small corals and leave behind the CaCO3 skeleton. Coverslips were then rinsed with deionized water to remove the bleach and air-dried for 24 h at approximately 278C. Calcification was measured using the summed weight of the CaCO3 deposited by recruits on each coverslip and also as the planar area of the basal plate of each recruit. Coverslips without recruits but subjected to identical treatments served as procedural controls, and these did not change in weight in either experiment. In experiment I, the change in weight of each coverslip was divided by the number of corallites to provide a mean weight that was used as a statistical replicate. As some (approx. 5%) recruits died during the experiment, this technique slightly underestimated calcification.To remove this bias in experiment II, only recruits alive at the end of the experiment were used for growth measurements.

To evaluate survivorship during experiment II, recruits were photographed (Canon 40D, 10 megapixel resolution) every 2 days throughout the 6-day experiment. Images were used to score the recruits as alive or dead based on the presence of tissue, which is easily discernable from photographs. Survivorship was not measured in experiment I owing to logistical constraints.

For detailed description of methods, see Dufault et al. (2012), Proc. R. Soc. B. doi:10.1098/rspb.2011.2545

Data Processing Description

Dataset Processing Description

To analyse survivorship in experiment II, a Kaplan–Meier (KM) product-limit analysis was used [33]. For this analysis, the probability of individual recruits surviving is assumed to be independent of all other recruits, and because KM analyses cannot accommodate nested experimental designs, replicate corallites were pooled within each treatment. Survival was analysed using the statistical program JMP (v. 9.0.2, 2010, SAS Institute Inc.) and a log-rank test was used to test for differential survival among treatments.

For detailed description of processing see Dufault et al. (2012), Proc. R. Soc. B. doi:10.1098/rspb.2011.2545

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-0844785	NSF Division of Ocean Sciences

Instruments

Camera

Supplied Name: camera

Supplied Description:

Canon 40D, 10 megapixel resolution was used to photograph coral recruits.

Instrument Type

Generic Name: Camera

Acronym: camera

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/311/

Generic Description:

All types of photographic equipment including stills, video, film and digital systems.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
laboratory	Laboratory where experiments were conducted.	unitless	laboratory
lat	Latitude component of geographic position where experiments were conducted.	decimal degrees	lat
lon	Longitude component of geographic position where experiments were conducted.	decimal degrees	lon
coverslip	Unique coverslip the coral was settled upon.	dim	sample
treatment_CO2	Individual CO2 treatment (A=ambient, H=High, D=Diurnal, DX=Reverse-phase Diurnal). Originally reported as "CO2".	dimensionless	treatment
tank	Unique tank the coverslips with settled corals were placed in (a decimal number represents 2 tanks used for the diurnal treatments - corals were placed in the first tank during the day (1st number) and into the second tank at night (2nd number), eg Tank 1.8= tank 1 during day, tank 8 at night).	dimensionless	tank
month	Month of coral colony collection.	dimensionless	month
year	Year of coral colony collection.		year
count_initial	Number of alive corals counted on day 0.	dimensionless	count
count_day2	Number of alive corals counted on day 2.	dimensionless	count
count_day4	Number of alive corals counted on day 4.	dimensionless	count
count_day6	Number of alive corals counted on day 6.	dimensionless	count

Database

Contribute Data

Dataset: recruit_survival
Deployment: lab_Edmunds_NMMBA

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: recruit_survivalDeployment: lab_Edmunds_NMMBA

Dataset acquisition description

Dataset Processing Description

Dataset: recruit_survival
Deployment: lab_Edmunds_NMMBA