http://lod.bco-dmo.org/id/dataset/938831
eng; USA
utf8
dataset
Highest level of data collection, from a common set of sensors or instrumentation, usually within the same research project
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
2024-09-25
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Fluorescence spectra from exudation experiments in outdoor tanks with Sargassum samples collected off the coast of Bermuda and in the Sargasso Sea in 2016
2024-09-25
publication
2024-09-25
revision
BCO-DMO Linked Data URI
2024-09-25
creation
http://lod.bco-dmo.org/id/dataset/938831
Michael Gonsior
University of Maryland Center for Environmental Science
principalInvestigator
Neil V. Blough
University of Maryland - College Park
principalInvestigator
Rossana Del Vecchio
University of Maryland - College Park
principalInvestigator
Leanne Powers
University of Maryland Center for Environmental Science
principalInvestigator
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
publisher
Cite this dataset as: Gonsior, M., Blough, N. V., Del Vecchio, R., Powers, L. (2024) Fluorescence spectra from exudation experiments in outdoor tanks with Sargassum samples collected off the coast of Bermuda and in the Sargasso Sea in 2016. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2024-09-25 [if applicable, indicate subset used]. http://lod.bco-dmo.org/id/dataset/938831 [access date]
Dataset Description: <p>See "Related Datasets" section for other datasets from these&nbsp;exudation experiments.</p> Methods and Sampling: <p><em>Sargassum&nbsp;</em>(urn:lsid:marinespecies.org:taxname:144132)<em>&nbsp;</em>was collected during two sampling events in July and in late September/early October 2016, described in detail in a previous study (Powers et al., 2019, Global Biogeochemical Sciences (GBC), <em>33</em>(11), 1423-1439). <em>Sargassum</em> samples were collected using a hand-held net aboard the R/V <em>Sharp</em> in the Sargasso Sea during July 2016 for controlled laboratory exudation experiments. <em>Sargassum</em> was housed onboard in a tank (&lt;3 days) with continuously flowing seawater and transported back to the Chesapeake Biological Laboratory (CBL) immediately upon return to another tank with filtered ambient bay water (adjusted to salinity = 35) that was circulated through a UV treatment system <strong>(</strong>Neotech Aqua Solutions, Inc.) to keep background DOC levels low. <strong>These are exudation experiments are referred to as CBL exudation experiments</strong><strong>.</strong><em> Sargassum</em> samples were also collected aboard the R/V <em>Henry Stommel </em>9 km off the coast of Bermuda in late September 2016 and were transferred to outdoor tanks housed at the Bermuda Institute of Ocean Sciences, with continuously flowing seawater within 2 h of collection. <strong>These exudation experiments are referred to as BDA exudation experiments.</strong> All exudation experiments are described in detail below.</p>
<p><strong>Exudation experiments</strong></p>
<p>Three types of exudation experiments were conducted during this study. One set of experiments was conducted indoors at CBL (listed as “CBL” EXP1 and 2 in the excel sheet). For these experiments, <em>Sargassum</em> subsamples (approximately 100 g wet weight) were rinsed with 24 h UV-treated artificial seawater (Instant Ocean) and transferred to small tanks equipped with a Radion LED lamp (Eco Tech Marine) containing 7 L 24 h UV-treated artificial seawater. Lamps were set for a 14 h day/10 h night cycle and tanks were maintained at 29 °C with Eheim Jager TruTemp Quantum heaters. One tank containing no <em>Sargassum</em> served as a blank and was sampled for dissolved organic carbon (DOC) concentrations, total dissolved nitrogen (TDN) and optical properties. To minimize any stress from transfer, the water was drained and replaced before monitoring DOC/TDN and optical property exudation from the <em>Sargassum</em> samples. CBL EXP3 were the same as EXP1 and 2 with the exception that <em>Sargassum</em> was in mid-senescent conditions (based on visual inspection).</p>
<p>Another set of exudation experiments was conducted in outdoor tanks at the Bermuda Institute of Ocean Sciences (listed as “BDA” EXP1, 3 and 6 in the excel sheet). For these incubations, <em>Sargassum</em> was placed in small tanks containing open ocean seawater within a large tank of continuously flowing seawater. Temperature (°C) and solar intensity (Lux) in the tanks monitored with HOBO® pendant temperature/light data loggers. Temperatures ranged between 26 and 27.5 °C. Tanks were either left uncovered and exposed to full solar irradiation (listed as “UV” or “U” experiments in the excel sheet) or tanks were covered with a Plexiglas cover that had irradiation cut off at 345 nm and UVA (320 to 400 nm) transmission reduced to 65% (listed as “Plexi” or “P” experiments in the excel sheet).</p>
<p>The third set of experiments was performed to investigate the impacts of stress and senescent conditions on the release of DOC/TDN/optical properties by <em>Sargassum </em>(listed as “BDA” EXP 5 and 7 in the excel sheet). The optimal temperature range for pelagic <em>Sargassum </em>sp. is 24 to 30 °C (Hanisak &amp; Samuel, 1987), so one tank was kept indoors and left at 20 °C. All other treatments were conducted outdoors. One tank contained mid-senescent <em>Sargassum</em> and was kept under low light (no direct sunlight) where the temperature did not change from 25 °C over the course of 12 h. The other tanks contained healthy <em>Sargassum</em> but were left outdoors for 12 h in direct sunlight with no temperature control. In these tanks the temperature ranged from 25 °C at the start of the experiment up to 49 °C after 12 h (Table 1). Although 49 °C is unrealistic for the open ocean, similar conditions may be present during annual <em>Sargassum</em> inundation events that occur in coastal environments.</p>
<p>For all experiments, subsamples of tank water were 0.2 µm-filtered (Whatman 25 mm GD/X syringe filters) into clean combusted (500 °C) 40 mL amber glass vials at discrete time points. Optical properties (absorbance and fluorescence spectra) of samples were either analyzed immediately or stored at 4 °C until analysis (within 1 to 10 d of collection). At the same time points, additional samples were acidified to pH 2 using concentrated HCl (Sigma Aldrich 32 %, pura) and analyzed for DOC and TDN concentrations using a Shimadzu TOC-V (see Powers et al., 2019, GBC).&nbsp;</p>
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-1536888 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=1536888
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-1536927 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=1536927
onGoing
Michael Gonsior
University of Maryland Center for Environmental Science
410-326-7245
146 Williams Street
Solomons
MD
20688-3204
USA
gonsior.michael@gmail.com
pointOfContact
Neil V. Blough
University of Maryland - College Park
301-405-0051
Chemistry Bldg 8051 Regents Dr
College Park
MD
20742
USA
neilb@umd.edu
pointOfContact
Rossana Del Vecchio
University of Maryland - College Park
240-502-5381
5825 University Research Ct
College Park
MD
20740
USA
rossdv@umd.edu
pointOfContact
Leanne Powers
University of Maryland Center for Environmental Science
315-470-6854
lcpowers@esf.edu
pointOfContact
asNeeded
Dataset Version: 1
Unknown
EXP
filename
time
V
biomass
DOC_mg_L
DOC_mg_g
TDN_mg_L
TDN_mg_g
A254
A305
A412
a305_V_g
a412_V_g
A254_DOC
A305_DOC
A412_DOC
S300_to_500
Tpeak
Apeak
Cpeak
Horiba Aqualog spectrofluorometer
theme
None, User defined
experiment id
file_name
time_elapsed
volume
wet_weight_biomass
dissolved organic Carbon
Total Dissolved Nitrogen
absorbance
No BCO-DMO term
featureType
BCO-DMO Standard Parameters
Shimadzu Total Organic Carbon Analyzer TOC-VCPH
Spectrometer
instrument
BCO-DMO Standard Instruments
HRS1608
service
Deployment Activity
MidAtlantic
place
Locations
otherRestrictions
otherRestrictions
Access Constraints: none. Use Constraints: Please follow guidelines at: http://www.bco-dmo.org/terms-use Distribution liability: Under no circumstances shall BCO-DMO be liable for any direct, incidental, special, consequential, indirect, or punitive damages that result from the use of, or the inability to use, the materials in this data submission. If you are dissatisfied with any materials in this data submission your sole and exclusive remedy is to discontinue use.
Collaborative Research: Phlorotannins - An Important Source of Marine Chromophoric Dissolved Organic Matter?
https://osprey.bco-dmo.org/project/814753
Collaborative Research: Phlorotannins - An Important Source of Marine Chromophoric Dissolved Organic Matter?
<p>NSF Award Abstract:</p>
<p>Chromophoric dissolved organic matter (CDOM), the sunlight absorbing components in filtered water, is important in the study of marine and freshwater ecosystems as it can be used to trace the mixing of surface waters, as a proxy for carbon cycles, and other biogeochemical processes. Although its importance in ocean studies has been firmly established over the last several decades, sources and structural composition of CDOM within the oceans remains unclear and continues to be a subject of debate. Sargassum, a brown alga, is widely distributed in temperate and subtropical marine waters and may be important source of CDOM to the Sargasso Sea and Gulf of Mexico where Sargassum is abundant. This project will investigate the contribution of macro brown algae-derived compounds to the marine CDOM pool. Results from this study will have implications for the marine carbon cycle and satellite remote sensing of ocean color to assess mixing of surface water masses and biogeochemical processes. The project will provide educational opportunities for a postdoctoral scholar, summertime undergraduate internships (through a local NSF-sponsored Research Experiences for Undergraduates (REU) program), and workshop and research opportunities for local high schools students.</p>
<p>Sources of marine CDOM remain debatable and a comprehensive understanding of its origins, distribution and fate have been difficult. Marine CDOM, and in particular the "humic-like" component, have been suggested to originate from terrestrial sources, primarily lignins. However, recent evidence indicates that the exudation of phlorotannins produced by macro brown algae may contribute significantly to the marine CDOM pool. Phlorotannins, a class of polyphenols that are only found in, and continuously exuded by macro brown algae such as Sargassum, strongly absorb ultraviolet light and may have been underestimated in their contribution to the marine CDOM pool within certain geographic locales. Upon partial oxidation, light absorption by these specific compounds extends into longer wavelengths in the visible creating an absorption spectrum similar to that of lignin. These phlorotannins and their transformation products absorb light that might explain in part the "humic-like" signatures observed in open ocean environments. This study aims to characterize the optical properties and molecular composition of Sargassum-derived CDOM including its aerobic oxidation and photochemical behavior, as well as quantify Sargassum-derived CDOM to better estimate its possible contribution to the CDOM pool in the Sargasso Sea and Gulf of Mexico.</p>
Sargassum DOM
largerWorkCitation
project
eng; USA
oceans
MidAtlantic
2016-06-01
2016-09-01
Mid-Atlantic Bight (July 2016), Sargasso Sea (July and September 2016), Coastal Bermuda (September/October 2016) and Coastal Puerto Rico (Laguna Grande, Fajardo; Las Croabas, Fajardo; Salinas; May/June 2018)
0
BCO-DMO catalogue of parameters from Fluorescence spectra from exudation experiments in outdoor tanks with Sargassum samples collected off the coast of Bermuda and in the Sargasso Sea in 2016
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
http://lod.bco-dmo.org/id/dataset-parameter/939538.rdf
Name: EXP
Units: unitless
Description: <p>exudation experiment number and location </p>
http://lod.bco-dmo.org/id/dataset-parameter/939539.rdf
Name: filename
Units: unitless
Description: <p>Aqualog file name (see Supplemental File "SargassumExudationAbsFluor.zip") for .dat files.</p>
http://lod.bco-dmo.org/id/dataset-parameter/939540.rdf
Name: time
Units: hours
Description: <p>time point sample collected during exp</p>
http://lod.bco-dmo.org/id/dataset-parameter/939541.rdf
Name: V
Units: liters (L)
Description: <p>Tank volume</p>
http://lod.bco-dmo.org/id/dataset-parameter/939542.rdf
Name: biomass
Units: grams (g)
Description: <p>Sargassum biomass (wet weight)</p>
http://lod.bco-dmo.org/id/dataset-parameter/939543.rdf
Name: DOC_mg_L
Units: milligrams per liter (mg/L)
Description: <p>DOC concentration</p>
http://lod.bco-dmo.org/id/dataset-parameter/939544.rdf
Name: DOC_mg_g
Units: milligrams per gram (mg/g)
Description: <p>DOC concentration normalized to V and biomass</p>
http://lod.bco-dmo.org/id/dataset-parameter/939545.rdf
Name: TDN_mg_L
Units: milligrams per liter (mg/L)
Description: <p>TDN concentration</p>
http://lod.bco-dmo.org/id/dataset-parameter/939546.rdf
Name: TDN_mg_g
Units: milligrams per gram (mg/g)
Description: <p>TDN concentration normalized to V and biomass</p>
http://lod.bco-dmo.org/id/dataset-parameter/939547.rdf
Name: A254
Units: unitless
Description: <p>Absorbance at 254 nm</p>
http://lod.bco-dmo.org/id/dataset-parameter/939548.rdf
Name: A305
Units: unitless
Description: <p>Absorbance at 305 nm</p>
http://lod.bco-dmo.org/id/dataset-parameter/939549.rdf
Name: A412
Units: unitless
Description: <p>Absorbance at 412 nm</p>
http://lod.bco-dmo.org/id/dataset-parameter/939550.rdf
Name: a305_V_g
Units: L 1/m 1/g
Description: <p>Absorbance coefficient at 305 nm normalized to volume V and biomass. a305*V/g</p>
http://lod.bco-dmo.org/id/dataset-parameter/939551.rdf
Name: a412_V_g
Units: L 1/m 1/g
Description: <p>Absorbance coefficient at 412 nm normalized to volume V and biomass. a412*V/g</p>
http://lod.bco-dmo.org/id/dataset-parameter/939552.rdf
Name: A254_DOC
Units: L 1/m 1/g
Description: <p>A254/DOC. DOC normalized absorbance at 254 nm (SUVA).</p>
http://lod.bco-dmo.org/id/dataset-parameter/939553.rdf
Name: A305_DOC
Units: L 1/m 1/g
Description: <p>A305/DOC. DOC normalized absorbance at 305 nm.</p>
http://lod.bco-dmo.org/id/dataset-parameter/939554.rdf
Name: A412_DOC
Units: L 1/m 1/g
Description: <p>A412/DOC. DOC normalized absorbance at 412 nm.</p>
http://lod.bco-dmo.org/id/dataset-parameter/939555.rdf
Name: S300_to_500
Units: 1/nm
Description: <p>S(300-500). Spectral slope determined from 300-500 nm.</p>
http://lod.bco-dmo.org/id/dataset-parameter/939556.rdf
Name: Tpeak
Units: RU L/g
Description: <p>Tpeak normalized to volume V and biomass</p>
http://lod.bco-dmo.org/id/dataset-parameter/939557.rdf
Name: Apeak
Units: RU L/g
Description: <p>Apeak normalized to volume V and biomass</p>
http://lod.bco-dmo.org/id/dataset-parameter/939558.rdf
Name: Cpeak
Units: RU L/g
Description: <p>Cpeak normalized to volume V and biomass.</p>
GB/NERC/BODC > British Oceanographic Data Centre, Natural Environment Research Council, United Kingdom
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
https://osprey.bco-dmo.org/dataset/938831/data/download
download
onLine
dataset
<p><em>Sargassum&nbsp;</em>(urn:lsid:marinespecies.org:taxname:144132)<em>&nbsp;</em>was collected during two sampling events in July and in late September/early October 2016, described in detail in a previous study (Powers et al., 2019, Global Biogeochemical Sciences (GBC), <em>33</em>(11), 1423-1439). <em>Sargassum</em> samples were collected using a hand-held net aboard the R/V <em>Sharp</em> in the Sargasso Sea during July 2016 for controlled laboratory exudation experiments. <em>Sargassum</em> was housed onboard in a tank (&lt;3 days) with continuously flowing seawater and transported back to the Chesapeake Biological Laboratory (CBL) immediately upon return to another tank with filtered ambient bay water (adjusted to salinity = 35) that was circulated through a UV treatment system <strong>(</strong>Neotech Aqua Solutions, Inc.) to keep background DOC levels low. <strong>These are exudation experiments are referred to as CBL exudation experiments</strong><strong>.</strong><em> Sargassum</em> samples were also collected aboard the R/V <em>Henry Stommel </em>9 km off the coast of Bermuda in late September 2016 and were transferred to outdoor tanks housed at the Bermuda Institute of Ocean Sciences, with continuously flowing seawater within 2 h of collection. <strong>These exudation experiments are referred to as BDA exudation experiments.</strong> All exudation experiments are described in detail below.</p>
<p><strong>Exudation experiments</strong></p>
<p>Three types of exudation experiments were conducted during this study. One set of experiments was conducted indoors at CBL (listed as “CBL” EXP1 and 2 in the excel sheet). For these experiments, <em>Sargassum</em> subsamples (approximately 100 g wet weight) were rinsed with 24 h UV-treated artificial seawater (Instant Ocean) and transferred to small tanks equipped with a Radion LED lamp (Eco Tech Marine) containing 7 L 24 h UV-treated artificial seawater. Lamps were set for a 14 h day/10 h night cycle and tanks were maintained at 29 °C with Eheim Jager TruTemp Quantum heaters. One tank containing no <em>Sargassum</em> served as a blank and was sampled for dissolved organic carbon (DOC) concentrations, total dissolved nitrogen (TDN) and optical properties. To minimize any stress from transfer, the water was drained and replaced before monitoring DOC/TDN and optical property exudation from the <em>Sargassum</em> samples. CBL EXP3 were the same as EXP1 and 2 with the exception that <em>Sargassum</em> was in mid-senescent conditions (based on visual inspection).</p>
<p>Another set of exudation experiments was conducted in outdoor tanks at the Bermuda Institute of Ocean Sciences (listed as “BDA” EXP1, 3 and 6 in the excel sheet). For these incubations, <em>Sargassum</em> was placed in small tanks containing open ocean seawater within a large tank of continuously flowing seawater. Temperature (°C) and solar intensity (Lux) in the tanks monitored with HOBO® pendant temperature/light data loggers. Temperatures ranged between 26 and 27.5 °C. Tanks were either left uncovered and exposed to full solar irradiation (listed as “UV” or “U” experiments in the excel sheet) or tanks were covered with a Plexiglas cover that had irradiation cut off at 345 nm and UVA (320 to 400 nm) transmission reduced to 65% (listed as “Plexi” or “P” experiments in the excel sheet).</p>
<p>The third set of experiments was performed to investigate the impacts of stress and senescent conditions on the release of DOC/TDN/optical properties by <em>Sargassum </em>(listed as “BDA” EXP 5 and 7 in the excel sheet). The optimal temperature range for pelagic <em>Sargassum </em>sp. is 24 to 30 °C (Hanisak &amp; Samuel, 1987), so one tank was kept indoors and left at 20 °C. All other treatments were conducted outdoors. One tank contained mid-senescent <em>Sargassum</em> and was kept under low light (no direct sunlight) where the temperature did not change from 25 °C over the course of 12 h. The other tanks contained healthy <em>Sargassum</em> but were left outdoors for 12 h in direct sunlight with no temperature control. In these tanks the temperature ranged from 25 °C at the start of the experiment up to 49 °C after 12 h (Table 1). Although 49 °C is unrealistic for the open ocean, similar conditions may be present during annual <em>Sargassum</em> inundation events that occur in coastal environments.</p>
<p>For all experiments, subsamples of tank water were 0.2 µm-filtered (Whatman 25 mm GD/X syringe filters) into clean combusted (500 °C) 40 mL amber glass vials at discrete time points. Optical properties (absorbance and fluorescence spectra) of samples were either analyzed immediately or stored at 4 °C until analysis (within 1 to 10 d of collection). At the same time points, additional samples were acidified to pH 2 using concentrated HCl (Sigma Aldrich 32 %, pura) and analyzed for DOC and TDN concentrations using a Shimadzu TOC-V (see Powers et al., 2019, GBC).&nbsp;</p>
Specified by the Principal Investigator(s)
<div>
<p><strong>DOC and TDN measurements.</strong> Samples were acidified to pH 2 using concentrated HCl (Sigma Aldrich 32 %, pura) and analyzed for dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) concentrations using a Shimadzu TOC-V. Ultrapure water was used as a DOC/TDN blank and potassium hydrogen phthalate and potassium nitrate were used for DOC and TDN standards, respectively.</p>
<p><strong>Optical properties.</strong> For fluorescence and absorbance measurements, samples were transferred to 1 cm quartz fluorescence cuvette and analyzed using a Horiba Aqualog spectrofluorometer. For all time points collected during exudation experiments, raw absorbance spectra (A(λ)) were collected using a Horiba Aqualog at 3 nm intervals between 240 and 600 nm. A(λ) were then converted to Naperian absorption coefficient spectra (a(λ)) using the equation below.</p>
<p>a(λ) = 2.303×A(λ)/L&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (1)</p>
<p>where L (m) is the pathlength of the spectrophotometer cell (0.01 m).</p>
<p>Spectral slope coefficients from 300 to 500 nm (S300-500, nm-1) were determined by fitting a(λ) spectra to the equation</p>
<p>a(λ) = a300*EXP(-S300-500(λ – 300))&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (2)</p>
<p>using a nonlinear curve fitting routine in Matlab 2015a®. A(λ) at various wavelengths was normalized to DOC concentration and the pathlength of the cell to determine changes in the carbon-normalized A(λ) during incubation experiments.</p>
<p>Anorm(λ) = A(λ)/([DOC]×L)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (3)</p>
<p>For instance, specific UV absorbance at 254 nm (SUVA254; m-1 L mg-1), or A(254) normalized to pathlength (m) and DOC concentration (mg L-1).</p>
<p>Fluorescence was recorded from excitation wavelengths 240 to 600 at 3 nm intervals. Emission was recorded from ~243 to 297 nm at fixed ~3.3 nm intervals to created excitation-emission matrix (EEM) spectra. Integration time = 2s. Ultrapure water used as the fluorescence blank and was subtracted from all EEM spectra. Blank corrected EEM spectra were corrected for any inner filter effects using the Aqualog software. All spectra were normalized to the water Raman scattering signal so that all fluorescence data is reported in Raman units (RU). Rayleigh scattering signals were removed from EEM spectra using the Matlab ® (version 2015a) routine outlined previously (Zepp et al. 2004 doi: 10.1016/j.marchem.2004.02.006).</p>
<p>The following additional parameters were also calculated:</p>
<p>Apeak: intensity and location of maximum in the "A" region (ex/em &lt;260 nm/400 – 460 nm)&nbsp; in (intensity x ex. location x em. location) (Coble et al. 1996)</p>
<p>Cpeak: intensity and location of maximum in the "C" region (ex/em 320 – 360 nm/420 – 460 nm) in (intensity x ex. location x em. location) (Coble et al. 1996)</p>
<p>Tpeak: intensity and location of maximum in the "T" region (ex/em &lt;260 nm /320&nbsp; – 350 nm) in (intensity x ex. location x em. location) (Coble et al. 1996)</p>
<p>These parameters (A, C, T peaks) were normalized to tank volume and <em>Sargassum</em> biomass for every time point. Therefore they are reported in RUxL/g.</p>
</div>
Specified by the Principal Investigator(s)
Data from submitted file "Sargassum_Exudation_SPEDOM_DOC_phenols." was imported into the BCO-DMO data system for this dataset. Values "ND" were imported as missing data values.
** Missing data values are displayed differently based on the file format you download. They are blank in csv files, "NaN" in MatLab files, etc.
* Metadata for this dataset was extracted from file DATASET_Sargassum_exudation_bulk_properties.rtf
* Value "#VALUE!" in column S300_to_500 was removed. The line was not removed, just the #VALUE! removed for the row with experiment:"EX3 BDA" time:0V:4.09.
Specified by BCO-DMO Data Managers
asNeeded
7.x-1.1
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
PI Supplied Instrument Name: Instrument Name: Shimadzu Total Organic Carbon Analyzer TOC-VCPH Instrument Short Name:TOC-VCPH Instrument Description: The Shimadzu Total Organic Carbon Analyzer TOC-VCPH is a PC-controlled, total organic carbon analyzer (high-sensitivity model), designed to measure total carbon (TC), inorganic carbon (IC), total organic carbon (TOC), and non-purgeable organic carbon (NPOC); an optional accessory enables the measurement of particulate organic carbon (POC) and total nitrogen (TN) as well. The instrument uses the 680 degrees Celsius combustion catalytic oxidation method to analyze aqueous samples, and optionally solid and gas samples.
Horiba Aqualog spectrofluorometer
Horiba Aqualog spectrofluorometer
PI Supplied Instrument Name: Horiba Aqualog spectrofluorometer Instrument Name: Spectrometer Instrument Short Name:Spectrometer Instrument Description: A spectrometer is an optical instrument used to measure properties of light over a specific portion of the electromagnetic spectrum. Community Standard Description: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0460/
Cruise: HRS1608
HRS1608
R/V Hugh R. Sharp
Community Standard Description
International Council for the Exploration of the Sea
R/V Hugh R. Sharp
vessel
HRS1608
Michael Gonsior
University of Maryland Center for Environmental Science
R/V Hugh R. Sharp
Community Standard Description
International Council for the Exploration of the Sea
R/V Hugh R. Sharp
vessel