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Title Sum-
Institution Dataset ID
     data   graph     files  public Photosynthetic efficiency data from light stress in phytoplankton and dinoflagellate grazing
response experiments from July of 2015 to September of 2018
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The Dataset's Variables and Attributes

Row Type Variable Name Attribute Name Data Type Value
attribute NC_GLOBAL access_formats String .htmlTable,.csv,.json,.mat,.nc,.tsv
attribute NC_GLOBAL acquisition_description String Phytoplankton light stress \u2013 dinoflagellate grazing experiments

General information

Emiliania huxleyi strains were grown in f/50 without added Si, except for
CCMP1516 which was grown in f/2 for experiments D and I and in f/50 otherwise.
All other phytoplankton were grown in f/2 medium without added Si. Most
strains (designated CCMP) were obtained from the National Center for Marine
Algae and Microbiota except Heterocapsa rotundata, which was from the
Norwegian Culture Collection of Algae (NORCCA). Heterotrophic dinoflagellates
Amphidinium longum and Oxyrrhis marina were isolated from marine waters of the
Salish Sea, grown in ciliate medium (Gifford 1985), and maintained on a
mixture of phytoflagellate species. All cultures of any type were grown at a
salinity of 30 and a temperature of 15\u00b0C. Phytoplankton were grown at a
range of low to moderate irradiances, depending on experiment on a 12L:12D
cycle. Heterotrophic dinoflagellates were grown at 10-20 \u00b5mol photons m-2
s-1 on a 12L:12D cycle. Before use in experiments, dinoflagellate predators
were fed only Rhodomonas sp. 755 (A. longum) or Dunaliella tertiolecta (O.
marina) and allowed to consume these prey until they were nearly gone from the

Cells were exposed to experimental light treatments outdoors in a shallow tank
filled with flowing seawater supplied from nearby coastal waters. Temperature
during experiments was monitored at regular intervals with a thermometer
mounted in an unscreened incubation bottle, and ranged from 14-15\u00b0C
except for Exp. A, where it averaged 17\u00b0C. Light (incident
photosynthetically active radiation, or PAR) was measured with a Li-Cor
2\u03c0 sensor, and logged at 5-min intervals so that total experiment light
dose (mol photons m-2) could be computed for specific incubation periods.
Control treatments were incubated in 60-ml polycarbonate bottles screened with
sufficient neutral density screening to approximate growth irradiances. Higher
light exposures were achieved using fewer (or no) layers of neutral density
screening, depending on experiment. Except for Exp. E, which used
polycarbonate bottles only, all high light treatments used 60-ml Teflon
bottles, which are transparent to UV wavelengths. In some experiments high
light treatments included both Teflon (UV-transparent) and polycarbonate (UV-
opaque) bottles, to isolate the effects of UV on protist responses. Bottles
were incubated at ~10 cm depth in the outdoor tank.

Experiments A-F exposed only the phytoplankton prey to the light stress
treatments (\u2018Single_factor_grazing (prey-only)\u2019 data set
dmo.org/dataset/779043\\")). Cultures were divided into incubation bottles
(n=3-5 depending on experiment) and placed in the outdoor tank for 60-120 min.
Photosynthetic efficiency (Fv/Fm) was monitored before cells were taken
outside (t=0) and, after gentle mixing, at 30-min intervals during the
incubations (\u2018FvFm\u2019 data set [https://www.bco-
dmo.org/dataset/779033](\\"https://www.bco-dmo.org/dataset/779033\\")). After
outdoor exposure, phytoplankton were returned to the laboratory and a
subsample from each replicate was added to a corresponding 30-ml polycarbonate
bottle containing heterotrophic dinoflagellate predator A. longum to initiate
predation experiments. The remainder of the phytoplankton culture volume was
placed in an incubator at the culture growth irradiance level, and Fv/Fm
monitored at regular intervals during this recovery period.

Prey concentrations for predation experiments ranged from 5.0 x 103 cells ml-1
for dinoflagellate Heterocapsa rotundata to 5.0 x 104 cells ml-1 for the
various E. huxleyi strains. Prey biomass densities were equivalent for all
prey types, at ~500 \u00b5g C liter-1. Carbon per cell for each phytoplankton
species was estimated from measured cell volumes and published C:volume
conversion factors (Menden-Deuer & Lessard 2000). A. longum concentrations
were ~1-2 x 103 cells ml-1, and O. marina concentration (Exp. I only, see
below) was 260 cells ml-1. For \u2018prey only exposure\u2019 experiments,
predation tests were conducted for 50 min in a laboratory incubator at
15\u00b0C and ~50 \u00b5mol photons m-2 s-1. For \u2018prey and predator
exposure\u2019 experiments, predation tests were conducted for 40-60 min under
either control or high light outdoor illumination conditions. Predation tests
were terminated by adding cells to cold 10% glutaraldehyde and DAPI stain
(final concentrations 0.5% and 0.1 \u00b5g ml-1, respectively). After fixation
overnight in 4\u00b0C and darkness, samples were filtered (3 or 5 \u00b5m
pore-size polycarbonate filters), mounted on slides, and frozen for later
examination by epifluorescence microscopy. UV excitation was used to locate
and identify dinoflagellate predators from the DAPI-induced fluorescence of
their nuclei. Ingested prey were detected using blue light excitation, from
the orange (cryptophyte) or red (all other prey) autofluorescence of the prey
pigments inside the predator food vacuoles Because A. longum uses a peduncle
to feed on cryptophytes, rather than phagocytizing intact cells, the number of
ingested prey per predator cannot be quantified for this predator \u2013 prey
combination. Therefore for all predator and prey types, each micrograzer cell
was scored as \u2018feeding\u2019 or \u2018not feeding\u2019. At least 250
micrograzers per slide were scored; predation intensity was calculated as
fraction of the population feeding (= # micrograzers with ingested prey /
total # micrograzers scored).

Experiments G, H, and I used a matrix design in which predators and prey were
exposed to experimental irradiances separately, then combined in various ways
and predation measured in outdoor irradiance conditions (\u2018Prey and
predator exposure\u2019 data set [https://www.bco-
Cultures of predators and prey were incubated in separate bottles for the
first 1-1.2 h of exposure time. After that, appropriate volumes of prey with
various exposure histories were introduced into predator bottles with various
exposure histories, and those predation tests incubated for an additional
40-60 min at the original predator irradiance level. Fv/Fm was monitored
throughout (\u2018Photosynthetic efficiency\u2019 data set [https://www.bco-
dmo.org/dataset/779033](\\"https://www.bco-dmo.org/dataset/779033\\")), first
in the original phytoplankton-only bottles and then in the remaining
phytoplankton volume after predation tests were initiated, and finally through
a recovery period in the laboratory as described above. At the end of the
predation test period, samples were fixed and slides prepared as described

For more information see Strom et al. (2020).
attribute NC_GLOBAL awards_0_award_nid String 614837
attribute NC_GLOBAL awards_0_award_number String OCE-1434842
attribute NC_GLOBAL awards_0_data_url String http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=1434842 (external link)
attribute NC_GLOBAL awards_0_funder_name String NSF Division of Ocean Sciences
attribute NC_GLOBAL awards_0_funding_acronym String NSF OCE
attribute NC_GLOBAL awards_0_funding_source_nid String 355
attribute NC_GLOBAL awards_0_program_manager String David L. Garrison
attribute NC_GLOBAL awards_0_program_manager_nid String 50534
attribute NC_GLOBAL cdm_data_type String Other
attribute NC_GLOBAL comment String Photosynthetic efficiency data from light stress
PI: Suzanne Strom
Data Version 1: 2019-10-15
attribute NC_GLOBAL Conventions String COARDS, CF-1.6, ACDD-1.3
attribute NC_GLOBAL creator_email String info at bco-dmo.org
attribute NC_GLOBAL creator_name String BCO-DMO
attribute NC_GLOBAL creator_type String institution
attribute NC_GLOBAL creator_url String https://www.bco-dmo.org/ (external link)
attribute NC_GLOBAL data_source String extract_data_as_tsv version 2.3 19 Dec 2019
attribute NC_GLOBAL date_created String 2019-10-11T15:23:55Z
attribute NC_GLOBAL date_modified String 2020-03-19T20:25:59Z
attribute NC_GLOBAL defaultDataQuery String &time<now
attribute NC_GLOBAL doi String 10.26008/1912/bco-dmo.779033.1
attribute NC_GLOBAL infoUrl String https://www.bco-dmo.org/dataset/779033 (external link)
attribute NC_GLOBAL institution String BCO-DMO
attribute NC_GLOBAL instruments_0_acronym String LI-COR Biospherical PAR
attribute NC_GLOBAL instruments_0_dataset_instrument_description String Irradiance measurements: Li-Cor 1400 data logger with 2-pi (cosine) photosynthetically active radiation (PAR) sensor
attribute NC_GLOBAL instruments_0_dataset_instrument_nid String 779036
attribute NC_GLOBAL instruments_0_description String The LI-COR Biospherical PAR Sensor is used to measure Photosynthetically Available Radiation (PAR) in the water column. This instrument designation is used when specific make and model are not known.
attribute NC_GLOBAL instruments_0_instrument_external_identifier String https://vocab.nerc.ac.uk/collection/L22/current/TOOL0074/ (external link)
attribute NC_GLOBAL instruments_0_instrument_name String LI-COR Biospherical PAR Sensor
attribute NC_GLOBAL instruments_0_instrument_nid String 480
attribute NC_GLOBAL instruments_0_supplied_name String Li-Cor 1400 data logger with 2-pi (cosine) photosynthetically active radiation (PAR) sensor
attribute NC_GLOBAL instruments_1_acronym String Fluorometer
attribute NC_GLOBAL instruments_1_dataset_instrument_description String Photosynthetic efficiency measurements: Pulse-Amplitude Modulated Fluorometer: Walz Water PAM
attribute NC_GLOBAL instruments_1_dataset_instrument_nid String 779035
attribute NC_GLOBAL instruments_1_description String 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.
attribute NC_GLOBAL instruments_1_instrument_external_identifier String https://vocab.nerc.ac.uk/collection/L05/current/113/ (external link)
attribute NC_GLOBAL instruments_1_instrument_name String Fluorometer
attribute NC_GLOBAL instruments_1_instrument_nid String 484
attribute NC_GLOBAL instruments_1_supplied_name String Pulse-Amplitude Modulated Fluorometer: Walz Water PAM
attribute NC_GLOBAL keywords String available, bco, bco-dmo, biological, bottle, Bottle_Type, chemical, data, dataset, date, dmo, erddap, experiment, Experiment_ID, FvFm, interval, management, num, Num_Screens, number, oceanography, office, par, photosynthetically, phytoplankton, Phytoplankton_Species, preliminary, radiation, replicate, Replicate_Number, sampling, Sampling_Time, screens, species, time, Time_interval, total, Total_PAR, type
attribute NC_GLOBAL license String https://www.bco-dmo.org/dataset/779033/license (external link)
attribute NC_GLOBAL metadata_source String https://www.bco-dmo.org/api/dataset/779033 (external link)
attribute NC_GLOBAL param_mapping String {'779033': {}}
attribute NC_GLOBAL parameter_source String https://www.bco-dmo.org/mapserver/dataset/779033/parameters (external link)
attribute NC_GLOBAL people_0_affiliation String University of Washington
attribute NC_GLOBAL people_0_affiliation_acronym String UW
attribute NC_GLOBAL people_0_person_name String Suzanne Strom
attribute NC_GLOBAL people_0_person_nid String 50471
attribute NC_GLOBAL people_0_role String Principal Investigator
attribute NC_GLOBAL people_0_role_type String originator
attribute NC_GLOBAL people_1_affiliation String Woods Hole Oceanographic Institution
attribute NC_GLOBAL people_1_affiliation_acronym String WHOI BCO-DMO
attribute NC_GLOBAL people_1_person_name String Amber York
attribute NC_GLOBAL people_1_person_nid String 643627
attribute NC_GLOBAL people_1_role String BCO-DMO Data Manager
attribute NC_GLOBAL people_1_role_type String related
attribute NC_GLOBAL project String Protist signaling
attribute NC_GLOBAL projects_0_acronym String Protist signaling
attribute NC_GLOBAL projects_0_description String Description from NSF proposal:
This proposal arises from the central premise that the oxidative stress response is an emergent property of phototrophic cellular systems, with implications for nearly every aspect of a phytoplankton cell’s life in the upper ocean. Oxidative stress (OS) arises from the uncompensated production of reactive oxygen species (ROS) within a cell, which can occur in response to a myriad of environmental stressors (e.g. nutrient limitation, temperature extremes, toxins, variable light exposure). In addition to the biochemical damage and physiological impairment that OS can cause, the phytoplankton OS response also includes increased net production and extracellular release of ROS, osmolytes, and other compounds that are known or suspected to be potent signals regulating protist behavior. We hypothesize that, through chemical signaling, oxidative stress acts to govern relationships among environmental variability, phytoplankton condition, and protist predation. Our proposed study of these integrated signaling and response processes has three overarching objectives: 1) Create and characterize oxidatively stressed phytoplankton. We will use light stress (variable exposure to visible light and UV) to create oxidatively stressed phytoplankton in the laboratory. Common coastal taxa with contrasting stress responses will be characterized using an array of fluorescent probes, biochemical measurements, and physiological assays. In addition, intracellular production and extracellular release of ROS and the associated chemical signal DMSP will be quantified. Use of Phaeodactylum tricornutum light stress mutants will add an independent means of connecting OS to signal production and predation response. 2) Examine protist predator responses to oxidatively stressed phytoplankton and associated chemical signals. Responses will be investigated by means of manipulation experiments and thorough characterization of associated signal chemistry. Assessment of predator response will be via predation rate measurements and population aggregation/dispersal behaviors in structured columns. 3) Investigate the prevalence of OS, its environmental correlates, and the microzooplankton predation response in the natural waters of a well-characterized local embayment. Application of ROS probes and OS assays to the natural environment and the design of OS manipulation experiments will be informed by the laboratory experiments using local protist species.
Our work will help to elucidate some of the multiple ways in which the OS response can affect phytoplankton fitness, contributing information that can be used to characterize the position of key coastal species along an OS response spectrum. Ultimately such information could be used in trait-based conceptual and numerical models in a manner analogous to cell size and other 'master traits'. Our research will also inform the relatively new and exciting field of chemical signaling in planktonic communities, exploring DMSP- and ROS-based signaling between two of the most significant groups in the plankton, the eukaryotic phytoplankton and their protist predators. Finally, findings will help elucidate the links between environmental stress, phytoplankton response, and predation in planktonic ecosystems. These links relate to central issues in biological oceanography, including the predator-prey interactions that influence bloom demise, and the mechanisms by which protists feed selectively and thereby structure prey communities. The proposed research is a cross-cutting endeavor that unites subjects usually studied in isolation through a novel conceptual framework. Thus the findings have the potential to generate broadly applicable new insights into the ecological and evolutionary regulation of this key trophic link in planktonic food webs.
attribute NC_GLOBAL projects_0_end_date String 2017-08
attribute NC_GLOBAL projects_0_geolocation String Salish Sea: 48.5, -122.75
attribute NC_GLOBAL projects_0_name String Environmental stress and signaling based on reactive oxygen species among planktonic protists
attribute NC_GLOBAL projects_0_project_nid String 614838
attribute NC_GLOBAL projects_0_start_date String 2014-09
attribute NC_GLOBAL publisher_name String Biological and Chemical Oceanographic Data Management Office (BCO-DMO)
attribute NC_GLOBAL publisher_type String institution
attribute NC_GLOBAL sourceUrl String (local files)
attribute NC_GLOBAL standard_name_vocabulary String CF Standard Name Table v55
attribute NC_GLOBAL summary String Fv/Fm (photosynthetic efficiency) data from light stress in phytoplankton and dinoflagellate grazing response experiments from July of 2015 to September of 2018. These data were published in Strom et al. (2020).
attribute NC_GLOBAL title String Photosynthetic efficiency data from light stress in phytoplankton and dinoflagellate grazing response experiments from July of 2015 to September of 2018
attribute NC_GLOBAL version String 1
attribute NC_GLOBAL xml_source String osprey2erddap.update_xml() v1.3
variable Experiment_ID   String  
attribute Experiment_ID bcodmo_name String exp_id
attribute Experiment_ID description String Shows letter (A-I) corresponding to experiment ID system used in Strom et al. (submitted), followed by experiment ID used in Strom lab.
attribute Experiment_ID long_name String Experiment ID
attribute Experiment_ID units String unitless
variable Experiment_Date   String  
attribute Experiment_Date bcodmo_name String date
attribute Experiment_Date description String Calendar date on which experiment was conducted (ISO 8601 format yyyy-mm-dd)
attribute Experiment_Date long_name String Experiment Date
attribute Experiment_Date nerc_identifier String https://vocab.nerc.ac.uk/collection/P01/current/ADATAA01/ (external link)
attribute Experiment_Date source_name String Experiment_Date
attribute Experiment_Date time_precision String 1970-01-01
attribute Experiment_Date units String unitless
variable Phytoplankton_Species   String  
attribute Phytoplankton_Species bcodmo_name String animal_group
attribute Phytoplankton_Species description String Shows species and strain number (CCMP), where available, for phytoplankton used in light stress experiments; see species list for definitions (H. rotundata strain number refers to SCCAP culture collection)
attribute Phytoplankton_Species long_name String Phytoplankton Species
attribute Phytoplankton_Species units String unitless
variable Bottle_Type   String  
attribute Bottle_Type bcodmo_name String bottle
attribute Bottle_Type description String Composition of bottles used for outdoor light exposure; PC = polycarbonate; Tef = Teflon
attribute Bottle_Type long_name String Bottle Type
attribute Bottle_Type units String unitless
variable Num_Screens   byte  
attribute Num_Screens _FillValue byte 127
attribute Num_Screens actual_range byte 0, 7
attribute Num_Screens bcodmo_name String sample_descrip
attribute Num_Screens description String Number of neutral density screen layers used to wrap bottles during outdoor exposure period
attribute Num_Screens long_name String Num Screens
attribute Num_Screens units String unitless
variable Total_PAR   float  
attribute Total_PAR _FillValue float NaN
attribute Total_PAR actual_range float 0.0897, 9.18
attribute Total_PAR bcodmo_name String PAR
attribute Total_PAR description String Total (cumulative) dose of photosynthetically active radiation received by the sample during the outdoor incubation period
attribute Total_PAR long_name String Total PAR
attribute Total_PAR units String mol photons m-2
variable Time_interval   String  
attribute Time_interval bcodmo_name String sample_descrip
attribute Time_interval description String Designates whether the reported data were collected during the outdoor light exposure period (‘exposure’), or during the indoor, low light recovery period (‘recovery’)
attribute Time_interval long_name String Time Interval
attribute Time_interval units String unitless
variable Sampling_Time   short  
attribute Sampling_Time _FillValue short 32767
attribute Sampling_Time actual_range short 0, 1568
attribute Sampling_Time bcodmo_name String time_elapsed
attribute Sampling_Time description String Shows the time (min) after initiation of exposure period when Fv/Fm samples were collected from incubation bottles.
attribute Sampling_Time long_name String Sampling Time
attribute Sampling_Time nerc_identifier String https://vocab.nerc.ac.uk/collection/P01/current/ELTMZZZZ/ (external link)
attribute Sampling_Time units String count
variable Replicate_Number   byte  
attribute Replicate_Number _FillValue byte 127
attribute Replicate_Number actual_range byte 1, 4
attribute Replicate_Number bcodmo_name String replicate
attribute Replicate_Number colorBarMaximum double 100.0
attribute Replicate_Number colorBarMinimum double 0.0
attribute Replicate_Number description String Identifies an individual replicate bottle
attribute Replicate_Number long_name String Replicate Number
attribute Replicate_Number units String unitless
variable FvFm   float  
attribute FvFm _FillValue float NaN
attribute FvFm actual_range float -0.035, 0.784
attribute FvFm bcodmo_name String Fv2Fm
attribute FvFm description String Photosynthetic efficiency Fv/Fm (= variable fluorescence/maximum fluorescence) as measured using a Walz Water PAM fluorometer after 20 min dark acclimation at 15°C
attribute FvFm long_name String FV FM
attribute FvFm units String dimensionless

The information in the table above is also available in other file formats (.csv, .htmlTable, .itx, .json, .jsonlCSV1, .jsonlCSV, .jsonlKVP, .mat, .nc, .nccsv, .tsv, .xhtml) via a RESTful web service.

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