http://lod.bco-dmo.org/id/dataset/2545
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
2010-06-16
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Carbon biomass mesozooplankton estimates from MOCNESS oblique tows from R/V Thomas G. Thompson TT043, TT045, TT050 cruises in the Arabian Sea in 1995 (U.S. JGOFS Arabian Sea project)
1996-04-23
publication
1996-04-23
revision
BCO-DMO Linked Data URI
1996-04-23
creation
http://lod.bco-dmo.org/id/dataset/2545
Michael R. Roman
University of Maryland Center for Environmental Science
principalInvestigator
Dr Anne Gauzens
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: Roman, M. R., Gauzens, A. (1996) Carbon biomass mesozooplankton estimates from MOCNESS oblique tows from R/V Thomas G. Thompson TT043, TT045, TT050 cruises in the Arabian Sea in 1995 (U.S. JGOFS Arabian Sea project). Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version April 23, 1996 ) Version Date 1996-04-23 [if applicable, indicate subset used]. http://lod.bco-dmo.org/id/dataset/2545 [access date]
Carbon biomass mesozooplankton, MOCNESS oblique tows Dataset Description: <p>Carbon biomass mesozooplankton, MOCNESS oblique tows</p> Methods and Sampling: <p>See Platform deployments for cruise specific documentation</p>
Funding provided by National Science Foundation (NSF) Award Number: unknown Arabian Sea NSF
completed
Michael R. Roman
University of Maryland Center for Environmental Science
410-221-8425
Horn Point Laboratory 2020 Horns Point Road
Cambridge
MD
21613
USA
roman@umces.edu
pointOfContact
Dr Anne Gauzens
University of Maryland Center for Environmental Science
gauzens@hpl.umces.edu
pointOfContact
asNeeded
Dataset Version: April 23, 1996
Unknown
sta
sta_std
event
depth_begin
depth_end
depth_mid
mzp_C_64_200
mzp_C_gt_200
MOCNESS.25
theme
None, User defined
No BCO-DMO term
event
depth_mid
featureType
BCO-DMO Standard Parameters
MOCNESS.25
instrument
BCO-DMO Standard Instruments
TT043
TT045
TT050
service
Deployment Activity
U.S. JGOFS Arabian Sea
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.
U.S. Joint Global Ocean Flux Study
http://usjgofs.whoi.edu/
U.S. Joint Global Ocean Flux Study
The United States Joint Global Ocean Flux Study was a national component of international JGOFS and an integral part of global climate change research.
The U.S. launched the Joint Global Ocean Flux Study (JGOFS) in the late 1980s to study the ocean carbon cycle. An ambitious goal was set to understand the controls on the concentrations and fluxes of carbon and associated nutrients in the ocean. A new field of ocean biogeochemistry emerged with an emphasis on quality measurements of carbon system parameters and interdisciplinary field studies of the biological, chemical and physical process which control the ocean carbon cycle. As we studied ocean biogeochemistry, we learned that our simple views of carbon uptake and transport were severely limited, and a new "wave" of ocean science was born. U.S. JGOFS has been supported primarily by the U.S. National Science Foundation in collaboration with the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration, the Department of Energy and the Office of Naval Research. U.S. JGOFS, ended in 2005 with the conclusion of the Synthesis and Modeling Project (SMP).
U.S. JGOFS
largerWorkCitation
program
U.S. JGOFS Arabian Sea
http://usjgofs.whoi.edu/research/arabian.html
U.S. JGOFS Arabian Sea
<p>The U.S. Arabian Sea Expedition which began in September 1994 and ended in January 1996, had three major components: a U.S. JGOFS Process Study, supported by the National Science Foundation (NSF); Forced Upper Ocean Dynamics, an Office of Naval Research (ONR) initiative; and shipboard and aircraft measurements supported by the National Aeronautics and Space Administration (NASA). The Expedition consisted of 17 cruises aboard the R/V Thomas Thompson, year-long moored deployments of five instrumented surface buoys and five sediment-trap arrays, aircraft overflights and satellite observations. Of the seventeen ship cruises, six were allocated to repeat process survey cruises, four to SeaSoar mapping cruises, six to mooring and benthic work, and a single calibration cruise which was essentially conducted in transit to the Arabian Sea.</p>
Arabian Sea
largerWorkCitation
project
eng; USA
oceans
U.S. JGOFS Arabian Sea
1996-04-23
Arabian Sea
0
BCO-DMO catalogue of parameters from Carbon biomass mesozooplankton estimates from MOCNESS oblique tows from R/V Thomas G. Thompson TT043, TT045, TT050 cruises in the Arabian Sea in 1995 (U.S. JGOFS Arabian Sea 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
http://lod.bco-dmo.org/id/dataset-parameter/9721.rdf
Name: sta
Units: unknown
Description: <p>station number</p>
http://lod.bco-dmo.org/id/dataset-parameter/9722.rdf
Name: sta_std
Units: unknown
Description: <p>Arabian Sea standard station identifier</p>
http://lod.bco-dmo.org/id/dataset-parameter/9723.rdf
Name: event
Units: dimensionless
Description: <p>event number, from event log</p>
http://lod.bco-dmo.org/id/dataset-parameter/9724.rdf
Name: depth_begin
Units: meters
Description: <p>depth sample collection started</p>
http://lod.bco-dmo.org/id/dataset-parameter/9725.rdf
Name: depth_end
Units: meters
Description: <p>depth sample collection stopped</p>
http://lod.bco-dmo.org/id/dataset-parameter/9726.rdf
Name: depth_mid
Units: meters
Description: <p>mid point of sample collection depth range</p>
http://lod.bco-dmo.org/id/dataset-parameter/9727.rdf
Name: mzp_C_64_200
Units: mmol C m^2
Description: <p>carbon biomass of mesozooplankton in size fraction 64-200 micrometers</p>
http://lod.bco-dmo.org/id/dataset-parameter/9728.rdf
Name: mzp_C_gt_200
Units: mmol C m^2
Description: <p>carbon biomass of mesozooplankton in size fraction greater than 200 micrometers</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
4672
https://datadocs.bco-dmo.org/file/2GN3n08sKPoDgm/mesozoo_moc_TT043.csv
mesozoo_moc_TT043.csv
version April 23, 1996
Mesozooplankton carbon biomass (CHN analysis)
Michael Roman, Anne Gauzens
Process 1, Arabian Sea Cruise TN043
MOCNESS 1/4 Sampler - oblique tows from 200m to surface
download
4058
https://datadocs.bco-dmo.org/file/1VN2my6HnP99jN/mesozoo_moc_TT045.csv
mesozoo_moc_TT045.csv
version April 23, 1996
Mesozooplankton carbon biomass (CHN analysis)
Michael Roman, Anne Gauzens
Process 2, Arabian Sea Cruise TN045
MOCNESS 1/4 Sampler - oblique tows from 200m to surface
download
3561
https://datadocs.bco-dmo.org/file/OJDO1wgCNo3OVn/mesozoo_moc_TT050.csv
mesozoo_moc_TT050.csv
version April 23, 1996
Mesozooplankton carbon biomass (CHN analysis)
Michael Roman, Anne Gauzens
Process 5, Arabian Sea Cruise TN050 - submitted by Michael Roman
MOCNESS 1/4 Sampler - oblique tows from 200m to surface
download
https://osprey.bco-dmo.org/dataset/2545/data/download
download
onLine
dataset
<p>See Platform deployments for cruise specific documentation</p>
from Cruise: TT043 <pre>
<strong>PI:</strong> Michael Roman
<strong>of:</strong> Horn Point Environmental Laboratory
<strong>dataset:</strong> Carbon biomass mesozooplankton, MOCNESS oblique tows
<strong>dates:</strong> January 12, 1995 to January 30, 1995
<strong>location:</strong> N: 19.1744 S: 9.9994 W: 58.0005 E: 68.7449
<strong>project/cruise:</strong> Process 1 TN043 Winter monsoon in the Arabian Sea
<strong>ship:</strong> R/V Thomas Thompson
</pre>
<h1>Mesozooplankton Protocols</h1>
<p><strong>Hans Dam and Michael Roman</strong></p>
<p> </p>
<hr />
<h4>Mesozooplankton Biomass</h4>
<p>Mesozooplankton (> 64 µm) were collected from day/night pairs of tows with a 0.25 m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_2.gif" />-mouth area MOCNESS equipped with nine nets with a 7:1, mouth:length ratio (Wiebe <em>et al.</em>, 1985). Transmission by underwater sensors on the MOCNESS through conducting cable to the deck yielded output of fluorescence, temperature, conductivity, depth, frame angle, volume filtered, and net closing response at 1-s intervals. Oblique tows were taken from 1000 m and 200 m to the surface. Eight depth strata were sampled on both shallow and deep tows:</p>
<p> </p>
<pre>
0 - 10 m 0 - 20 m
10 - 20 m 20 - 40 m
20 - 40 m 40 - 100 m
40 - 60 m 100 - 200 m
60 - 80 m 200 - 400 m
80 - 100 m 400 - 600 m
100 - 150 m 600 - 800 m
150 - 200 m 800 - 1000 m
</pre>
<p>Descent rates of the MOCNESS were generally between 40 and 50 m min<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> and ascent speeds between 10 and 20 m min<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />. The MOCNESS was towed at a ship speed of 2 kt which resulted in a net angle of near 45 <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" />.</p>
<p>On board ship, the contents of each net were split in half with a Folsom Plankton Splitter. One half of the sample was preserved in 4% buffered (Sodium Borate) Formalin. The remaining half of the sample was gently wet-sieved through a 2.0 mm mesh to remove gelatinous zooplankton and micronekton (not caught quantitatively by 0.25 m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_2.gif" /> MOCNESS). The portion passing through this mesh was wet-sieved further through 1.0 mm, 0.5 mm and 0.2 mm meshes. This procedure yielded four different size classes: 2.0-1.0 mm; 1.0-0.5 mm; 0.5-0.2 mm and 0.2-0.064 mm. The samples caught on these size fractions were diluted and thoroughly mixed in a known volume of filtered seawater and duplicate aliquots, drawn with a Hensen-Stempel pipette, filtered onto precombusted GF/D filters and rinsed with a small amount of distilled water to get rid of salt. Filters were dried at 60 <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> C. Organic carbon and nitrogen for each filter were measured with a Model 440 Control Equipment CHN analyzer at the Horn Point Laboratory of the University of Maryland. The average error associated with subsampling the zooplankton catch for carbon analysis was 16% (standard deviation/mean). Zooplankton biomass of the different size fractions as well as the amount of total (> 64 µm) mesozooplankton is expressed as mg C m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_3.gif" /> or mg C m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-2.gif" />(integrated).</p>
from Cruise: TT045 <pre>
<strong>PI:</strong> Michael Roman
<strong>of:</strong> Horn Point Environmental Laboratory<strong>
dataset:</strong> Carbon biomass mesozooplankton, MOCNESS oblique tows
<strong>dates:</strong> March 19, 1995 to April 06, 1995
<strong>location:</strong> N: 19.1451 S: 10.0063 W: 58.0007 E: 67.1653
<strong>project/cruise:</strong> Process 2 TN045 Inter-monsoon in the Arabian Sea
<strong>ship:</strong> R/V Thomas Thompson
</pre>
<h1>Mesozooplankton Protocols</h1>
<p><strong>Hans Dam and Michael Roman</strong></p>
<p> </p>
<hr />
<h4>Mesozooplankton Biomass</h4>
<p>Mesozooplankton (> 64 �m) were collected from day/night pairs of tows with a 0.25 m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_2.gif" />-mouth area MOCNESS equipped with nine nets with a 7:1, mouth:length ratio (Wiebe <em>et al.</em>, 1985). Transmission by underwater sensors on the MOCNESS through conducting cable to the deck yielded output of fluorescence, temperature, conductivity, depth, frame angle, volume filtered, and net closing response at 1-s intervals. Oblique tows were taken from 1000 m and 200 m to the surface. Eight depth strata were sampled on both shallow and deep tows:</p>
<p> </p>
<pre>
0 - 10 m 0 - 20 m
10 - 20 m 20 - 40 m
20 - 40 m 40 - 100 m
40 - 60 m 100 - 200 m
60 - 80 m 200 - 400 m
80 - 100 m 400 - 600 m
100 - 150 m 600 - 800 m
150 - 200 m 800 - 1000 m
</pre>
<p>Descent rates of the MOCNESS were generally between 40 and 50 m min<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> and ascent speeds between 10 and 20 m min<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />. The MOCNESS was towed at a ship speed of 2 kt which resulted in a net angle of near 45 <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" />.</p>
<p>On board ship, the contents of each net were split in half with a Folsom Plankton Splitter. One half of the sample was preserved in 4% buffered (Sodium Borate) Formalin. The remaining half of the sample was gently wet-sieved through a 2.0 mm mesh to remove gelatinous zooplankton and micronekton (not caught quantitatively by 0.25 m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_2.gif" /> MOCNESS). The portion passing through this mesh was wet-sieved further through 1.0 mm, 0.5 mm and 0.2 mm meshes. This procedure yielded four different size classes: 2.0-1.0 mm; 1.0-0.5 mm; 0.5-0.2 mm and 0.2-0.064 mm. The samples caught on these size fractions were diluted and thoroughly mixed in a known volume of filtered seawater and duplicate aliquots, drawn with a Hensen-Stempel pipette, filtered onto precombusted GF/D filters and rinsed with a small amount of distilled water to get rid of salt. Filters were dried at 60 <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> C. Organic carbon and nitrogen for each filter were measured with a Model 440 Control Equipment CHN analyzer at the Horn Point Laboratory of the University of Maryland. The average error associated with subsampling the zooplankton catch for carbon analysis was 16% (standard deviation/mean). Zooplankton biomass of the different size fractions as well as the amount of total (> 64 �m) mesozooplankton is expressed as mg C m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_3.gif" /> or mg C m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-2.gif" />(integrated).</p>
from Cruise: TT050 <pre>
<strong>PI:</strong> Michael Roman
<strong>of:</strong> Horn Point Environmental Laboratory
<strong>dataset:</strong> Carbon biomass mesozooplankton, MOCNESS oblique tows
<strong>dates:</strong> August 23, 1995 to September 11, 1995
<strong>location:</strong> N: 19.1776 S: 9.9603 W: 58.0268 E: 67.2369
<strong>project/cruise:</strong> Process 5 TN050 Summer monsoon in the Arabian Sea
<strong>ship:</strong> R/V Thomas Thompson
</pre>
<h1>Mesozooplankton Protocols</h1>
<p><strong>Hans Dam and Michael Roman</strong></p>
<p> </p>
<hr />
<h4>Mesozooplankton Biomass</h4>
<p>Mesozooplankton (> 64 µm) were collected from day/night pairs of tows with a 0.25 m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_2.gif" />-mouth area MOCNESS equipped with nine nets with a 7:1, mouth:length ratio (Wiebe <em>et al.</em>, 1985). Transmission by underwater sensors on the MOCNESS through conducting cable to the deck yielded output of fluorescence, temperature, conductivity, depth, frame angle, volume filtered, and net closing response at 1-s intervals. Oblique tows were taken from 1000 m and 200 m to the surface. Eight depth strata were sampled on both shallow and deep tows:</p>
<p> </p>
<pre>
0 - 10 m 0 - 20 m
10 - 20 m 20 - 40 m
20 - 40 m 40 - 100 m
40 - 60 m 100 - 200 m
60 - 80 m 200 - 400 m
80 - 100 m 400 - 600 m
100 - 150 m 600 - 800 m
150 - 200 m 800 - 1000 m
</pre>
<p>Descent rates of the MOCNESS were generally between 40 and 50 m min<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> and ascent speeds between 10 and 20 m min<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />. The MOCNESS was towed at a ship speed of 2 kt which resulted in a net angle of near 45 <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" />.</p>
<p>On board ship, the contents of each net were split in half with a Folsom Plankton Splitter. One half of the sample was preserved in 4% buffered (Sodium Borate) Formalin. The remaining half of the sample was gently wet-sieved through a 2.0 mm mesh to remove gelatinous zooplankton and micronekton (not caught quantitatively by 0.25 m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_2.gif" /> MOCNESS). The portion passing through this mesh was wet-sieved further through 1.0 mm, 0.5 mm and 0.2 mm meshes. This procedure yielded four different size classes: 2.0-1.0 mm; 1.0-0.5 mm; 0.5-0.2 mm and 0.2-0.064 mm. The samples caught on these size fractions were diluted and thoroughly mixed in a known volume of filtered seawater and duplicate aliquots, drawn with a Hensen-Stempel pipette, filtered onto precombusted GF/D filters and rinsed with a small amount of distilled water to get rid of salt. Filters were dried at 60 <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> C. Organic carbon and nitrogen for each filter were measured with a Model 440 Control Equipment CHN analyzer at the Horn Point Laboratory of the University of Maryland. The average error associated with subsampling the zooplankton catch for carbon analysis was 16% (standard deviation/mean). Zooplankton biomass of the different size fractions as well as the amount of total (> 64 µm) mesozooplankton is expressed as mg C m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_3.gif" /> or mg C m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-2.gif" />(integrated).</p>
Specified by the Principal Investigator(s)
<p>Analysis methodology referenced in:<br />
Roman, M.R. et al, Zooplankton variability on the equator at 140W during the JGOFS EqPac Study. Deep Sea Research II, 42(2-3) : 673-693, 1995</p>
<p><strong>Mesozooplankton Grazing - Isotope Method</strong></p>
<p>Measurements of grazing rates by the radioisotope uptake technique were done day and night, immediately following the MOCNESS tows, in short term, <em>in situ</em> incubations at 1, 10, 30, 50, 70 and 90 m (Roman and Rublee, 1981). Five-liter Plexiglas chambers (General Oceanics) with 64 µm-mesh covering the bottom were lowered 10 m past the desired depths and then raised to concentrate zooplankton in the chambers. A messenger triggered the close of the bottles and released the radioisotope tracers (25 µCi l<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> of methyl<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-3.gif" />H-thymidine, &gt; 75 Ci mmol<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> and 50 µCi l<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> Na<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_2.gif" /> <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_14.gif" />CO<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_3.gif" />, 55.0 Ci mmol<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> ) into the chambers. After a 45-minute incubation on the hydrowire, the chambers were retrieved, zooplankton collected on nested 200 and 64 µm sieves. The zooplankton were rinsed (filtered seawater, 10% HCl and deionized water) onto preweighed 12 µm pore-size Nuclepore filters and dried. Using a dissecting microscope, visible detritus and phytoplankton were removed with a sable brush. The filters were weighed and the weight-specific dpm of the isotopes were measured. Zooplankton carbon was assumed to be 40% of their dry weight to calculate the dpm mg C<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> of the zooplankton. The labelled particulate matter (&lt; 64 µm) was collected on 0.2 µm and 2.0 µm pore-size Nuclepore filters to determine the specific activity of the particulate matter. We derived weight-specific corrections for the absorption and adsorption of the isotopes in shipboard experiments using both filtered seawater and time-0 controls. These corrections were generally less than 10% of experimental values. The isotope activity of the labelled particulate matter (&gt; 2 µm) and zooplankton were used to calculate zooplankton filtration rates, F = liters filtered. mg zooplankton C<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> h<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />, after Daro (1978). The grazing impact of the zooplankton community, expressed as liters filtered m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-3.gif" /> h<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />, was calculated as the product of the weight-specific filtration rate determined from the <em>in situ</em> incubations and the zooplankton biomass in the same depth interval determined immediately prior to the grazing incubation. We used both <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_14.gif" />C bicarbonate and [methyl] <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-3.gif" />H thymidine to estimate the filtration rates of mesozooplankton upon autotrophs (phytoplankton and protozoa that consumed phytoplankton) and heterotrophs (free-living and attached bacteria and protozoa that have consumed bacteria).</p>
<p><strong>Mesozooplankton Grazing - Gut Fluorescence Method</strong></p>
<p>Zooplankton were collected day and night, immediately preceding MOCNESS tows, from vertical tows with opening-closing, 3/4 meter-Puget Sound nets equipped with 200 µm mesh and solid cod ends. Nets were towed to sample depth strata similar to those sampled by the MOCNESS in the upper 120 m. Three depth strata sampled were: 0-20 m, 20-60 m and 60-120 m. The contents of each net was immediately sieved under dim light red light to yield three size fractions: 2.0-1.0 mm; 1.0-0.5 mm and 0.5-0.2 mm. Each fraction was immediately filtered onto a glass fiber filter (GF/A) and frozen at -20<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> C. This procedure took about 5 min. Samples were analyzed in the laboratory ashore. We employed a modification of the procedure described by Dam and Peterson (1988). Thawed samples were placed under a dissecting scope, animals picked individually with jeweler's forceps without regard to species, gently rinsed with 0.2 µm-filtered seawater and placed in centrifuge tubes containing 90% high-grade, cold acetone solution. The whole procedure was performed under dim, red-light illumination. We typically took triplicate subsamples of 30-100 animals, with the number of individuals depending on the size fraction considered. A similar number of animals per sample was also picked for weight (C,N) determination. The tubes containing the acetone and animals were kept frozen at -20 <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> C for at least 24 h for pigment extraction. The amount of pigment (chlorophyll and phaeopigments) per individual was measured fluorometrically and expressed in terms of chlorophyll (body carbon)<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> (Dam <em>et al.</em>, 1993).</p>
<p>To convert gut pigment values to pigment ingestion rates, knowledge of the gut passage time is necessary. This is typically estimated from the reciprocal of the gut clearance rate constant (GCRC, units of time<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />) of animals placed in filtered seawater (review in Dam and Peterson, 1988). GCRC estimated over the first 30-40 min of gut evacuation is not statistically different from the gut evacuation rate constant of feeding animals (Kiorboe and Tiselius, 1987; Ellis and Small, 1990). We estimated GCRC every time collections for gut pigment were made. To collect animals for gut evacuation experiments, one tow (upper 60 m) was done immediately after the ones for gut fluorescence. We estimated GCRC of animals in the different size fractions (0.2-0.5 mm; 0.5-1.0 mm; 1.0-2-0 mm) by employing the procedure described by Small <em>et al.</em> (1989); i.e., animals were quickly sorted into separate containers, kept in the dark in a temperature-controlled room. We monitored the decline in gut pigment, at 5-min. intervals, over the first 25 min of gut evacuation. Seventy-five per cent of the variance of GCRC is explained by temperature, with a Q<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_1.gif" /><img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_0.gif" /> of 2.2 (Dam and Peterson, 1988). Therefore, we corrected GCRC for differences in temperature from the depth at which animals were collected. Weight-specific ingestion rates for each depth layer were estimated from knowledge of gut pigment and GCRC. The grazing impact of zooplankton was estimated from the product of weight-specific ingestion rates and biomass for each size class.</p>
<p><strong>Literature Cited</strong></p>
<p>Dam, H.G., C.A. Miller and S.H. Jonasdottir (1993). The trophic role of mesozooplankton at 47<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> N, 20<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> W during the North Atlantic Bloom Experiment. Deep-Sea Research, 40: 197-212.</p>
<p>Dam, H.G. and W.T. Peterson (1988). The effect of temperature on the gut clearance rate constant of planktonic copepods. Journal of Experimental Marine Biology and Ecology, 123: 1-14.</p>
<p>Daro, M.H. (1978). A simplified <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_14.gif" />C method for grazing measurements on natural planktonic populations. Helgolander wiss. Meeresunters, 31: 241-248.</p>
<p>Ellis, S.G. and L.F. Small (1989). A comparison of gut evacuation rates of feeding and non-feeding Calanus marshallae. Marine Biology, 103: 175-181.</p>
<p>Kiorboe, T. and P. Tiselius (1987). Gut clearance and pigment destruction in a herbivorous copepod, Acartia tonsa, and the determination of in situ grazing rates. Journal of Plankton Research, 9: 525-534.</p>
<p>Roman, M.R. and P.A. Rublee (1981). A method to determine in situ grazing rates on natural particle assemblages. Marine Biology, 65: 303-309.</p>
<p>Small, L.F., M.R. Landry, R.W. Eppley, F. Azam and A.F. Carlucci (1989). Role of plankton in the carbon and nitrogen budgets of the Santa Monica Basin, California. Marine Ecology Progress Series, 56: 57-74.</p>
<p>Wiebe, P.H., A.W. Morton, A.M. Bradley, R.H. Backus, J.E. Craddock T.J. Cowles, V.A. Barber and G.R. Flierl (1985). New developments in the MOCNESS, an apparatus for sampling zooplankton and micronekton. Marine Biology, 87: 313-323.</p>
from Cruise: TT043 <p>Analysis methodology referenced in:<br />
Roman, M.R. et al, Zooplankton variability on the equator at 140W during the JGOFS EqPac Study. Deep Sea Research II, 42(2-3) : 673-693, 1995</p>
<p><strong>Mesozooplankton Grazing - Isotope Method</strong></p>
<p>Measurements of grazing rates by the radioisotope uptake technique were done day and night, immediately following the MOCNESS tows, in short term, <em>in situ</em> incubations at 1, 10, 30, 50, 70 and 90 m (Roman and Rublee, 1981). Five-liter Plexiglas chambers (General Oceanics) with 64 µm-mesh covering the bottom were lowered 10 m past the desired depths and then raised to concentrate zooplankton in the chambers. A messenger triggered the close of the bottles and released the radioisotope tracers (25 µCi l<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> of methyl<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-3.gif" />H-thymidine, > 75 Ci mmol<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> and 50 µCi l<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> Na<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_2.gif" /> <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_14.gif" />CO<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_3.gif" />, 55.0 Ci mmol<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> ) into the chambers. After a 45-minute incubation on the hydrowire, the chambers were retrieved, zooplankton collected on nested 200 and 64 µm sieves. The zooplankton were rinsed (filtered seawater, 10% HCl and deionized water) onto preweighed 12 µm pore-size Nuclepore filters and dried. Using a dissecting microscope, visible detritus and phytoplankton were removed with a sable brush. The filters were weighed and the weight-specific dpm of the isotopes were measured. Zooplankton carbon was assumed to be 40% of their dry weight to calculate the dpm mg C<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> of the zooplankton. The labelled particulate matter (< 64 µm) was collected on 0.2 µm and 2.0 µm pore-size Nuclepore filters to determine the specific activity of the particulate matter. We derived weight-specific corrections for the absorption and adsorption of the isotopes in shipboard experiments using both filtered seawater and time-0 controls. These corrections were generally less than 10% of experimental values. The isotope activity of the labelled particulate matter (> 2 µm) and zooplankton were used to calculate zooplankton filtration rates, F = liters filtered. mg zooplankton C<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> h<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />, after Daro (1978). The grazing impact of the zooplankton community, expressed as liters filtered m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-3.gif" /> h<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />, was calculated as the product of the weight-specific filtration rate determined from the <em>in situ</em> incubations and the zooplankton biomass in the same depth interval determined immediately prior to the grazing incubation. We used both <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_14.gif" />C bicarbonate and [methyl] <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-3.gif" />H thymidine to estimate the filtration rates of mesozooplankton upon autotrophs (phytoplankton and protozoa that consumed phytoplankton) and heterotrophs (free-living and attached bacteria and protozoa that have consumed bacteria).</p>
<p><strong>Mesozooplankton Grazing - Gut Fluorescence Method</strong></p>
<p>Zooplankton were collected day and night, immediately preceding MOCNESS tows, from vertical tows with opening-closing, 3/4 meter-Puget Sound nets equipped with 200 µm mesh and solid cod ends. Nets were towed to sample depth strata similar to those sampled by the MOCNESS in the upper 120 m. Three depth strata sampled were: 0-20 m, 20-60 m and 60-120 m. The contents of each net was immediately sieved under dim light red light to yield three size fractions: 2.0-1.0 mm; 1.0-0.5 mm and 0.5-0.2 mm. Each fraction was immediately filtered onto a glass fiber filter (GF/A) and frozen at -20<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> C. This procedure took about 5 min. Samples were analyzed in the laboratory ashore. We employed a modification of the procedure described by Dam and Peterson (1988). Thawed samples were placed under a dissecting scope, animals picked individually with jeweler's forceps without regard to species, gently rinsed with 0.2 µm-filtered seawater and placed in centrifuge tubes containing 90% high-grade, cold acetone solution. The whole procedure was performed under dim, red-light illumination. We typically took triplicate subsamples of 30-100 animals, with the number of individuals depending on the size fraction considered. A similar number of animals per sample was also picked for weight (C,N) determination. The tubes containing the acetone and animals were kept frozen at -20 <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> C for at least 24 h for pigment extraction. The amount of pigment (chlorophyll and phaeopigments) per individual was measured fluorometrically and expressed in terms of chlorophyll (body carbon)<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> (Dam <em>et al.</em>, 1993).</p>
<p>To convert gut pigment values to pigment ingestion rates, knowledge of the gut passage time is necessary. This is typically estimated from the reciprocal of the gut clearance rate constant (GCRC, units of time<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />) of animals placed in filtered seawater (review in Dam and Peterson, 1988). GCRC estimated over the first 30-40 min of gut evacuation is not statistically different from the gut evacuation rate constant of feeding animals (Kiorboe and Tiselius, 1987; Ellis and Small, 1990). We estimated GCRC every time collections for gut pigment were made. To collect animals for gut evacuation experiments, one tow (upper 60 m) was done immediately after the ones for gut fluorescence. We estimated GCRC of animals in the different size fractions (0.2-0.5 mm; 0.5-1.0 mm; 1.0-2-0 mm) by employing the procedure described by Small <em>et al.</em> (1989); i.e., animals were quickly sorted into separate containers, kept in the dark in a temperature-controlled room. We monitored the decline in gut pigment, at 5-min. intervals, over the first 25 min of gut evacuation. Seventy-five per cent of the variance of GCRC is explained by temperature, with a Q<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_1.gif" /><img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_0.gif" /> of 2.2 (Dam and Peterson, 1988). Therefore, we corrected GCRC for differences in temperature from the depth at which animals were collected. Weight-specific ingestion rates for each depth layer were estimated from knowledge of gut pigment and GCRC. The grazing impact of zooplankton was estimated from the product of weight-specific ingestion rates and biomass for each size class.</p>
<p><strong>Literature Cited</strong></p>
<p>Dam, H.G., C.A. Miller and S.H. Jonasdottir (1993). The trophic role of mesozooplankton at 47<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> N, 20<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> W during the North Atlantic Bloom Experiment. Deep-Sea Research, 40: 197-212.</p>
<p>Dam, H.G. and W.T. Peterson (1988). The effect of temperature on the gut clearance rate constant of planktonic copepods. Journal of Experimental Marine Biology and Ecology, 123: 1-14.</p>
<p>Daro, M.H. (1978). A simplified <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_14.gif" />C method for grazing measurements on natural planktonic populations. Helgolander wiss. Meeresunters, 31: 241-248.</p>
<p>Ellis, S.G. and L.F. Small (1989). A comparison of gut evacuation rates of feeding and non-feeding Calanus marshallae. Marine Biology, 103: 175-181.</p>
<p>Kiorboe, T. and P. Tiselius (1987). Gut clearance and pigment destruction in a herbivorous copepod, Acartia tonsa, and the determination of in situ grazing rates. Journal of Plankton Research, 9: 525-534.</p>
<p>Roman, M.R. and P.A. Rublee (1981). A method to determine in situ grazing rates on natural particle assemblages. Marine Biology, 65: 303-309.</p>
<p>Small, L.F., M.R. Landry, R.W. Eppley, F. Azam and A.F. Carlucci (1989). Role of plankton in the carbon and nitrogen budgets of the Santa Monica Basin, California. Marine Ecology Progress Series, 56: 57-74.</p>
<p>Wiebe, P.H., A.W. Morton, A.M. Bradley, R.H. Backus, J.E. Craddock T.J. Cowles, V.A. Barber and G.R. Flierl (1985). New developments in the MOCNESS, an apparatus for sampling zooplankton and micronekton. Marine Biology, 87: 313-323.</p>
from Cruise: TT045 <p>Analysis methodology referenced in:<br />
Roman, M.R. et al, Zooplankton variability on the equator at 140W during the JGOFS EqPac Study. Deep Sea Research II, 42(2-3) : 673-693, 1995</p>
<p><strong>Mesozooplankton Grazing - Isotope Method</strong></p>
<p>Measurements of grazing rates by the radioisotope uptake technique were done day and night, immediately following the MOCNESS tows, in short term, <em>in situ</em> incubations at 1, 10, 30, 50, 70 and 90 m (Roman and Rublee, 1981). Five-liter Plexiglas chambers (General Oceanics) with 64 µm-mesh covering the bottom were lowered 10 m past the desired depths and then raised to concentrate zooplankton in the chambers. A messenger triggered the close of the bottles and released the radioisotope tracers (25 µCi l<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> of methyl<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-3.gif" />H-thymidine, > 75 Ci mmol<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> and 50 µCi l<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> Na<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_2.gif" /> <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_14.gif" />CO<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_3.gif" />, 55.0 Ci mmol<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> ) into the chambers. After a 45-minute incubation on the hydrowire, the chambers were retrieved, zooplankton collected on nested 200 and 64 µm sieves. The zooplankton were rinsed (filtered seawater, 10% HCl and deionized water) onto preweighed 12 µm pore-size Nuclepore filters and dried. Using a dissecting microscope, visible detritus and phytoplankton were removed with a sable brush. The filters were weighed and the weight-specific dpm of the isotopes were measured. Zooplankton carbon was assumed to be 40% of their dry weight to calculate the dpm mg C<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> of the zooplankton. The labelled particulate matter (< 64 µm) was collected on 0.2 µm and 2.0 µm pore-size Nuclepore filters to determine the specific activity of the particulate matter. We derived weight-specific corrections for the absorption and adsorption of the isotopes in shipboard experiments using both filtered seawater and time-0 controls. These corrections were generally less than 10% of experimental values. The isotope activity of the labelled particulate matter (> 2 µm) and zooplankton were used to calculate zooplankton filtration rates, F = liters filtered. mg zooplankton C<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> h<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />, after Daro (1978). The grazing impact of the zooplankton community, expressed as liters filtered m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-3.gif" /> h<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />, was calculated as the product of the weight-specific filtration rate determined from the <em>in situ</em> incubations and the zooplankton biomass in the same depth interval determined immediately prior to the grazing incubation. We used both <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_14.gif" />C bicarbonate and [methyl] <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-3.gif" />H thymidine to estimate the filtration rates of mesozooplankton upon autotrophs (phytoplankton and protozoa that consumed phytoplankton) and heterotrophs (free-living and attached bacteria and protozoa that have consumed bacteria).</p>
<p><strong>Mesozooplankton Grazing - Gut Fluorescence Method</strong></p>
<p>Zooplankton were collected day and night, immediately preceding MOCNESS tows, from vertical tows with opening-closing, 3/4 meter-Puget Sound nets equipped with 200 µm mesh and solid cod ends. Nets were towed to sample depth strata similar to those sampled by the MOCNESS in the upper 120 m. Three depth strata sampled were: 0-20 m, 20-60 m and 60-120 m. The contents of each net was immediately sieved under dim light red light to yield three size fractions: 2.0-1.0 mm; 1.0-0.5 mm and 0.5-0.2 mm. Each fraction was immediately filtered onto a glass fiber filter (GF/A) and frozen at -20<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> C. This procedure took about 5 min. Samples were analyzed in the laboratory ashore. We employed a modification of the procedure described by Dam and Peterson (1988). Thawed samples were placed under a dissecting scope, animals picked individually with jeweler's forceps without regard to species, gently rinsed with 0.2 µm-filtered seawater and placed in centrifuge tubes containing 90% high-grade, cold acetone solution. The whole procedure was performed under dim, red-light illumination. We typically took triplicate subsamples of 30-100 animals, with the number of individuals depending on the size fraction considered. A similar number of animals per sample was also picked for weight (C,N) determination. The tubes containing the acetone and animals were kept frozen at -20 <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> C for at least 24 h for pigment extraction. The amount of pigment (chlorophyll and phaeopigments) per individual was measured fluorometrically and expressed in terms of chlorophyll (body carbon)<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> (Dam <em>et al.</em>, 1993).</p>
<p>To convert gut pigment values to pigment ingestion rates, knowledge of the gut passage time is necessary. This is typically estimated from the reciprocal of the gut clearance rate constant (GCRC, units of time<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />) of animals placed in filtered seawater (review in Dam and Peterson, 1988). GCRC estimated over the first 30-40 min of gut evacuation is not statistically different from the gut evacuation rate constant of feeding animals (Kiorboe and Tiselius, 1987; Ellis and Small, 1990). We estimated GCRC every time collections for gut pigment were made. To collect animals for gut evacuation experiments, one tow (upper 60 m) was done immediately after the ones for gut fluorescence. We estimated GCRC of animals in the different size fractions (0.2-0.5 mm; 0.5-1.0 mm; 1.0-2-0 mm) by employing the procedure described by Small <em>et al.</em> (1989); i.e., animals were quickly sorted into separate containers, kept in the dark in a temperature-controlled room. We monitored the decline in gut pigment, at 5-min. intervals, over the first 25 min of gut evacuation. Seventy-five per cent of the variance of GCRC is explained by temperature, with a Q<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_1.gif" /><img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_0.gif" /> of 2.2 (Dam and Peterson, 1988). Therefore, we corrected GCRC for differences in temperature from the depth at which animals were collected. Weight-specific ingestion rates for each depth layer were estimated from knowledge of gut pigment and GCRC. The grazing impact of zooplankton was estimated from the product of weight-specific ingestion rates and biomass for each size class.</p>
<p><strong>Literature Cited</strong></p>
<p>Dam, H.G., C.A. Miller and S.H. Jonasdottir (1993). The trophic role of mesozooplankton at 47<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> N, 20<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> W during the North Atlantic Bloom Experiment. Deep-Sea Research, 40: 197-212.</p>
<p>Dam, H.G. and W.T. Peterson (1988). The effect of temperature on the gut clearance rate constant of planktonic copepods. Journal of Experimental Marine Biology and Ecology, 123: 1-14.</p>
<p>Daro, M.H. (1978). A simplified <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_14.gif" />C method for grazing measurements on natural planktonic populations. Helgolander wiss. Meeresunters, 31: 241-248.</p>
<p>Ellis, S.G. and L.F. Small (1989). A comparison of gut evacuation rates of feeding and non-feeding Calanus marshallae. Marine Biology, 103: 175-181.</p>
<p>Kiorboe, T. and P. Tiselius (1987). Gut clearance and pigment destruction in a herbivorous copepod, Acartia tonsa, and the determination of in situ grazing rates. Journal of Plankton Research, 9: 525-534.</p>
<p>Roman, M.R. and P.A. Rublee (1981). A method to determine in situ grazing rates on natural particle assemblages. Marine Biology, 65: 303-309.</p>
<p>Small, L.F., M.R. Landry, R.W. Eppley, F. Azam and A.F. Carlucci (1989). Role of plankton in the carbon and nitrogen budgets of the Santa Monica Basin, California. Marine Ecology Progress Series, 56: 57-74.</p>
<p>Wiebe, P.H., A.W. Morton, A.M. Bradley, R.H. Backus, J.E. Craddock T.J. Cowles, V.A. Barber and G.R. Flierl (1985). New developments in the MOCNESS, an apparatus for sampling zooplankton and micronekton. Marine Biology, 87: 313-323.</p>
from Cruise: TT050 <p>Analysis methodology referenced in:<br />
Roman, M.R. et al, Zooplankton variability on the equator at 140W during the JGOFS EqPac Study. Deep Sea Research II, 42(2-3) : 673-693, 1995</p>
<p><strong>Mesozooplankton Grazing - Isotope Method</strong></p>
<p>Measurements of grazing rates by the radioisotope uptake technique were done day and night, immediately following the MOCNESS tows, in short term, <em>in situ</em> incubations at 1, 10, 30, 50, 70 and 90 m (Roman and Rublee, 1981). Five-liter Plexiglas chambers (General Oceanics) with 64 µm-mesh covering the bottom were lowered 10 m past the desired depths and then raised to concentrate zooplankton in the chambers. A messenger triggered the close of the bottles and released the radioisotope tracers (25 µCi l<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> of methyl<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-3.gif" />H-thymidine, > 75 Ci mmol<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> and 50 µCi l<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> Na<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_2.gif" /> <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_14.gif" />CO<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_3.gif" />, 55.0 Ci mmol<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> ) into the chambers. After a 45-minute incubation on the hydrowire, the chambers were retrieved, zooplankton collected on nested 200 and 64 µm sieves. The zooplankton were rinsed (filtered seawater, 10% HCl and deionized water) onto preweighed 12 µm pore-size Nuclepore filters and dried. Using a dissecting microscope, visible detritus and phytoplankton were removed with a sable brush. The filters were weighed and the weight-specific dpm of the isotopes were measured. Zooplankton carbon was assumed to be 40% of their dry weight to calculate the dpm mg C<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> of the zooplankton. The labelled particulate matter (< 64 µm) was collected on 0.2 µm and 2.0 µm pore-size Nuclepore filters to determine the specific activity of the particulate matter. We derived weight-specific corrections for the absorption and adsorption of the isotopes in shipboard experiments using both filtered seawater and time-0 controls. These corrections were generally less than 10% of experimental values. The isotope activity of the labelled particulate matter (> 2 µm) and zooplankton were used to calculate zooplankton filtration rates, F = liters filtered. mg zooplankton C<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> h<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />, after Daro (1978). The grazing impact of the zooplankton community, expressed as liters filtered m<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-3.gif" /> h<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />, was calculated as the product of the weight-specific filtration rate determined from the <em>in situ</em> incubations and the zooplankton biomass in the same depth interval determined immediately prior to the grazing incubation. We used both <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_14.gif" />C bicarbonate and [methyl] <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-3.gif" />H thymidine to estimate the filtration rates of mesozooplankton upon autotrophs (phytoplankton and protozoa that consumed phytoplankton) and heterotrophs (free-living and attached bacteria and protozoa that have consumed bacteria).</p>
<p><strong>Mesozooplankton Grazing - Gut Fluorescence Method</strong></p>
<p>Zooplankton were collected day and night, immediately preceding MOCNESS tows, from vertical tows with opening-closing, 3/4 meter-Puget Sound nets equipped with 200 µm mesh and solid cod ends. Nets were towed to sample depth strata similar to those sampled by the MOCNESS in the upper 120 m. Three depth strata sampled were: 0-20 m, 20-60 m and 60-120 m. The contents of each net was immediately sieved under dim light red light to yield three size fractions: 2.0-1.0 mm; 1.0-0.5 mm and 0.5-0.2 mm. Each fraction was immediately filtered onto a glass fiber filter (GF/A) and frozen at -20<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> C. This procedure took about 5 min. Samples were analyzed in the laboratory ashore. We employed a modification of the procedure described by Dam and Peterson (1988). Thawed samples were placed under a dissecting scope, animals picked individually with jeweler's forceps without regard to species, gently rinsed with 0.2 µm-filtered seawater and placed in centrifuge tubes containing 90% high-grade, cold acetone solution. The whole procedure was performed under dim, red-light illumination. We typically took triplicate subsamples of 30-100 animals, with the number of individuals depending on the size fraction considered. A similar number of animals per sample was also picked for weight (C,N) determination. The tubes containing the acetone and animals were kept frozen at -20 <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> C for at least 24 h for pigment extraction. The amount of pigment (chlorophyll and phaeopigments) per individual was measured fluorometrically and expressed in terms of chlorophyll (body carbon)<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" /> (Dam <em>et al.</em>, 1993).</p>
<p>To convert gut pigment values to pigment ingestion rates, knowledge of the gut passage time is necessary. This is typically estimated from the reciprocal of the gut clearance rate constant (GCRC, units of time<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny-1.gif" />) of animals placed in filtered seawater (review in Dam and Peterson, 1988). GCRC estimated over the first 30-40 min of gut evacuation is not statistically different from the gut evacuation rate constant of feeding animals (Kiorboe and Tiselius, 1987; Ellis and Small, 1990). We estimated GCRC every time collections for gut pigment were made. To collect animals for gut evacuation experiments, one tow (upper 60 m) was done immediately after the ones for gut fluorescence. We estimated GCRC of animals in the different size fractions (0.2-0.5 mm; 0.5-1.0 mm; 1.0-2-0 mm) by employing the procedure described by Small <em>et al.</em> (1989); i.e., animals were quickly sorted into separate containers, kept in the dark in a temperature-controlled room. We monitored the decline in gut pigment, at 5-min. intervals, over the first 25 min of gut evacuation. Seventy-five per cent of the variance of GCRC is explained by temperature, with a Q<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_1.gif" /><img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_0.gif" /> of 2.2 (Dam and Peterson, 1988). Therefore, we corrected GCRC for differences in temperature from the depth at which animals were collected. Weight-specific ingestion rates for each depth layer were estimated from knowledge of gut pigment and GCRC. The grazing impact of zooplankton was estimated from the product of weight-specific ingestion rates and biomass for each size class.</p>
<p><strong>Literature Cited</strong></p>
<p>Dam, H.G., C.A. Miller and S.H. Jonasdottir (1993). The trophic role of mesozooplankton at 47<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> N, 20<img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_o.gif" /> W during the North Atlantic Bloom Experiment. Deep-Sea Research, 40: 197-212.</p>
<p>Dam, H.G. and W.T. Peterson (1988). The effect of temperature on the gut clearance rate constant of planktonic copepods. Journal of Experimental Marine Biology and Ecology, 123: 1-14.</p>
<p>Daro, M.H. (1978). A simplified <img src="https://datadocs.bco-dmo.org/static/usjgofs.whoi.edu/smallgifs/tiny_14.gif" />C method for grazing measurements on natural planktonic populations. Helgolander wiss. Meeresunters, 31: 241-248.</p>
<p>Ellis, S.G. and L.F. Small (1989). A comparison of gut evacuation rates of feeding and non-feeding Calanus marshallae. Marine Biology, 103: 175-181.</p>
<p>Kiorboe, T. and P. Tiselius (1987). Gut clearance and pigment destruction in a herbivorous copepod, Acartia tonsa, and the determination of in situ grazing rates. Journal of Plankton Research, 9: 525-534.</p>
<p>Roman, M.R. and P.A. Rublee (1981). A method to determine in situ grazing rates on natural particle assemblages. Marine Biology, 65: 303-309.</p>
<p>Small, L.F., M.R. Landry, R.W. Eppley, F. Azam and A.F. Carlucci (1989). Role of plankton in the carbon and nitrogen budgets of the Santa Monica Basin, California. Marine Ecology Progress Series, 56: 57-74.</p>
<p>Wiebe, P.H., A.W. Morton, A.M. Bradley, R.H. Backus, J.E. Craddock T.J. Cowles, V.A. Barber and G.R. Flierl (1985). New developments in the MOCNESS, an apparatus for sampling zooplankton and micronekton. Marine Biology, 87: 313-323.</p>
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MOCNESS.25
MOCNESS.25
PI Supplied Instrument Name: MOCNESS.25 PI Supplied Instrument Description:Mesozooplankton (> 64 µm) were collected from day/night pairs of tows with a 0.25 m-mouth area MOCNESS equipped with nine nets with a 7:1, mouth:length ratio (Wiebe et al., 1985). Instrument Name: MOCNESS.25 Instrument Short Name:MOC.25 Instrument Description: The Multiple Opening/Closing Net and Environmental Sensing System or MOCNESS is a family of net systems based on the Tucker Trawl principle. The MOCNESS-1/4 carries nine 1/4-m2 nets usually of 64 micrometer mesh and is used to sample the larger micro-zooplankton. Community Standard Description: http://vocab.nerc.ac.uk/collection/L22/current/NETT0097/
Cruise: TT043
TT043
R/V Thomas G. Thompson
Community Standard Description
International Council for the Exploration of the Sea
R/V Thomas G. Thompson
vessel
TT043
Michael R. Roman
University of Maryland Center for Environmental Science
http://osprey.bcodmo.org/datasetDeployment.cfm?ddid=2580&did=353&flag=view
Report describing TT043
Cruise: TT045
TT045
R/V Thomas G. Thompson
Community Standard Description
International Council for the Exploration of the Sea
R/V Thomas G. Thompson
vessel
TT045
John F. Marra
Lamont-Doherty Earth Observatory
Cruise: TT050
TT050
R/V Thomas G. Thompson
Community Standard Description
International Council for the Exploration of the Sea
R/V Thomas G. Thompson
vessel
TT050
Sharon L. Smith
University of Miami
R/V Thomas G. Thompson
Community Standard Description
International Council for the Exploration of the Sea
R/V Thomas G. Thompson
vessel