MOCNESS summary data from Gulf of Maine krill cruises from R/V Endeavor, R/V Connecticut EN484, EN487, CT2010 in the Gulf of Maine, Georges Bank, Southern New England Shelf and Slope Water from 2010-2010 (Krill GoME project)

Website: https://www.bco-dmo.org/dataset/3402
Version: 12/29/2010
Version Date: 2010-12-29

Project
» Biological and Physical Determinants of Euphausiid Aggregation, Behavior, and Interaction with Higher Predators at an Abrupt Topographical Feature in the Gulf of Maine (Krill GoME)
ContributorsAffiliationRole
Lawson, GarethWoods Hole Oceanographic Institution (WHOI)Principal Investigator
Wiebe, Peter H.Woods Hole Oceanographic Institution (WHOI)Co-Principal Investigator
Copley, NancyWoods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager


Dataset Description

Summary of environmental data collected by the MOCNESS system's (1 meter-square) electronics package.


Data Processing Description

Nov. 29, 2010:
Revised MOCNESS files for recomputed volumes using new flow meter calibration value determined on R/V Connecticut and R/V Endeavor (EN487). See write-up decribing the calibration procedure in EN487 cruise report. The volume revisions were done by Peter Wiebe using a flow meter calibration value of 6.41, which was the average of the values determined on the two cruises. The following is a list of the files used (raw) and produced (pro, tab) to compute the volumes filtered.

Date revised  Raw file Used      New Pro file    New Tab file
R/V Endeavor (EN484) Tows:
17Nov2010   M_01_1.raw        M001.pro          M001.tab
17Nov2010   M_1_002.raw      M002.pro          M002.tab
17Nov2010   M_01_003.raw    M003.pro          M003.tab
 Note: M_1_004.raw modified to eliminate extra headers due to restarts before tow actually started. 
17Nov2010   M_1_004.raw      M004.pro          M004.tab

R/V Endeavor (EN487) Tows:
17Nov2010   M_1_1.raw           M001.pro          M001.tab
17Nov2010   M_1_002.raw      M002.pro          M002.tab
17Nov2010   M_01_003.raw    M003.pro          M003.tab
  Note: M_1_004.raw modified to eliminate extra lines at start of tow. 
17Nov2010   M_1_004.raw      M004.pro          M004.tab
17Nov2010   M_01_005.raw    M005.pro          M005.tab

R/V Connecticut tows:
18Nov2010 - modified M_01_002.raw to eliminate start and end data when net out of the water and also removed the "#increment_net" indicator for net 2 because it apparently did not open at the 600 m mark. Net 8 was opened at the surface and taking out this indicator provides the volumes for the towing scenario indicated on the log sheets.
18Nov2010   M_1_002.raw      M002.pro          M002.tab
18Nov2010 - modified M_01_003.raw to eliminate end data when net out of the water and also modifed the "#increment_net" indicator in all cases so that the postprocessing would ignore the indicator. In addition all of the "+" indicators were changed to "-" to prevent spurious net number changes in the raw file from indicating a net bar had been dropped except that a "+" was added at the end of the raw file along with an "#increment_net" indicator to make the program calculate the total volume filtered for the tow. This was done because none of the nets were opened or closed on the tow. See log notes for additional details.
18Nov2010   M_1_003.raw      M003.pro          M003.tab
18Nov2010 - modified M_01_005 to eliminate end data when net out of the water and  a "+" was added at the end of the raw file along with an "#increment_net" indicator to make the program calculate the total volume filtered for the third net that was not closed at the surface.
18Nov2010   M_1_005.raw      M005.pro          M005.tab
18Nov2010   M_01_006.raw    M006.pro          M006.tab
18Nov2010   M_01_006.raw    M007.pro          M007.tab
18Nov2010   M_01_008.raw    M008.pro          M008.tab
18Nov2010 - modified M_01_009 to eliminate 2nd header that was present becuase program had to be restarted during net 8 open.
18Nov2010   M_1_009.raw     M009.pro          M009.tab
18Nov2010 - modified M_01_012 by modifying the "#increment_net" indicator so that it would be ignored since a delayed net response took place after it was issued for end of net 8. 
18Nov2010   M_1_012.raw     M012.pro          M012.tabto be restarted during net 8 open.


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Data Files

File
mocness_tabs.csv
(Comma Separated Values (.csv), 28.37 KB)
MD5:6aef482cf3285549d54ebc4a4ae852e8
Primary data file for dataset ID 3402

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Parameters

ParameterDescriptionUnits
tow

tow number

lat_start

latitude start of MOCNESS cast, negative = South

DD.D
lon_start

longitude start of MOCNESS cast, negative = West

DDD.D
depth_w

depth of water, seafloor depth from the shipboard 12kHz Knudsen echosounder; seafloor in eventlog

meters
net

MOCNESS net number, (0-8)

yrday_local

year day as a decimal, based on Julian calendar, local time

YYY.Y
num_obs

number of observations

vol_filt

volume filtered

meters^3
press

depth of observation or sample

psi
temp

temperature of water

degrees C
potemp

potential temperature or theta

degrees C
sal

salinity calculated from conductivity

sigma_0

potential density

kg/m^3
angle

angle of net frame relative to vertical (0-89 degrees)

degrees
hzvel

horizontal net velocity

m/min
vtvel_min

Minimum vertical net velocity for each net measured during mocness tows.

m/min
press_avg

average pressure for a net sample

psi
angle_min

Minimum angle of tow body relative to vertical (0-89 degrees), used in BIOMAPER-II and MOCNESS systems.

degrees
angle_max

Maximum angle of tow body relative to vertical (0-89 degrees), used in BIOMAPER-II and MOCNESS systems.

degrees
angle_avg

Angle of tow body relative to vertical (0-89 degrees), used in BIOMAPER-II and MOCNESS systems.
Average is the mean of all observations, not just the mean of the global minimum and maximum.

decimal degrees
hzvel_min

Minimum horizontal net velocity, reported as meters per minute, used in MOCNESS system.

m/min
hzvel_max

Maximum horizontal net velocity, reported as meters per minute, used in MOCNESS system.

m/min
hzvel_avg

Average horizontal net velocity, reported as meters per minute, used in MOCNESS system.
Average is the mean of all observations, not just the mean of the global minimum and maximum.

m/min
potemp_min

Minimum potential temperature (International Practical Temperature Scale - 68 ,or 90. When known, the scale will be reported in the units field of the documentation file.

degrees Celsius
potemp_max

Maximum potential temperature (International Practical Temperature Scale - 68 ,or 90. When known, the scale will be reported in the units field of the documentation file.

degrees Celsius
potemp_avg

Average potential temperature (International Practical Temperature Scale - 68 ,or 90. When known, the scale will be reported in the units field of the documentation file.

Average is the mean of all observations, not just the mean of the global minimum and maximum.

degrees Celsius
press_min

Minimum water pressure at measurement; depth reported as pressure; positive number increasing with water depth.

psi
press_max

Maximum water pressure at measurement; depth reported as pressure; positive number increasing with water depth.

psi
sal_min

Minimum salinity calculated from conductivity.

dimmensionless
sal_max

Maximum salinity calculated from conductivity.

dimmensionless
sal_avg

Average salinity calculated from conductivity.
Average is the mean of all observations, not just the mean of the global minimum and maximum.

dimmensionless
sigma_0_min

Minimum potential density.

kilograms/meter^3
sigma_0_max

Maximum postential density.

kilograms/meter^3
sigma_0_avg

Average potential density. Average is the mean of all observations, not just the mean of the global minimum and maximum.

kilograms/meter^3
vtvel_max

Maximum vertical net velocity for each net measured during mocness tows.

m/min
vtvel_avg

Average vertical net velocity for each net measured during mocness tows.
Average is the mean of all observations, not just the mean of the global minimum and maximum.

m/min
temp_min

Minimum water temperature for each net measured during mocness tows.

degrees Celsius
temp_max

Maximum water temperature for each net measured during mocness tows.

degrees Celsius
temp_avg

Average water temperature for each net measured during mocness tows.
Average is the mean of all observations, not just the mean of the global minimum and maximum.

degrees Celsius
cruiseid

Cruise identifier (e.g. EN484 = R/V Endeavor cruise 484).

unitless


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Instruments

Dataset-specific Instrument Name
MOCNESS1
Generic Instrument Name
MOCNESS1
Generic 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 carries nine 1-m2 nets usually of 335 micrometer mesh and is intended for use with the macrozooplankton. All nets are black to reduce contrast with the background. A motor/toggle release assembly is mounted on the top portion of the frame and stainless steel cables with swaged fittings are used to attach the net bar to the toggle release. A stepping motor in a pressure compensated case filled with oil turns the escapement crankshaft of the toggle release which sequentially releases the nets to an open then closed position on command from the surface. -- from the MOCNESS Operations Manual (1999 + 2003).


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Deployments

EN484

Website
Platform
R/V Endeavor
Report
Start Date
2010-09-22
End Date
2010-09-30
Description
Cruise EN484, Chief Scientist Gareth Lawson's September 2010 Krill cruise to the northern flank of Georges Bank and the southern portion of the Gulf of Maine region (42 North 67.5 West), is the first of two cruises in Fall 2010 doing the same work in the same study location. The cruise was scheduled to allow an examination of the impact of herring predation on euphausiid aggregations. The first cruise each year (two similar cruises are planned for 2011) is timed to begin one week after the NOAA Ship Delaware II will have commenced its herring survey. Real-time data collected during that survey will be used to define the exact survey grid for our project. During EN484, the first 2010 cruise, the herring were expected to be pre-spawning and therefore not feeding on euphausiids (the target species for this project). The second cruise each year is timed to begin in the last week of October (EN487 in 2010). At this time, herring and euphausiids will still be present in the study region, but the herring will be post-spawning and will have resumed feeding on euphausiids. Cruise information and original data are available from the NSF R2R data catalog.

Processing Description
 See Dataset Description - Processing for notes.

EN487

Website
Platform
R/V Endeavor
Report
Start Date
2010-10-27
End Date
2010-11-06
Description
Cruise EN487, Chief Scientist Gareth Lawson's October-November 2010 Krill cruise to the northern flank of Georges Bank and the southern portion of the Gulf of Maine region (42 North 67.5 West), is the second of two cruises completed for the Gulf of Maine Krill project in Fall 2010.  The cruises were designed to conduct the same work in the same study location. The timing of the cruises was selected to allow an examination of the impact of herring predation on euphausiid aggregations. The first cruise (cruise EN484 in 2010) each year (two similar cruises are planned for 2011) is timed to begin one week after the NOAA Ship Delaware II will have commenced its herring survey. Real-time data collected during that survey will be used to define the exact survey grid for our project. During the first cruise, EN484, the herring were expected to be pre-spawning and therefore not feeding on euphausiids (the target species for this project). The second cruise each year (EN487 in 2010) is timed to begin in the last week of October. At this time, herring and euphausiids will still be present in the study region, but the herring will be post-spawning and will have resumed feeding on euphausiids. EN487 cruise track JPEG image from URI (vessel operator) Cruise information and original data are available from the NSF R2R data catalog.

CT2010

Website
Platform
R/V Connecticut
Start Date
2010-07-08
End Date
2010-07-16
Description
The CT2010 cruise was supported by funds from Woods Hole Sea Grant, and field work was done on the southern New England Shelf and in nearby slope waters.  This is a different study area from the sites visited by the other Krill project cruises that sampled in the Gulf of Maine.


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Project Information

Biological and Physical Determinants of Euphausiid Aggregation, Behavior, and Interaction with Higher Predators at an Abrupt Topographical Feature in the Gulf of Maine (Krill GoME)

Coverage: Gulf of Maine; Georges Bank


from the NSF award abstract:

Distribution, Aggregation, and Ecological Importance of Euphausids in the Gulf of Maine Region

Zooplankton are key members of marine ecosystems, but the biological and physical factors governing their distribution and aggregation are not fully understood, especially at the continental shelf break and margins of the deep basins of the shelf. Euphausiids are an important group of crustacean zooplankton in North Atlantic pelagic food webs and represent an interesting model species for the study of zooplankton aggregation due to their strong swimming capabilities and active aggregative behaviors. This project will address the hypotheses that the formation and variability of euphausiid aggregations along the northern flank of Georges Bank and the southern portion of the Gulf of Maine during fall relate to the interaction of physical concentration mechanisms with local topography and with plasticity in diel vertical migration and active aggregative behaviors, and that this plasticity arises from variability in food availability and predation by herring. These hypotheses will be addressed through a field program employing a comprehensive array of sensors, including both conventional narrowband and recently-developed broadband acoustic systems to sample the euphausiids, and a variety of other acoustic, optical, net, and other sampling devices to quantify their physical and biological environment. These sensors will be used in an inventive combination of (1) coarse-scale grid surveys to characterize along- and across-slope variability in the distribution of euphausiids, their predators, other zooplankton, phytoplankton, and physical conditions (e.g., the flow field), and (2) fine-scale adaptive surveys used to track individual euphausiid aggregations and observe how their three-dimensional structure and vertical position vary with changing environmental conditions. Repeat surveys will be timed to capitalize on known or likely variations in the flow field, food availability, light levels, and predation.



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Funding

Funding SourceAward
NSF Division of Ocean Sciences (NSF OCE)

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