Dataset: Imaging Pulse Amplitude Modulator Fluorometer 2017

Name: Imaging pulse amplitude modulator fluorometer data collected from Acropora cervicornis under different pH and temperature treatments from experiments at Summerland Key, Florida from July to September 2017
Published: 2020-05-19
Keywords: oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.811896.1

Project:

CAREER: Applying phenotypic variability to identify resilient Acropora cervicornis genotypes in the Florida Keys (Resilient Acerv)

Principal Investigator:

Erinn M. Muller (Mote Marine Laboratory, Mote)

BCO-DMO Data Manager:

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2020-05-19

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Imaging pulse amplitude modulator fluorometer data collected from Acropora cervicornis under different pH and temperature treatments from experiments at Summerland Key, Florida from July to September 2017

Abstract:

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Archival Copy

Version Date	Archive	Persistent Identifier (PID)	Date PID Issued
2020-05-19	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.811896.1	2020-05-20

Description

Imaging pulse amplitude modulator fluorometer data collected from Acropora cervicornis under different pH and temperature treatments from experiments at Summerland Key, Florida (24.6616,-81.4538) from July to September 2017.

Methods & Sampling

Corals from different treatment scenarios were IPAMed every month for the duration of the two-month long experiment. All fragments were subjected to a light curve where the initial pulse represents the max Yield after dark acclimation and the subsequent electron transport rate (ETR) values are recorded after the corals were exposed to increasing light intensities over time.

Data Processing Description

We derived three key parameters from the PAM photophysiology data set: maximum yield (mY), maximum electron transport rate (mETR), and the initial slope of the ETR curve (alpha).

PAM dataset parameters: Maximum electron transport rate (mETR) was estimated using a linear search algorithm that used the slopes between adjacent (PAR, ETR) data points to determine the first local critical point (maximum or plateau). The algorithm first searches for three data points between which the slope changes sign. If no sign change is detected, the algorithm then looks for the largest set of two data points between which the slope is less than a user-defined threshold (default is 0.1). In the former case, the middle point is chosen as the (mETR) coordinate, while in the later case the second endpoint is used. If neither search yields a solution, the threshold is increased by 0.01 and the two linear searches are repeated until a solution is found. The slope alpha is calculated with a similar algorithm that searches all PAR levels x such that min(PAR) = 55 < x < mPAR for pairs of points between which the ratio of the local slope to the initial slope (slope between (0,0) and first non-zero datapoint) is less than a user-defined threshold (default is 0.1). If no solution is found, the threshold is increased by 0.01 and the search is repeated. Once a pair of points i and i+1 have been identified, all data points with PAR levels less than that of point i are used to calculate the slope. If the threshold increases to greater than 0.25, the algorithm terminates by returning the slope of all points with PAR < mPAR. Both algorithms return NA when given zero vectors and are both implemented in R.

Data Files

File
IPAM_2017.csv (Comma Separated Values (.csv), 20.62 KB) MD5:aa8535ff1812d629e6934c960af6af39 Primary data file for dataset ID 811896

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1452538

Deployments

None available yet

Instruments

Fluorometer

Supplied Name: Imaging pulse amplitude modulator (IPAM) fluorometer

Supplied Description:

Instrument Type

Generic Name: Fluorometer

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/113/

Generic Description:

A fluorometer or fluorimeter is a device used to measure parameters of fluorescence: its intensity and wavelength distribution of emission spectrum after excitation by a certain spectrum of light. The instrument is designed to measure the amount of stimulated electromagnetic radiation produced by pulses of electromagnetic radiation emitted into a water sample or in situ.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
Tank	identifies the tank number that held the particular coral fragment	unitless	tank
Genotype	identifies the genotype number of the coral animal for each fragment	unitless	sample_type
pH	identifies the treatment pH level: Ambient = 8.1 pH; High CO2 = 7.7 pH	unitless	treatment
Temp	identifies the treatment temperature level: High = 31.5C; Ambient = 27C	unitless	treatment
mYield	change in photosynthetic yield between July and September 2017 after dark acclimation (unitless, but represents the proportion of electrons being used for photosynthesis, potential values range from 0 - 1)	unitless	photosynthesis
mETR	change in the maximum level of electron transport rate between July and September 2017	umol electrons m–2 s–1	ETR
alpha	change in the slope of the electron transport rate between July and September 2017; units represent the change in ETR (umol electrons m–2 s–1 ) over increasing values of PAR	change in ETR over increasing values of PAR	alpha